A phase II, multicenter, open-label study of abemaciclib and letrozole in patients with estrogen receptor-positive rare ovarian cancer: ALEPRO trial

BACKGROUND

Low-grade serous and endometrioid ovarian cancers and adult-type granulosa cell tumors are rare ovarian malignancies that show high estrogen receptor positivity. Recurrences of these subtypes of ovarian cancer are often treated with conventional chemotherapy, although response rates are disappointing.

PRIMARY OBJECTIVE

To determine the overall response rate of the combination therapy of abemaciclib and letrozole in patients with estrogen receptor-positive rare ovarian cancers.

STUDY HYPOTHESIS

The combination therapy of abemaciclib and letrozole will provide a clinically meaningful therapeutic benefit, with an overall response rate of >25%.

TRIAL DESIGN

This is a phase II, international, multicenter, open-label, single-arm study to evaluate the efficacy and safety of abemaciclib and letrozole in patients with advanced, recurrent, and/or metastatic estrogen receptor-positive, rare ovarian cancer. The study will follow a tandem two-stage design.

MAJOR INCLUSION/EXCLUSION CRITERIA

Patients must have histologically confirmed low-grade serous/endometrioid ovarian cancer or adult-type granulosa cell tumor with estrogen receptor positivity on immunohistochemistry. Patients need to have recurrent and measurable disease according to Radiologic Evaluation Criteria in Solid Tumors (RECIST) version 1.1. A maximum of two prior lines of endocrine therapy are allowed, and patients cannot have previously received a cyclin-dependent kinase inhibitor. Patients with platinum-refractory disease are not allowed in any stage of the study.

PRIMARY ENDPOINT

Investigator-assessed confirmed overall response rate, defined as the proportion of patients with a complete or partial response according to RECIST v1.1.

SAMPLE SIZE

40 to 100 patients will be included, depending on the results of the interim analysis. Patients will be included in Belgium, France and the Netherlands.

ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS

Patient recruitment will be completed by the end of 2025 and reporting of the final study results will be done by the end of 2027.

TRIAL REGISTRATION NUMBER

NCT05872204.

Durvalumab Plus Carboplatin/Paclitaxel Followed by Maintenance Durvalumab With or Without Olaparib as First-Line Treatment for Advanced Endometrial Cancer: The Phase III DUO-E Trial

PURPOSE

Immunotherapy and chemotherapy combinations have shown activity in endometrial cancer, with greater benefit in mismatch repair (MMR)-deficient (dMMR) than MMR-proficient (pMMR) disease. Adding a poly(ADP-ribose) polymerase inhibitor may improve outcomes, especially in pMMR disease.

METHODS

This phase III, global, double-blind, placebo-controlled trial randomly assigned eligible patients with newly diagnosed advanced or recurrent endometrial cancer 1:1:1 to: carboplatin/paclitaxel plus durvalumab placebo followed by placebo maintenance (control arm); carboplatin/paclitaxel plus durvalumab followed by maintenance durvalumab plus olaparib placebo (durvalumab arm); or carboplatin/paclitaxel plus durvalumab followed by maintenance durvalumab plus olaparib (durvalumab + olaparib arm). The primary end points were progression-free survival (PFS) in the durvalumab arm versus control and the durvalumab + olaparib arm versus control.

RESULTS

Seven hundred eighteen patients were randomly assigned. In the intention-to-treat population, statistically significant PFS benefit was observed in the durvalumab (hazard ratio [HR], 0.71 [95% CI, 0.57 to 0.89]; P = .003) and durvalumab + olaparib arms (HR, 0.55 [95% CI, 0.43 to 0.69]; P < .0001) versus control. Prespecified, exploratory subgroup analyses showed PFS benefit in dMMR (HR [durvalumab v control], 0.42 [95% CI, 0.22 to 0.80]; HR [durvalumab + olaparib v control], 0.41 [95% CI, 0.21 to 0.75]) and pMMR subgroups (HR [durvalumab v control], 0.77 [95% CI, 0.60 to 0.97]; HR [durvalumab + olaparib v control] 0.57; [95% CI, 0.44 to 0.73]); and in PD-L1-positive subgroups (HR [durvalumab v control], 0.63 [95% CI, 0.48 to 0.83]; HR [durvalumab + olaparib v control], 0.42 [95% CI, 0.31 to 0.57]). Interim overall survival results (maturity approximately 28%) were supportive of the primary outcomes (durvalumab v control: HR, 0.77 [95% CI, 0.56 to 1.07]; P = .120; durvalumab + olaparib v control: HR, 0.59 [95% CI, 0.42 to 0.83]; P = .003). The safety profiles of the experimental arms were generally consistent with individual agents.

CONCLUSION

Carboplatin/paclitaxel plus durvalumab followed by maintenance durvalumab with or without olaparib demonstrated a statistically significant and clinically meaningful PFS benefit in patients with advanced or recurrent endometrial cancer.

Tisotumab Vedotin in Combination With Carboplatin, Pembrolizumab, or Bevacizumab in Recurrent or Metastatic Cervical Cancer: Results From the innovaTV 205/GOG-3024/ENGOT-cx8 Study

PURPOSE

Tissue factor is highly expressed in cervical carcinoma and can be targeted by tisotumab vedotin (TV), an antibody-drug conjugate. This phase Ib/II study evaluated TV in combination with bevacizumab, pembrolizumab, or carboplatin for recurrent or metastatic cervical cancer (r/mCC).

METHODS

This open-label, multicenter study (ClinicalTrials.gov identifier: NCT03786081) included dose-escalation arms that assessed dose-limiting toxicities (DLTs) and identified the recommended phase II dose (RP2D) of TV in combination with bevacizumab (arm A), pembrolizumab (arm B), or carboplatin (arm C). The dose-expansion arms evaluated TV antitumor activity and safety at RP2D in combination with carboplatin as first-line (1L) treatment (arm D) or with pembrolizumab as 1L (arm E) or second-/third-line (2L/3L) treatment (arm F). The primary end point of dose expansion was objective response rate (ORR).

RESULTS

A total of 142 patients were enrolled. In dose escalation (n = 41), no DLTs were observed; the RP2D was TV 2 mg/kg plus bevacizumab 15 mg/kg on day 1 once every 3 weeks, pembrolizumab 200 mg on day 1 once every 3 weeks, or carboplatin AUC 5 on day 1 once every 3 weeks. In dose expansion (n = 101), the ORR was 54.5% (n/N, 18/33; 95% CI, 36.4 to 71.9) with 1L TV + carboplatin (arm D), 40.6% (n/N, 13/32; 95% CI, 23.7 to 59.4) with 1L TV + pembrolizumab (arm E), and 35.3% (12/34; 19.7 to 53.5) with 2L/3L TV + pembrolizumab (arm F). The median duration of response was 8.6 months, not reached, and 14.1 months, in arms D, E, and F, respectively. Grade ≥3 adverse events (≥15%) were anemia, diarrhea, nausea, and thrombocytopenia in arm D and anemia in arm F (none ≥15%, arm E).

CONCLUSION

TV in combination with bevacizumab, carboplatin, or pembrolizumab demonstrated manageable safety and encouraging antitumor activity in treatment-naive and previously treated r/mCC.

Predicting resectable disease in relapsed epithelial ovarian cancer by using whole-body diffusion-weighted MRI

OBJECTIVE

To determine the diagnostic value of whole-body diffusion-weighted magnetic resonance imaging (WB-DWI/MRI) to predict resectable disease at the time of secondary cytoreductive surgery for relapsed epithelial ovarian cancer with a platinum-free interval of at least 6 months.

METHODS

A retrospective cohort study between January 2012 and December 2021 in a tertiary referral hospital. Inclusion criteria were: (a) first recurrence of epithelial ovarian cancer; (b) platinum-free interval of ≥6 months; (c) intent to perform secondary cytoreductive surgery with complete macroscopic resection; and (d) WB-DWI/MRI was performed.Diagnostic tests of WB-DWI/MRI for predicting complete resection during secondary cytoreductive surgery are calculated as well as the progression-free and overall survival of the patients with a WB-DWI/MRI scan that showed resectable disease or not.

RESULTS

In total, 238 patients could be identified, of whom 123 (51.7%) underwent secondary cytoreductive surgery. WB-DWI/MRI predicted resectable disease with a sensitivity of 93.6% (95% confidence interval [CI] 87.3% to 96.9%), specificity of 93.0% (95% CI 87.3% to 96.3%), and an accuracy of 93.3% (95% CI 89.3% to 96.1%). The positive predictive value was 91.9% (95% CI 85.3% to 95.7%).Prediction of resectable disease by WB-DWI/MRI correlated with improved progression-free survival (median 19 months vs 9 months; hazard ratio [HR] for progression 0.36; 95% CI 0.26 to 0.50) and overall survival (median 75 months vs 28 months; HR for death 0.33; 95% CI 0.23 to 0.47).

CONCLUSION

WB-DWI/MRI accurately predicts resectable disease in patients with a platinum-free interval of ≥6 months at the time of secondary cytoreductive surgery and could be of complementary value to the currently used models.

NIRVANA-1: maintenance therapy with niraparib versus niraparib-bevacizumab in patients with advanced ovarian cancer

Following the results of the PRIMA and PAOLA-1 trials, the most effective maintenance strategy for International Federation of Gynecology and Obstetrics stage III patients is still debated, raising the question which of those two maintenance strategies is the most effective: PARP inhibitors alone or PARP inhibitors in combination with bevacizumab. The ongoing NIRVANA-1 study will try to answer this question by assessing the efficacy and safety of niraparib + bevacizumab in comparison with niraparib alone after adjuvant chemotherapy for completely resected stage III patients. Stratification factors include tumor BRCA status, International Federation of Gynecology and Obstetrics stage (IIIA vs IIIB/IIIC) and the use of hyperthermic intraperitoneal chemotherapy during surgery - within the OVHIPEC-2 trial. The primary end point will be progression-free survival rate at 24 months. Safety, median progression-free survival and overall survival will also be studied.

PARP inhibitor predictive value of the Leuven HRD test compared with Myriad MyChoice CDx PLUS HRD on 468 ovarian cancer patients from the PAOLA-1/ENGOT-ov25 trial

BACKGROUND

The PAOLA-1/ENGOT-ov25 trial showed improved progression-free (PFS) and overall survival (OS) in homologous recombination deficient (HRD) positive patients treated with olaparib, but not when HRD negative (HRD tested with MyChoice CDx PLUS [Myriad test]).

PATIENTS AND METHODS

The academic Leuven HRD test consists of capture-based targeted sequencing of genome-wide single-nucleotide polymorphisms and coding exons of eight HR genes including BRCA1, BRCA2, and TP53. We compared the predictive value of the Leuven HRD versus Myriad HRD test for PFS and OS in the randomised PAOLA-1 trial.

RESULTS

468 patients had left-over DNA after Myriad testing for Leuven HRD testing. Positive/negative/overall percent agreement for the Leuven versus Myriad HRD status was 95%/86%/91%, respectively. Tumours were HRD+ in 55% and 52%, respectively. In Leuven HRD+ patients, 5years PFS (5yPFS) was 48.6% versus 20.3% (HR 0.431; 95% confidence intervals (CI) 0.312-0.595) for olaparib versus placebo, respectively (Myriad test 0.409; 95% CI 0.292-0.572). In Leuven HRD+/BRCAwt patients 5yPFS was 41.3% versus 12.6% (HR 0.497; 95% CI 0.316-0.783), and 43.6% versus 13.3% (HR 0.435; 95% CI 0.261-0.727) for the Myriad test. 5yOS was prolonged in the HRD+ subgroup with both tests 67.2% versus 54.4% (HR 0.663; 95% CI 0.442-0.995) for the Leuven test, and 68.0% versus 51.8% (HR 0.596 95% CI 0.393-0.904) for the Myriad test. HRD status was undetermined in 10.7% and 9.4% of the samples, respectively.

CONCLUSIONS

A robust correlation between the Leuven HRD and Myriad test was observed. For HRD+ tumours, the academic Leuven HRD showed a similar difference in PFS and OS as the Myriad test.

Bowel obstruction in advanced tubo-ovarian cancer: a retrospective cohort study

Ten to fifty percent of women with advanced or recurrent ovarian cancer develop malignant bowel obstruction (MBO). We described the management and examined the complications and survival of MBO in primary epithelial tubo-ovarian cancer patients.

Materials and methods

The authors conducted a retrospective monocentric cohort study of tubo-ovarian cancer patients diagnosed with MBO between January 1st, 2011 until August 31st, 2017 at the University Hospitals Leuven, Belgium.

Results

Seventy-three patients with a total of 165 MBO episodes (median 1/patient; range 1-14) were included. The median time interval between cancer diagnosis and first MBO episode was 373 days (range 0-1937). The median time interval between MBO episodes was 44 days (range 6-2004). Complications were bowel perforation (n=5; 7%) and bowel ischemia (n=1; 1%). Conservative treatment was applied in 150 (91%) episodes, including gastrostomy in 4 (2%) episodes and octreotide in 79 (48%) episodes. Surgery was necessary in 15 (9%) episodes. Total parenteral nutrition was administered in 16 (22%) patients. During the study period 62 (85%) patients died (median 167 days since first MBO; range 6-2256). A significant difference in survival was found regarding the tumor marker CA 125 at cancer diagnosis, the use of palliative chemotherapy after the first episode of MBO and palliative surgical treatment for MBO in a group of well selected patients.

Conclusion

Tubo-ovarian cancer patients with MBO have a poor prognosis: 85% of the study population died within a relatively short time interval since the first MBO. In our study population, the majority of patients with MBO were treated conservatively. Both palliative chemotherapy and palliative surgical management are considerable treatment options depending on the individual patient profile.

Influence of Genomic Landscape on Cancer Immunotherapy for Newly Diagnosed Ovarian Cancer: Biomarker Analyses from the IMagyn050 Randomized Clinical Trial

PURPOSE

To explore whether patients with BRCA1/2-mutated or homologous recombination deficient (HRD) ovarian cancers benefitted from atezolizumab in the phase III IMagyn050 (NCT03038100) trial.

PATIENTS AND METHODS

Patients with newly diagnosed ovarian cancer were randomized to either atezolizumab or placebo with standard chemotherapy and bevacizumab. Programmed death-ligand 1 (PD-L1) status of tumor-infiltrating immune cells (IC) was determined centrally (VENTANA SP142 assay). Genomic alterations, including deleterious BRCA1/2 alterations, genomic loss of heterozygosity (gLOH), tumor mutation burden (TMB), and microsatellite instability (MSI), were evaluated using the FoundationOne assay. HRD was defined as gLOH ≥ 16%, regardless of BRCA1/2 mutation status. Potential associations between progression-free survival (PFS) and genomic biomarkers were evaluated using standard correlation analyses and log-rank of Kaplan-Meier estimates.

RESULTS

Among biomarker-evaluable samples, 22% (234/1,050) harbored BRCA1/2 mutations and 46% (446/980) were HRD. Median TMB was low irrespective of BRCA1/2 or HRD. Only 3% (29/1,024) had TMB ≥10 mut/Mb, and 0.3% (3/1,022) were MSI-high. PFS was better in BRCA2-mutated versus BRCA2-non-mutated tumors and in HRD versus proficient tumors. PD-L1 positivity (≥1% expression on ICs) was associated with HRD but not BRCA1/2 mutations. PFS was not improved by adding atezolizumab in BRCA2-mutated or HRD tumors; there was a trend toward enhanced PFS with atezolizumab in BRCA1-mutated tumors.

CONCLUSIONS

Most ovarian tumors have low TMB despite BRCA1/2 mutations or HRD. Neither BRCA1/2 mutation nor HRD predicted enhanced benefit from atezolizumab. This is the first randomized double-blind trial in ovarian cancer demonstrating that genomic instability triggered by BRCA1/2 mutation or HRD is not associated with improved sensitivity to immune checkpoint inhibitors. See related commentary by Al-Rawi et al., p. 1645.

CCNE1 and survival of patients with tubo-ovarian high-grade serous carcinoma: An Ovarian Tumor Tissue Analysis consortium study

BACKGROUND

Cyclin E1 (CCNE1) is a potential predictive marker and therapeutic target in tubo-ovarian high-grade serous carcinoma (HGSC). Smaller studies have revealed unfavorable associations for CCNE1 amplification and CCNE1 overexpression with survival, but to date no large-scale, histotype-specific validation has been performed. The hypothesis was that high-level amplification of CCNE1 and CCNE1 overexpression, as well as a combination of the two, are linked to shorter overall survival in HGSC.

METHODS

Within the Ovarian Tumor Tissue Analysis consortium, amplification status and protein level in 3029 HGSC cases and mRNA expression in 2419 samples were investigated.

RESULTS

High-level amplification (>8 copies by chromogenic in situ hybridization) was found in 8.6% of HGSC and overexpression (>60% with at least 5% demonstrating strong intensity by immunohistochemistry) was found in 22.4%. CCNE1 high-level amplification and overexpression both were linked to shorter overall survival in multivariate survival analysis adjusted for age and stage, with hazard stratification by study (hazard ratio [HR], 1.26; 95% CI, 1.08-1.47, p = .034, and HR, 1.18; 95% CI, 1.05-1.32, p = .015, respectively). This was also true for cases with combined high-level amplification/overexpression (HR, 1.26; 95% CI, 1.09-1.47, p = .033). CCNE1 mRNA expression was not associated with overall survival (HR, 1.00 per 1-SD increase; 95% CI, 0.94-1.06; p = .58). CCNE1 high-level amplification is mutually exclusive with the presence of germline BRCA1/2 pathogenic variants and shows an inverse association to RB1 loss.

CONCLUSION

This study provides large-scale validation that CCNE1 high-level amplification is associated with shorter survival, supporting its utility as a prognostic biomarker in HGSC.

Copy Number Variants Are Ovarian Cancer Risk Alleles at Known and Novel Risk Loci

BACKGROUND

Known risk alleles for epithelial ovarian cancer (EOC) account for approximately 40% of the heritability for EOC. Copy number variants (CNVs) have not been investigated as EOC risk alleles in a large population cohort.

METHODS

Single nucleotide polymorphism array data from 13 071 EOC cases and 17 306 controls of White European ancestry were used to identify CNVs associated with EOC risk using a rare admixture maximum likelihood test for gene burden and a by-probe ratio test. We performed enrichment analysis of CNVs at known EOC risk loci and functional biofeatures in ovarian cancer-related cell types.

RESULTS

We identified statistically significant risk associations with CNVs at known EOC risk genes; BRCA1 (PEOC = 1.60E-21; OREOC = 8.24), RAD51C (Phigh-grade serous ovarian cancer [HGSOC] = 5.5E-4; odds ratio [OR]HGSOC = 5.74 del), and BRCA2 (PHGSOC = 7.0E-4; ORHGSOC = 3.31 deletion). Four suggestive associations (P < .001) were identified for rare CNVs. Risk-associated CNVs were enriched (P < .05) at known EOC risk loci identified by genome-wide association study. Noncoding CNVs were enriched in active promoters and insulators in EOC-related cell types.

CONCLUSIONS

CNVs in BRCA1 have been previously reported in smaller studies, but their observed frequency in this large population-based cohort, along with the CNVs observed at BRCA2 and RAD51C gene loci in EOC cases, suggests that these CNVs are potentially pathogenic and may contribute to the spectrum of disease-causing mutations in these genes. CNVs are likely to occur in a wider set of susceptibility regions, with potential implications for clinical genetic testing and disease prevention.

Real-life data on treatment and outcomes in advanced ovarian cancer: An observational, multinational cohort study (RESPONSE trial)

Background

This study aimed to describe the treatment strategies and outcomes for women with newly diagnosed advanced high‐grade serous or endometrioid ovarian cancer (OC).

Methods

This observational study collected real‐world medical record data from eight Western countries on the diagnostic workup, clinical outcomes, and treatment of adult women with newly diagnosed advanced (Stage III–IV) high‐grade serous or endometrioid OC. Patients were selected backward in time from April 1, 2018 (the index date), with a target of 120 patients set per country, followed for ≥20 months.

Results

Of the 1119 women included, 66.9% had Stage III disease, 11.7% had a deleterious BRCA mutation, and 26.6% received bevacizumab; 40.8% and 39.3% underwent primary debulking surgery (PDS) and interval debulking surgery (IDS), respectively. Of the patients who underwent PDS, 55.5% had no visible residual disease (VRD); 63.9% of the IDS patients had no VRD. According to physician‐assessed responses (at the first assessment after diagnosis and treatment), 53.2% of the total population had a complete response and 25.7% had a partial response to first‐line chemotherapy after surgery. After ≥20 months of follow‐up, 32.9% of the patients were disease‐free, 46.4% had progressive disease, and 20.6% had died. Bevacizumab use had a significant positive effect on overall survival (hazard ratio [HR], 0.62; 95% CI, 0.42–0.91; p = .01). A deleterious BRCA status had a significant positive effect on progression‐free survival (HR, 0.60; 95% CI, 0.41–0.84; p < .01).

Conclusions

Women with advanced high‐grade serous or endometrioid OC have a poor prognosis. Bevacizumab use and a deleterious BRCA status were found to improve survival in this real‐world population.

Lay summary

Patients with advanced (Stage III or IV) ovarian cancer (OC) have a poor prognosis.

The standard treatment options of surgery and chemotherapy extend life beyond diagnosis for 5 years or more in only approximately 45% of patients.

This study was aimed at describing the standard of care in eight Western countries and estimating how many patients who are diagnosed with high‐grade serous or endometrioid OC could potentially be eligible for first‐line poly(adenosine diphosphate ribose) polymerase inhibitor (PARPi) maintenance therapy.

The results highlight the poor prognosis for these patients and suggest that a significant proportion (79%) would potentially be eligible for first‐line PARPi maintenance treatment.

In women diagnosed with high‐grade advanced serous or endometrioid ovarian cancer, bevacizumab use had a significant positive effect on overall survival (hazard ratio [HR], 0.62; 95% CI, 0.42–0.91; p = .01), and a deleterious BRCA status had a significant positive effect on progression‐free survival (HR, 0.60; 95% CI, 0.41–0.84; p < .01). According to clinical responses following surgery and first‐line chemotherapy, almost 8 in 10 women diagnosed with high‐grade advanced serous or endometrioid ovarian cancer would potentially be eligible for first‐line poly(adenosine diphosphate ribose) polymerase inhibitor maintenance treatment.

ENGOT-ov60/GOG-3052/RAMP 201: A phase 2 study of VS-6766 (RAF/MEK clamp) alone and in combination with defactinib (FAK inhibitor) in recurrent low-grade serous ovarian cancer (LGSOC)

TPS5615

Background: Low-grade serous ovarian cancer (LGSOC) constitutes up to 10% of all ovarian cancer and has clinical and molecular characteristics distinct from high-grade serous ovarian cancer. Approximately a third of patients (pts) with recurrent LGSOC harbor KRAS mutations (mt) and pts with KRAS wild-type (wt) LGSOC may have mutations in NRAS, BRAF, or other RAS pathway-associated genes. Prior clinical studies with single agent MEK inhibitors have shown response rates of 16-26% in recurrent LGSOC. VS-6766 is a unique small molecule RAF/MEK clamp that inhibits both RAF and MEK activities by trapping them in inactive complexes. This mechanism of blockade has been shown to limit compensatory MEK activation, thereby potentially enhancing efficacy of MEK inhibition. Focal adhesion kinase (FAK) activation is a putative resistance mechanism to RAF and MEK inhibition, and defactinib, a small molecule inhibitor of FAK, has shown synergistic anti-tumor activity with VS-6766 in preclinical models, including organoids from LGSOC pts. Furthermore, FAK inhibition combined with VS-6766 induces tumor regression in a KRAS mt ovarian cancer xenograft model. The combination of VS-6766 and defactinib is currently being evaluated in the ongoing Investigator Sponsored FRAME study (NCT03875820). In this proof-of-concept study, durable objective responses (ORR = 46%; 11/24) have been reported in recurrent LGSOC pts, including pts who have had a prior MEK inhibitor (Banerjee ESMO 2021) and the combination of VS-6766 + defactinib has received FDA Breakthrough Therapy Designation for recurrent LGSOC. These initial preclinical and clinical results support the ongoing phase 2 ENGOT-ov60/GOG-3052 in recurrent LGSOC. Methods: This is an international phase 2, adaptive, multicenter, randomized, open label study designed to evaluate the efficacy and safety of VS-6766 vs VS-6766 in combination with defactinib currently open to enrollment (NCT04625270). The study will be conducted in two parts. Part A will determine the optimal regimen based on confirmed overall response rate (independent radiology review) in KRAS mt and KRAS wt LGSOC. Part B will determine the efficacy of the optimal regimen identified in Part A in KRAS mt and KRAS wt LGSOC. The minimum expected enrollment is 104 pts, 52 pts with KRAS mt and 52 KRAS wt (64 pts in Part A and 40 pts in Part B). Pts will be randomized to receive VS-6766 (4.0 mg orally (PO), twice weekly 3 wks on, 1 wk off) or VS-6766 with defactinib (VS-6766 3.2 mg PO, twice weekly + defactinib 200 mg PO BID 3 wks on, 1 wk off) till progression. Key inclusion criteria include histologically confirmed LGSOC, known KRAS mutation status, prior systemic therapy including platinum for metastatic disease and up to 1 prior line of MEK inhibitor therapy permitted. Part A of this study has completed enrollment and Part B is currently enrolling pts. Clinical trial information: NCT04625270.

AGO-OVAR 2.29 (ENGOT-ov34): Atezolizumab in combination with bevacizumab and chemotherapy versus bevacizumab and chemotherapy in recurrent ovarian cancer (ROC)

TPS5611

Background: Paclitaxel or pegylated liposomal doxorubicin in combination with bevacizumab constitutes a standard treatment option in patients with relapsed ovarian cancer who are not considered candidate for platinum, but responses are short-lived. Immune checkpoint inhibitors like atezolizumab as single agents have limited activity in ovarian cancer. There is a biologic rationale to combine checkpoint inhibitors with chemotherapy and bevacizumab, however, the role of such combination for the management of ovarian cancer is so far undefined. Because of the intimate relationship between angiogenesis and immunosuppression, it is expected that the inhibition of both pathways could lead to synergism and more durable clinical benefit. The addition of a chemotherapeutic agent is expected to lead to the release of tumor antigens and enhance the efficacy of immunotherapy in turn. Therefore, we aim to test the efficacy of atezolizumab in combination with non-platinum-based chemotherapy and bevacizumab vs the combination of a non-platinum-based chemotherapy and bevacizumab alone. Methods: AGO-OVAR 2.29 is a randomized (1:1), double blinded, phase III trial evaluating the efficacy and safety of atezolizumab plus bevacizumab and chemotherapy (weekly paclitaxel or pegylated liposomal doxorubicin) compared with placebo plus bevacizumab and chemotherapy in patients with recurrent ovarian, fallopian tube, or primary peritoneal cancer with 1st or 2nd relapse within 6 months after completing platinum-based chemotherapy or 3rd relapse. A de novo tumor biopsy to determine the PD-L1 expression status prior to randomization for stratification is mandatory. Patients are treated with chemotherapy plus bevacizumab + atezolizumab/placebo until progression or unacceptable toxicity. Co-primary endpoints are overall survival and progression-free survival. It is planned to randomize approximately 664 patients. Safety interim analyses were performed after inclusion of 24 and an additional 60 and 120 patients who had completed at least one treatment cycle. As of 09th February 2022, 461 patients have been randomized. Clinical trial information: NCT03353831.

Efficacy and safety of lucitanib + nivolumab in patients with advanced gynecologic malignancies: Phase 2 results from the LIO-1 study (NCT04042116; ENGOT-GYN3/AGO/LIO)

5517

Background: LIO-1 is assessing the oral antiangiogenic, multikinase inhibitor lucitanib in combination with the programmed cell death receptor 1 (PD-1) inhibitor nivolumab. Individualized lucitanib dose titration is being explored to maximize lucitanib exposure and potential clinical benefit of the combination. Here, we present data from stage 1 of a Simon 2-stage design across 4 different types of advanced gynecologic cancers from the phase 2 part of LIO-1. Methods: Patients (pts) with advanced, recurrent, or metastatic endometrial cancer (EC, who received ≥1 prior platinum-based chemotherapy); cervical cancer (CC, who received ≥1 prior platinum-based chemotherapy ± bevacizumab); high-grade ovarian cancer (OC, who received ≥2 prior chemotherapies); or EC/OC with clear-cell histology (EOCC, who received ≥1 prior platinum-based chemotherapy + taxane) were enrolled. Prior PD-1 or programmed cell death ligand 1 (PD-L1) inhibitor treatment was excluded, except for up to 10 pts in the EC cohort. Pts received lucitanib at a starting dose of 6 mg once daily (QD), escalating to 8 mg QD and then 10 mg QD if safety-based titration criteria were met, plus intravenous nivolumab 480 mg every 28 days. The data cutoff was Jan 10, 2022. Results: Across cohorts, 100 pts were enrolled to stage 1; 27 (27%) remain on treatment. To date, 28 (28%) have escalated to lucitanib 8 mg, and 17 (17%) have escalated to the maximum dose of 10 mg. Confirmed responses per RECIST v1.1 have been reported in 5/22 (22.7%; 5 partial responses [PRs]) EC pts, 7/22 (31.8%; 2 complete responses [CRs], 5 PRs) CC pts, 4/33 (12.1%; 4 PRs) OC pts, and 5/23 (21.7%; 1 CR, 4 PRs) EOCC pts. Response duration ranges from 1.9+ to 13.1+ months. Of 5 pts with EC who received prior PD-1 inhibitor, there were 2 PRs, and 1 pt with ongoing stable disease of 7+ months. Grade ≥3 treatment-emergent adverse events (TEAEs) considered related to study treatment were reported in 43 (43%) pts, with hypertension the most frequent (n = 25 [25%]). Forty-six (46%) pts had a lucitanib-related TEAE that led to lucitanib interruption and 12 (12%) had one that led to lucitanib dose reduction. Eleven (11%) and 8 (8%) pts discontinued lucitanib and nivolumab, respectively, due to a treatment-related TEAE. Safety results were generally consistent across tumor cohorts. Conclusions: The combination of lucitanib + nivolumab is active in the treatment of advanced gynecological malignancies and has a manageable safety profile through effective dose titration. Stage 2 enrollment has continued in the CC cohort. Biomarker analysis is ongoing, and more mature efficacy and safety data will be presented at the meeting. Clinical trial information: NCT04042116.

Tisotumab vedotin (TV) + pembrolizumab (pembro) in first-line (1L) recurrent or metastatic cervical cancer (r/mCC): Interim results of ENGOT Cx8/GOG 3024/innovaTV 205

5507

Background: TV monotherapy has received US accelerated approval for previously treated r/mCC with disease progression on or after chemotherapy based on clinically meaningful tumor response rate and duration of response (DOR) reported from the GOG-3023/ENGOT-cx6/innovaTV 204 study (Coleman et al., Lancet Onc. 2021). Recently, the recommended phase 2 dose (RP2D) and feasibility of TV + pembro, TV + carboplatin (carbo), and TV + bevacizumab in r/mCC were reported from the dose-escalation phase (Monk et al, IGCS 2021); interim safety and efficacy data from 2 dose-expansion cohorts, 1L TV + carbo and second-line/third-line (2L/3L) TV + pembro (Vergote et al, ESMO 2021) from the ENGOT-cx8/GOG-3024/innovaTV 205 (NCT03786081) study, were also reported. Here we report interim safety and efficacy results from a third dose-expansion cohort evaluating 1L TV + pembro in patients with r/mCC. Methods: Patients with r/mCC who had not received prior systemic therapy (excluding chemoradiation) for r/mCC were treated with the RP2D of TV 2.0 mg/kg + pembro 200 mg intravenously every 3 weeks. The primary endpoint was investigator-assessed confirmed objective response rate (ORR) per RECIST v1.1; secondary endpoints included DOR, progression-free survival (PFS), overall survival (OS), and safety. Results: 33 pts were treated with 1L TV + pembro (median 6 cycles). At data cutoff (July 1, 2021), median duration of exposure to TV + pembro was 5.1 mo (range 1-17) and median follow-up was 12.2 mo (range 1-17). Confirmed ORR among 32 evaluable patients was 41% (95% CI 24-59), with 3 (9%) complete responses and 10 (31%) partial responses. Median time to response was 1.4 mo (range 1.2-2.8); median DOR was not reached, with response ongoing in 7/13 patients. Median PFS was 5.3 mo (95% CI 4.0-12.2); median OS was not reached. The most common treatment-emergent AEs (TEAEs) were alopecia (61%), diarrhea (55%), epistaxis (49%), conjunctivitis (46%), and nausea (46%). Grade ≥3 TEAEs occurred in 67% of patients, the most common being anemia (12%); asthenia (9%); hypokalemia (9%); and increased alanine aminotransferase, decreased white blood cell count, dyspnea, and acute kidney injury (6% each). Three grade 5 TEAEs were reported of which one, disseminated intravascular coagulation, was considered treatment-related. Prespecified AEs of interest (grade 1-2/grade ≥3) with TV included ocular (58%/9%), peripheral neuropathy (45%/3%), and bleeding (61%/6%). Updated results with longer follow-up for this cohort and the 1L TV + carbo and 2L/3L TV + pembro cohorts will be provided at the meeting. Conclusions: TV + pembro demonstrated encouraging, durable antitumor activity with a manageable and acceptable safety profile as a 1L regimen for patients with r/mCC. This trial is ongoing and final analyses will be reported in the future. Clinical trial information: NCT03786081.

Nucleosome footprinting in plasma cell-free DNA for the pre-surgical diagnosis of ovarian cancer

Fragmentation patterns of plasma cell-free DNA (cfDNA) are known to reflect nucleosome positions of cell types contributing to cfDNA. Based on cfDNA fragmentation patterns, the deviation in nucleosome footprints was quantified between diagnosed ovarian cancer patients and healthy individuals. Multinomial modeling was subsequently applied to capture these deviations in a per sample nucleosome footprint score. Validation was performed in 271 cfDNAs pre-surgically collected from women with an adnexal mass. We confirmed that nucleosome scores were elevated in invasive carcinoma patients, but not in patients with benign or borderline disease. Combining nucleosome scores with chromosomal instability scores assessed in the same cfDNA improved prediction of malignancy. Nucleosome scores were, however, more reliable to predict non-high-grade serous ovarian tumors, which are characterized by low chromosomal instability. These data highlight that compared to chromosomal instability, nucleosome footprinting provides a complementary and more generic read-out for pre-surgical diagnosis of invasive disease in women with adnexal masses.

Polygenic risk modeling for prediction of epithelial ovarian cancer risk

Polygenic risk scores (PRS) for epithelial ovarian cancer (EOC) have the potential to improve risk stratification. Joint estimation of Single Nucleotide Polymorphism (SNP) effects in models could improve predictive performance over standard approaches of PRS construction. Here, we implemented computationally efficient, penalized, logistic regression models (lasso, elastic net, stepwise) to individual level genotype data and a Bayesian framework with continuous shrinkage, "select and shrink for summary statistics" (S4), to summary level data for epithelial non-mucinous ovarian cancer risk prediction. We developed the models in a dataset consisting of 23,564 non-mucinous EOC cases and 40,138 controls participating in the Ovarian Cancer Association Consortium (OCAC) and validated the best models in three populations of different ancestries: prospective data from 198,101 women of European ancestries; 7,669 women of East Asian ancestries; 1,072 women of African ancestries, and in 18,915 BRCA1 and 12,337 BRCA2 pathogenic variant carriers of European ancestries. In the external validation data, the model with the strongest association for non-mucinous EOC risk derived from the OCAC model development data was the S4 model (27,240 SNPs) with odds ratios (OR) of 1.38 (95% CI: 1.28-1.48, AUC: 0.588) per unit standard deviation, in women of European ancestries; 1.14 (95% CI: 1.08-1.19, AUC: 0.538) in women of East Asian ancestries; 1.38 (95% CI: 1.21-1.58, AUC: 0.593) in women of African ancestries; hazard ratios of 1.36 (95% CI: 1.29-1.43, AUC: 0.592) in BRCA1 pathogenic variant carriers and 1.49 (95% CI: 1.35-1.64, AUC: 0.624) in BRCA2 pathogenic variant carriers. Incorporation of the S4 PRS in risk prediction models for ovarian cancer may have clinical utility in ovarian cancer prevention programs.

Randomized CLIO/BGOG-ov10 trial of olaparib monotherapy versus physician's choice chemotherapy in relapsed ovarian cancer

OBJECTIVE

Comparison of olaparib (OLA) monotherapy versus chemotherapy in patients with platinum-sensitive (PSOC) or platinum-resistant ovarian cancer (PROC).

METHODS

Patients with measurable disease and ≥ 1 prior line of chemotherapy (CT) were randomized 2:1 to OLA (300 mg tablets, BID) or physician's choice CT.: for PSOC: Carboplatin-Pegylated-Liposomal-Doxorubicin (PLD) or Carboplatin-Gemcitabine; for PROC: PLD, Topotecan, Paclitaxel or Gemcitabine.

RESULTS

160 patients (60 with PSOC and 100 with PROC) were randomized 2:1 to OLA (n = 107) or CT (n = 53). Baseline characteristics were similar between both arms. Overall objective response rate (ORR) for OLA and CT were similar (24.3% (26/107) and 28.3% (15/53), respectively). Clinical benefit rate (≥ 12 weeks) was similar with 54.2% (58/107) and 56.6% (30/53), respectively. In PSOC, ORR was 35.0% (14/40) and 65.0% (13/20) for OLA and CT (p = 0.053); in PROC, ORR was 17.9% (12/67) and 6.1% (2/33) for OLA and CT (p = 0.134). ORR in heavily pretreated PROC (>4 prior lines) was 22.9% (8/35) with OLA versus 0% (0/14) for CT. ORR of 35.7% (5/14) and 13.2% (7/53) was observed in BRCA-mutated and -wildtype PROC cases, respectively. Median PFS in PROC was not significantly different with 2.9 months (95% CI 2.8-5.1 in the OLA group versus 3.8 months (95% CI 3.0-6.4) in the CT group (hazard ratio [HR] 1.11 [95% CI 0.72-1.78]; log-rank p = 0.600).

CONCLUSION

OLA monotherapy showed overall an equal response rate in relapsed ovarian cancer compared with CT. In PROC, ORR and TFST tended to be higher with OLA than with CT. In heavily pretreated patients (four lines or more) with PROC disease, OLA treatment seemed to be more effective than CT.

Prospective non-interventional BELOVA/BGOG-ov16 study on safety of frontline bevacizumab in elderly patients with FIGO stage IV ovarian cancer: a study of the Belgian and Luxembourg Gynaecological Oncology Group

Objective

Because elderly patients with ovarian cancer are underrepresented in randomized studies, this study aimed to expand our knowledge on the safety and effectiveness of frontline treatment with bevacizumab in combination with standard carboplatin and paclitaxel chemotherapy in patients aged 70 years and older with a diagnosis of Federation of Gynecology and Obstetrics (FIGO) stage IV ovarian cancer in routine clinical practice in Belgium.

Methods

Patients aged 70 years and older with FIGO stage IV ovarian cancer were included in a multicenter, non-interventional prospective study

to evaluate the safety and effectiveness of treatment with bevacizumab in combination with frontline carboplatin and paclitaxel chemotherapy. Comprehensive geriatric assessments were performed at baseline and during treatment.

Results

The most frequently reported adverse events for bevacizumab were hypertension (55%), epistaxis (32%) and proteinuria (21%). The Kaplan-Meier estimate of progression-free survival was 14.5 months. The results of the comprehensive geriatric assessments during treatment indicated a slight improvement in the geriatric eight health status screening tool score for general health status and the mini-nutritional assessment score for nutritional status. The median change from baseline score was close to zero for the instruments measuring independency, activity of daily living and instrumental activities of daily living, and for the mobility-tiredness test measuring self-perceived fatigue.

Conclusions

No new safety signals were registered in this study in patients aged 70 years and older treated with bevacizumab and frontline carboplatin and paclitaxel for FIGO stage IV ovarian cancer. Elderly patients should not be excluded from treatment for advanced ovarian cancer based on age alone.

EU PAS register

ENCEPP/SDPP/13849.

ClinicalTrials.gov identifier

NCT02393898.

Abstract P046: ENGOT-ov60/GOG3052/RAMP 201: A phase 2 study of VS-6766 (dual RAF/MEK inhibitor) alone and in combination with defactinib (FAK inhibitor) in recurrent low-grade serous ovarian cancer (LGSOC)

Background: VS-6766 is a unique small molecule inhibitor that blocks MEK kinase activity and RAF phosphorylation of MEK. This mechanism of blockade has been shown to limit compensatory MEK activation, thereby potentially enhancing efficacy of MEK inhibition. Defactinib, (VS-6063), an orally active small molecule, is a potent adenosine 5'- triphosphate (ATP) competitive, reversible inhibitor of focal adhesion kinase (FAK). Defactinib has shown synergistic activity with BRAF and MEK inhibitors in both in vitro and in vivo solid tumor models. Prior molecularly unselected studies with single agent MEK inhibitors have shown response rates up to 26% in recurrent LGSOC. A third of patients with recurrent LGSOC harbor somatic KRAS mutations. FAK inhibition has been shown to induce tumor regression when combined with RAF, MEK or RAF/MEK inhibitors in in vivo models of KRAS mutant ovarian cancer. The combination of VS-6766 and defactinib is currently being evaluated in the ongoing Investigator Sponsored FRAME study (NCT03875820). In this proof of concept study, durable objective responses have been reported in recurrent LGSOC patients, particularly those with KRAS mutations including patients who have had a prior MEK inhibitor (Banerji et al AACR 2020). Based on preclinical studies demonstrating efficacy of both VS-6766 and the VS-6766/defactinib combination and preliminary results of the FRAME study, the phase II ENGOT-ov60/GOG3052 has been developed in recurrent LGSOC. Methods: This is a Phase II, adaptive, two-part, multicenter, parallel cohort, randomized, open label study designed to evaluate the efficacy and safety of VS-6766 versus VS-6766 in combination with defactinib (NCT04625270). The study will be conducted in two parts. Part A will determine the optimal regimen based on confirmed overall response rate (independent radiology review) in KRAS-mutated LGSOC. Part B will determine the efficacy of the optimal regimen identified in Part A in KRAS-mutated and KRAS wild-type LGSOC. The minimum expected enrollment is 52 subjects with KRAS-mutated tumors (32 subjects in Part A and 20 in Part B) and 36 with KRAS wild-type tumors in Part B. Patients will be randomized to receive VS-6766 (4.0 mg PO, twice weekly 3 weeks on, 1 week off) or VS6766 with defactinib (VS-6766 3.2 mg PO, twice weekly + defactinib 200 mg PO BID 3 weeks on, 1 week off) till progression. Key inclusion criteria include histologically confirmed LGSOC, presence of KRAS mutation (Part A), prior systemic therapy for metastatic disease and up to 1 prior line of MEK/RAF inhibitor therapy permitted. This international study is open to enrollment.

Citation Format: Susana N. Banerjee, Bradley J. Monk, Els Van Nieuwenhuysen, Kathleen N. Moore, Ana Oaknin, Michel Fabbro, Nicoletta Columbo, David M. O’Malley, Robert L. Coleman, Jonathan Pachter, Andrew Koustenis, Gloria Patrick, Lorna Leonard, Rachel Grisham. ENGOT-ov60/GOG3052/RAMP 201: A phase 2 study of VS-6766 (dual RAF/MEK inhibitor) alone and in combination with defactinib (FAK inhibitor) in recurrent low-grade serous ovarian cancer (LGSOC) [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P046.

Immunotherapy in rare ovarian cancer

PURPOSE OF REVIEW

Ovarian cancer (OC) is a heterogeneous disease and a mounting body of evidence shows that a 'one-size-fits-all' approach is obsolete. Differences in epidemiology, tumor biology, genetic profiles and treatment responses of these different types necessitate a tumor and patient-specific approach. Ninety percentage consists of epithelial OC with 70% being high-grade serous OC. The other rarer subtypes are low-grade serous (5%), clear cell (12%), endometrioid (11%) and mucinous carcinoma (3%). The remaining 10% are nonepithelial rare OCs: germ cell (3%) and sex-cord stromal tumors (7%).

RECENT FINDINGS

Over the past few decades, the 5-year survival rates have only improved modestly, therefore novel therapies are urgently needed. Recently, immunotherapy has been introduced into clinical practice in a number of solid tumors. Although preclinical data confirm the presence of an immunogenic microenvironment in a number of ovarian tumor types, no single-agent immune checkpoint inhibitor has been approved hitherto. Identifying suitable treatment combinations, adequate patient selection and thus correct implementation of immunotherapy remain major challenges.

SUMMARY

In this review, we focus on the rationale of incorporating immune therapy in rare OC, we summarize the recent developments with preclinical data and results of clinical trials, with particular focus on rare ovarian histological subtypes.

Comprehensive immunomolecular profiling of endometrial carcinoma: A tertiary retrospective study

OBJECTIVE

Combined immunohistochemical and molecular classification using the Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) independently predicts prognosis in endometrial carcinoma (EC). As next-generation sequencing (NGS) is entering clinical practice, we evaluated whether more comprehensive immunomolecular profiling (CIMP), including NGS and extended immunohistochemical analysis, could further refine the current ProMisE classification.

METHODS

A series of 120 consecutive ECs, classified according to ProMisE, was stained immunohistochemically for CD3, CD8, PD-L1, beta-catenin and L1CAM. An in-house 96 gene NGS panel was performed on a subset of 44 ECs, representing the 4 ProMisE subgroups (DNA polymerase epsilon catalytic subunit exonuclease domain mutated (POLEmut), mismatch repair deficient (MMRd), p53 abnormal (p53 abn) and no specific molecular profile (NSMP) ECs). Cases harboring non-hotspot POLE variants were analyzed with Illumina TruSight Oncology 500 NGS panel (TSO500) as a surrogate for whole-exome sequencing.

RESULTS

Eight cases harbored POLE variants, half of which were hotspots. Using TSO500, non-hotspot POLE variants were classified as pathogenic (3) or variant of unknown significance (1). POLEmut and MMRd ECs typically showed higher numbers of CD3⁺/CD8⁺ tumor-infiltrating lymphocytes and higher PD-L1 expression in tumor-infiltrating immune cells. p53 abn ECs showed significantly higher L1CAM immunoreactivity and frequently harbored gene amplifications including HER2 (25%), but typically lacked ARID1A or PTEN variants. Beta-catenin-positivity and FGFR2 variants were predominantly found in NSMP ECs.

CONCLUSIONS

Our data show that CIMP adds significant value to EC characterization and may help to determine pathogenicity of non-hotspot POLE variants, encountered more frequently than expected in our series. In addition, CIMP may reveal ECs benefitting from immune checkpoint inhibition and allows upfront identification of targetable alterations, such as HER2 amplification in p53 abn ECs.

High-grade serous tubo-ovarian cancer refined with single-cell RNA sequencing: specific cell subtypes influence survival and determine molecular subtype classification

BACKGROUND

High-grade serous tubo-ovarian cancer (HGSTOC) is characterised by extensive inter- and intratumour heterogeneity, resulting in persistent therapeutic resistance and poor disease outcome. Molecular subtype classification based on bulk RNA sequencing facilitates a more accurate characterisation of this heterogeneity, but the lack of strong prognostic or predictive correlations with these subtypes currently hinders their clinical implementation. Stromal admixture profoundly affects the prognostic impact of the molecular subtypes, but the contribution of stromal cells to each subtype has poorly been characterised. Increasing the transcriptomic resolution of the molecular subtypes based on single-cell RNA sequencing (scRNA-seq) may provide insights in the prognostic and predictive relevance of these subtypes.

METHODS

We performed scRNA-seq of 18,403 cells unbiasedly collected from 7 treatment-naive HGSTOC tumours. For each phenotypic cluster of tumour or stromal cells, we identified specific transcriptomic markers. We explored which phenotypic clusters correlated with overall survival based on expression of these transcriptomic markers in microarray data of 1467 tumours. By evaluating molecular subtype signatures in single cells, we assessed to what extent a phenotypic cluster of tumour or stromal cells contributes to each molecular subtype.

RESULTS

We identified 11 cancer and 32 stromal cell phenotypes in HGSTOC tumours. Of these, the relative frequency of myofibroblasts, TGF-β-driven cancer-associated fibroblasts, mesothelial cells and lymphatic endothelial cells predicted poor outcome, while plasma cells correlated with more favourable outcome. Moreover, we identified a clear cell-like transcriptomic signature in cancer cells, which correlated with worse overall survival in HGSTOC patients. Stromal cell phenotypes differed substantially between molecular subtypes. For instance, the mesenchymal, immunoreactive and differentiated signatures were characterised by specific fibroblast, immune cell and myofibroblast/mesothelial cell phenotypes, respectively. Cell phenotypes correlating with poor outcome were enriched in molecular subtypes associated with poor outcome.

CONCLUSIONS

We used scRNA-seq to identify stromal cell phenotypes predicting overall survival in HGSTOC patients. These stromal features explain the association of the molecular subtypes with outcome but also the latter's weakness of clinical implementation. Stratifying patients based on marker genes specific for these phenotypes represents a promising approach to predict prognosis or response to therapy.

Cause of death for patients with breast cancer: discordance between death certificates and medical files, and impact on survival estimates

BACKGROUND

Registration and coding of cause of death is prone to error since determining the exact underlying condition leading directly to death is challenging. In this study, causes of death from the death certificates were compared to patients' medical files interpreted by experts at University Hospitals Leuven (UHL), to assess concordance between sources and its impact on cancer survival assessment.

METHODS

Breast cancer patients treated at UHL (2009-2014) (follow-up until December 31st 2016) were included in this study. Cause of death was obtained from death certificates and expert-reviewed medical files at UHL. Agreement was calculated using Cohen's kappa coefficient. Cause-specific survival (CSS) was calculated using the Kaplan-Meier method and the relative survival probability (RS) using the Ederer II and Pohar Perme method.

RESULTS

A total of 2862 patients, of whom 354 died, were included. We found an agreement of 84.7% (kappa-value of 0.69 (95% C.I.: 0.62-0.77)) between death certificates and medical files. Death certificates had 10.7% false positive and 4.5% false negative rates. However, five-year CSS and RS measures were comparable for both sources.

CONCLUSION

For breast cancer patients included in our study, fair agreement of cause of death was seen between death certificates and medical files with similar CSS and RS estimations.

Tisotumab vedotin versus investigator’s choice chemotherapy in second- or third-line recurrent or metastatic cervical cancer (innovaTV 301/ENGOT-cx12/GOG 3057, trial in progress)

TPS5596

Background: Doublet chemotherapy (paclitaxel plus either platinum or topotecan) with bevacizumab (if eligible) is recommended for first-line treatment of recurrent (not amenable to curative therapy) or metastatic cervical cancer (r/mCC; Tewari 2014). In the second-line setting, there are limited data for currently available treatment options. Tisotumab vedotin (TV) is an investigational antibody-drug conjugate (ADC) composed of a tissue factor (TF)-directed human monoclonal antibody covalently linked to the microtubule-disrupting agent monomethyl auristatin E (MMAE) via a protease-cleavable linker. TV is directed to cells expressing TF and releases MMAE upon internalization, resulting in cell cycle arrest and apoptotic cell death. TV has anti-tumor activity on multiple tumor types and kills tumor cells by direct cytotoxicity, bystander cytotoxicity, antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis, and in a manner consistent with immunogenic cell death. In a recent phase 2 pivotal trial (innovaTV 204), TV demonstrated a clinically meaningful objective response rate (ORR) of 24% and median duration of response (DOR) of 8.3 months, as well as a manageable and tolerable safety profile with most adverse events being mild to moderate, in r/mCC patients with disease progression on or after chemotherapy. These findings support further investigation of TV in patients with r/mCC who progress on available first-line treatment options. Methods: The innovaTV 301 trial (NCT04697628) is a global, randomized, open-label, phase 3 clinical trial evaluating the efficacy and safety of TV in patients with previously treated r/mCC. Eligible patients must be ≥18 years, have r/mCC, and have experienced disease progression after receiving 1-2 prior lines of therapy (either standard of care systemic chemotherapy doublet or platinum-based therapy [if eligible; paclitaxel+cisplatin+bevacizumab, paclitaxel+carboplatin+bevacizumab, or paclitaxel+topotecan/nogitecan+bevacizumab]). Approximately 482 patients will be randomized 1:1 to receive 21-day cycles of either TV (2.0 mg/kg IV once every 3 weeks) or investigator’s choice of chemotherapy: topotecan (1 or 1.25 mg/m2 IV; Day 1 [D1] to D5 of each cycle), vinorelbine (30 mg/m2 IV; D1 and D8 of each cycle), gemcitabine (1000 mg/m2 IV; D1 and D8 of each cycle), irinotecan (100 or 125 mg/m2 IV; weekly for 28days, then every 42 days), or pemetrexed (500 mg/m2 IV, D1 of each cycle). The primary endpoint of this trial is overall survival. Key secondary endpoints are progression-free survival, ORR, time to response, DOR, safety, and quality of life outcomes. The study is currently enrolling and will have sites open in the US, EU, Japan, Latin America, Taiwan, Singapore, and South Korea. Clinical trial information: NCT04697628.

ENGOT-ov60/GOG3052/RAMP 201: A phase 2 study of VS-6766 (dual RAF/MEK inhibitor) alone and in combination with defactinib (FAK inhibitor) in recurrent low-grade serous ovarian cancer (LGSOC)

TPS5603

Background: VS-6766 is a unique small molecule inhibitor that blocks MEK kinase activity and RAF phosphorylation of MEK. This mechanism of blockade has been shown to limit compensatory MEK activation, thereby potentially enhancing efficacy of MEK inhibition. Defactinib, (VS-6063), an orally active small molecule, is a potent adenosine 5'- triphosphate (ATP) competitive, reversible inhibitor of focal adhesion kinase (FAK). Defactinib has shown synergistic activity with BRAF and MEK inhibitors in both in vitro and in vivo solid tumor models. Prior molecularly unselected studies with single agent MEK inhibitors have shown response rates up to 26% in recurrent LGSOC. A third of patients with recurrent LGSOC harbor somatic KRAS mutations. FAK inhibition has been shown to induce tumor regression when combined with RAF, MEK or RAF/MEK inhibitors in in vivo models of KRAS mutant ovarian cancer. The combination of VS-6766 and defactinib is currently being evaluated in the ongoing Investigator Sponsored FRAME study (NCT03875820). In this proof of concept study, durable objective responses have been reported in recurrent LGSOC patients, particularly those with KRAS mutations including patients who have had a prior MEK inhibitor (Banerji et al AACR 2020). Based on preclinical studies demonstrating efficacy of both VS-6766 and the VS-6766/defactinib combination and preliminary results of the FRAME study, the phase II ENGOT-ov60/GOG3052 has been developed in recurrent LGSOC. Methods: This is a Phase II, adaptive, two-part, multicenter, parallel cohort, randomized, open label study designed to evaluate the efficacy and safety of VS-6766 versus VS-6766 in combination with defactinib (NCT04625270). The study will be conducted in two parts. Part A will determine the optimal regimen based on confirmed overall response rate (independent radiology review) in KRAS-mutated LGSOC. Part B will determine the efficacy of the optimal regimen identified in Part A in KRAS-mutated and KRAS wild-type LGSOC. The minimum expected enrollment is 52 subjects with KRAS-mutated tumors (32 subjects in Part A and 20 in Part B) and 36 with KRAS wild-type tumors in Part B. Patients will be randomized to receive VS-6766 (4.0 mg PO, twice weekly 3 weeks on, 1 week off) or VS6766 with defactinib (VS-6766 3.2 mg PO, twice weekly + defactinib 200 mg PO BID 3 weeks on, 1 week off) till progression. Key inclusion criteria include histologically confirmed LGSOC, presence of KRAS mutation (Part A), prior systemic therapy for metastatic disease and up to 1 prior line of MEK/RAF inhibitor therapy permitted. This international study is open to enrollment. Clinical trial information: NCT04625270.

Combination of weekly paclitaxel-carboplatin plus standard bevacizumab as neoadjuvant treatment in stage IB-IIB cervical cancer

OBJECTIVE

In this study we investigated response rates of bevacizumab in addition to weekly paclitaxel and carboplatin in neoadjuvant setting in cervical cancer stage IB-IIB.

METHODS

In this retrospective study we included patients with FIGO 2018 stage IB-IIB cervical cancer. Treatment consisted of 9 weeks' neoadjuvant paclitaxel and carboplatin (paclitaxel 60 mg/m², carboplatin AUC 2.7; both weekly) and bevacizumab (15 mg/kg every 3 weeks). The radiologic response rate was analyzed using the Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 criteria. The definition of optimal pathological response was complete disappearance of tumor (complete response, pCR) or residual disease with less than 3 mm stromal invasion (pPR1). Suboptimal pathologic response (pPR2) was defined as persistent residual disease with more than 3 mm stromal invasion.

RESULTS

A total of 30 patients were included. Six patients had FIGO 2018 stage IB1-IB2 (20%), one had stage IB3 (3%), five had stage IIA (17%), and 18 had stage IIB (60%). After completing the neoadjuvant chemotherapy, all patients showed a RECIST response (seven (23%) complete response; 23 (77%) partial response). Six patients (20%) were judged to be still inoperable. After radical hysterectomy, optimal pathological response was observed in 11 patients (38%) (pCR in nine patients (29%) and pPR1 in two patients (8%)). Six patients (20%) received postoperative adjuvant chemoradiotherapy. Hematological toxicity was similar to neoadjuvant weekly paclitaxel and carboplatin, as we reported earlier. Grade IV proteinuria or hypertension was not observed and no administration of bevacizumab was delayed or dose-reduced.

CONCLUSION

Bevacizumab in addition to weekly paclitaxel and carboplatin showed a 100% radiological RECIST response and an optimal pathological response of 38%. Although bevacizumab has an established role in the treatment of recurrent cervical cancer in combination with paclitaxel and carboplatin, we did not observe a tendency toward superior effect on the pathological response rate of bevacizumab in the neoadjuvant chemotherapy setting.

Abstract PS7-63: Cause of death discordance between death certificates and medical files: Impact on cancer survival assessment in a Belgian case study

Introduction Accurate information on cause of death is essential for correct breast cancer-specific mortality assessment. However, registration and coding of cause of death is prone to error since determining the exact underlying condition related to the death is challenging. In this study, an expert review of medical files was done to determine the principal cause of death for breast cancer patients of a Belgian tertiary hospital. The retrieved cause of death was compared to death certificate information to assess concordance between both sources. Secondly, the impact of discordant reporting on cause-specific survival (CSS) and other net survival approaches were examined. Methods Breast cancer patients diagnosed and treated at University Hospitals Leuven (UHL) between 2009 and 2014 with follow-up until December 31st, 2016, were included in the study. Information on cause of death was obtained from death certificates (following ICD-10 rules) and medical files. The latter were reviewed by a board of experts at UHL. Agreement was calculated using Cohen’s kappa coefficient, and reasons for discordant reporting were assessed. CSS was calculated based on cause of death information from both sources using the Kaplan-Meier method. These survival estimates were compared to the relative survival probability (RS) using the Ederer II and Pohar Perme method. Results A total of 2,862 patients were included, of whom 354 died after a median follow-up of 54.6 months. We found overall substantial agreement (kappa-value of 0.69 (95% C.I.: 0.62-0.77)) between cause of death reported by death certificates and medical files (Table 1). In 84.8% of cases, there was concordance between both methods. When comparing to medical files, misattribution of breast cancer-specific death in death certificates (4.5% of cases) was linked to the presence of comorbidities (43.7%), metastases (37.5%), or unspecified causes (18.8%). Five-year CSS based on medical files (93.1% (95% C.I.: 91.9-94.1)) was only slightly higher compared to CSS based on death certificates (92.3% (95% C.I.: 91.2-93.4)). RS measures using Ederer II and Pohar Perme were comparable to CSS measures. Conclusions Overall, substantial agreement of cause of death was seen between death certificates and medical files. Attribution of cause death to comorbidities was the most common reason for discordant reporting of breast cancer-specific death. Five-year breast cancer-specific survival was slightly higher based on cause of death information from medical files, compared to death certificates. Periodic reviews and implementation of ICD-10 guidelines for classification of cause of death could improve accuracy in cause of death annotation.

Table 1: Discordance for the principal cause of death between medical files and death certificatesmedical filesother causesbreast cancerdeath certificatesother causes136 (38.4%)16 (4.5%)152 (42.9%)breast cancer38 (10.7%)164 (46.3%)202 (57.1%)174 (49.2%)180 (50.9%)354 (100%)

Citation Format: Hava Izci, Tim Tambuyzer, Jessica Vandeven, Jérôme Xicluna, Hans Wildiers, Kevin Punie, Nynke Willers, Eva Oldenburger, Els Van Nieuwenhuysen, Patrick Berteloot, Ann Smeets, Ines Nevelsteen, Liesbet Van Eycken, Harlinde De Schutter, Patrick Neven, Geert Silversmit, Freija Verdoodt. Cause of death discordance between death certificates and medical files: Impact on cancer survival assessment in a Belgian case study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-63.

Impact of clinical factors and surgical outcome on long-term survival in high-grade serous ovarian cancer: a multicenter analysis

INTRODUCTION

Long-term survivors of ovarian cancer are a unique group of patients in whom prognostic factors for long-term survival have been poorly described. Such factors may provide information for a more personalized therapeutic approach. The objective of this study is to determine further characteristics of long-term survivors with high-grade serous ovarian cancer.

METHODS

Long-term survivors were defined as patients living longer than 8 years after first diagnosis and were recruited within seven high volume centers across Europe from November 1988 to November 2008. The control group included patients with high-grade serous ovarian cancer with less than 5 years' survival identified from the systematic 'Tumorbank ovarian cancer' database. A subanalysis of Charité patients only was performed separately for in-depth analysis of tumor dissemination. Propensity score matching with nearest-neighbor caliper width was used to match long-term survivors and the control group regarding age, FIGO stage, and residual tumor.

RESULTS

A total of 276 patients with high-grade serous ovarian cancer were included, divided into 131 long-term survivors and 145 control group patients. After propensity score matching and multivariable adjustment, platinum sensitivity (p=0.002) was an independent favorable prognostic factor whereas recurrence (p<0.001) and ascites (p=0.021) were independent detrimental predictors for long-term survival. Significantly more long-term survivors tested positive for mutation in the BRCA1 gene than the BRCA2 gene (p=0.016). Intraoperatively, these patients had less tumor involvement of the upper abdomen at initial surgery (p=0.024). Complexity of surgery and surgical techniques were similar in both cohorts.

CONCLUSION

Platinum sensitivity constitutes a favorable factor for long-term survival whereas tumor involvement of the upper abdomen, ascites, and recurrence have a negative impact. Based on clinical estimation, long-term survival is associated with combinations of clinical, surgical, and molecular factors.

Experience with PlasmaJet™ in debulking surgery in 87 patients with advanced-stage ovarian cancer

OBJECTIVE

The aim was to evaluate the effectiveness and safety of PlasmaJet™ in cytoreductive surgery in patients with advanced-stage ovarian cancer.

METHODS

All patients between September 2013 and January 2018 undergoing surgical cytoreduction for advanced-stage ovarian cancer with the help of PlasmaJet™ were identified and analyzed retrospectively.

RESULTS

Eighty-seven patients diagnosed with advanced-stage ovarian cancer underwent surgery with PlasmaJet™. Primary debulking surgery was performed in 15 cases. Fifty-seven patients underwent interval debulking after neoadjuvant chemotherapy. Secondary and tertiary debulking was done in, respectively, 11 and three patients, and one patient underwent quaternary debulking using PlasmaJet™. In all 87 patients but one, complete resection of all macroscopic disease was obtained. PlasmaJet™ was used to remove carcinomatosis on the peritoneum, bowel serosa, intestinal mesentery, and lesions in the upper abdomen (diaphragm and liver surface). No damage to the bladder or ureter was noted in relation to the use of PlasmaJet™. Three patients developed a bowel leakage postoperatively. In one of these patients, PlasmaJet™ was used to treat tumoral implants in the affected region.

CONCLUSIONS

Our series suggests that the use of PlasmaJet™ is efficient and safe in obtaining complete resection of all macroscopic tumoral lesions in advanced-stage ovarian cancer.

Atezolizumab in combination with bevacizumab and chemotherapy versus bevacizumab and chemotherapy in recurrent ovarian cancer - a randomized phase III trial (AGO-OVAR 2.29/ENGOT-ov34)

BACKGROUND

Improvement in clinical outcomes of patients with platinum-resistant disease is an unmet medical need and trials in this population are urgently needed. Checkpoint-inhibitors have already shown activity in multiple other tumor entities and ovarian cancer, especially in the combination with anti-angiogenic treatment.

PRIMARY OBJECTIVE

To test if the activity of non-platinum-based chemotherapy and bevacizumab could be improved by the addition of atezolizumab.

STUDY HYPOTHESIS

The addition of atezolizumab to standard non-platinum combination of chemotherapy and bevacizumab improves median overall survival from 15 to 20 months.

TRIAL DESIGN

Patients are randomized to chemotherapy (paclitaxel weekly or pegylated liposomal doxorubicin) + bevacizumab + placebo vs chemotherapy + bevacizumab + atezolizumab. Stratification factors are: number of prior lines, planned type of chemotherapy, prior use of bevacizumab, and tumor programmed death-ligand 1 (PD-L1) status.

MAJOR INCLUSION/EXCLUSION CRITERIA

Recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer with up to three prior therapies and a treatment-free interval after platinum of less than 6 months. Patients with three prior lines of chemotherapy are eligible irrespective of the platinum free-interval. A de novo tumor tissue sample biopsy for determination of PD-L1 status prior to randomization for stratification is mandatory. Major exclusion criteria consider bevacizumab-specific and immunotherapy-specific criteria.

PRIMARY ENDPOINT

Overall survival and progression-free survival are co-primary endpoints.

SAMPLE SIZE

It is planned to randomize 664 patients.

TRIAL REGISTRATION

NCT03353831.

Cancer Surveillance in Healthy Carriers of Germline Pathogenic Variants in BRCA1/2: A Review of Secondary Prevention Guidelines

Germline pathogenic alterations in the breast cancer susceptibility genes 1 (BRCA1) and 2 (BRCA2) are the most prevalent causes of hereditary breast and ovarian cancer. The increasing trend in proportion of cancer patients undergoing genetic testing, followed by predictive testing in families of new index patients, results in a significant increase of healthy germline BRCA1/2 mutation carriers who are at increased risk for breast, ovarian, and other BRCA-related cancers. This review aims to give an overview of available screening guidelines for female and male carriers of pathogenic or likely pathogenic germline BRCA1/2 variants per cancer type, incorporating malignancies that are more or less recently well correlated with BRCA1/2. We selected guidelines from national/international organizations and/or professional associations that were published or updated between January 1, 2015, and February 1, 2020. In total, 12 guidelines were included. This review reveals several significant discordances between the different guidelines. Optimal surveillance strategies depend on accurate age-specific cancer risk estimates, which are not reliably available for all BRCA-related cancers. Up-to-date national or international consensus guidelines are of utmost importance to harmonize counseling and proposed surveillance strategies for BRCA1/2 carriers.

Fatigue in long-term survivors with ovarian cancer: Results of Expression VI – Carolin meets HANNA – Holistic analysis of Long-term survival with ovarian cancer—The international NOGGO, ENGOT and GCIG survey

12065

Background: Long-term survivors (LTS) with ovarian cancer may be cured from cancer but frequently experience long-term toxicities such as fatigue with a huge impact on quality of life. Aim of this study was to evaluate factors associated with fatigue in LTS. Methods: Within the study “Carolin meets HANNA” ( www.carolinmeetshanna.com ) long-term survivors with ovarian cancer (LTS) were recruited since 11/2016. Long-term survival was defined as an ovarian cancer diagnosis more than eight years ago. Results: Until 12/2019 473 LTS could be recruited. 211 LTS (44.5%) have experienced fatigue. At the time point of recruitment in 23.4% (111 LTS) fatigue was still present. LTS with fatigue were not more frequently under current treatment compared to LTS without fatigue (p = 0.348). LTS with fatigue were not younger at initial diagnosis (50.4 vs. 51.9 years, p = 0.228). 58.6% of LTS with fatigue compared to 41.5% without fatigue have developed recurrent disease (p = 0.002) and LTS had more frequently more than one recurrence (66.1% vs. 51.7%, p = 0.055). Fatigue was associated with worse health status (2.9 vs. 2.2 on a scale from 1-5, p < 0.001). Fatigue was associated with medical complaints in general (82.0% vs. 43.0%, p < 0.001). Symptoms such as nausea and vomiting (p < 0.001), loss of appetite (p < 0.001), constipation (p < 0.001), diarrhea (p < 0.001), weight loss (p = 0.001) and bloating (p < 0.001) were more frequent in LTS with fatigue. This also accounts for cognitive disorders (39.6% vs. 10.5%, p < 0.001), depression (23.4% vs. 7.4%, p < 0.001), polyneuropathy (39.6% vs. 13.2%, p < 0.001) and cardiovascular disease (11.7% vs. 3.6%, p = 0.002). LTS with fatigue regard themselves more frequently as cancer patient (73.9% vs. 40.8%), p < 0.001). Conclusions: Fatigue is still very common in LTS despite the long survival time. Fatigue is associated with worsened health status and other long-term side effects underlining the impact on LTS. There is a high need for survivorship clinics that should ask for and, if necessary, should address still existing side effects such as fatigue.

DUO-E/GOG-3041/ENGOT-EN10: a randomized phase III trial of first-line carboplatin (carb) and paclitaxel (pac) in combination with durvalumab (durva), followed by maintenance durva with or without olaparib (ola), in patients (pts) with newly diagnosed (nd) advanced or recurrent endometrial cancer (EC)

TPS6108

Background: There is a high unmet need for advances in EC treatment that provide progression-free survival (PFS) and overall survival (OS) benefits. EC tumors are sensitive to carb/pac (Pectasides et al. Gynecol Oncol 2008). Maintenance therapy with the poly(ADP-ribose) polymerase inhibitor (PARPi) ola (with or without bevacizumab) led to significant PFS benefits in advanced ovarian cancer pts with either nd (SOLO1, Moore et al. NEJM 2018; PAOLA-1, Ray-Coquard et al. NEJM 2019) or recurrent (SOLO2, Pujade-Lauraine et al. Lancet Oncol 2017; Study 19, Friedlander et al. Br J Cancer 2018) platinum-sensitive disease, regardless of BRCA mutation status (PAOLA-1; Study 19), and in BRCA-mutated metastatic pancreatic cancer pts (POLO, Golan et al. NEJM 2019). Molecular features of EC could predict sensitivity to PARPi (de Jonge et al. Clin Cancer Res 2019; Auguste et al. Mod Pathol 2018). PARPi has been shown to prime the immune microenvironment in a preclinical BRCA1 mutant ovarian model (Higuchi et al. Cancer Immunol Res 2015). Clinical trials have demonstrated antitumor activity of the anti-programmed cell death ligand-1 (anti-PD-L1) blocker durva (Antill et al. J Clin Oncol 2019) and anti-programmed cell death-1 (anti-PD-1) antibody therapies (Makker et al. ESMO 2019; Oaknin et al. SGO 2019) in EC pts. The DUO-E trial (EUDRACT 2019-004112-60, D9311C00001, NCT04269200) will investigate whether the addition of durva to carb/pac, followed by durva (with or without ola) maintenance treatment, improves PFS in pts with nd advanced or recurrent EC. Methods: Eligible pts for this multicenter, double-blind, Phase III trial must have nd Stage III/IV or recurrent EC and be naïve to first-line chemotherapy. Pts will be randomized (1:1:1; n=~233 per arm) to: arm A) carb/pac + placebo (pbo) (q3w for six cycles) followed by pbo maintenance treatment; arm B) carb/pac + durva (1120 mg; q3w for six cycles) followed by maintenance treatment with durva (1500 mg q4w) + pbo (tablets bid); or arm C) carb/pac + durva (1120 mg; q3w for six cycles) followed by maintenance treatment with durva (1500 mg q4w) + ola (300 mg bid tablets). Pts received maintenance treatment until disease progression. Primary endpoint: investigator-assessed PFS (RECIST 1.1) of arm B vs. arm A. Key secondary endpoints: PFS of arm C vs. arm A; OS of arm B vs. arm A, and of arm C vs. arm A. Enrollment began in Q1 2020. Clinical trial information: 2019-004112-60.

Metastasis by semi-quantitative oestrogen receptor expression in stage I-III early diagnosed triple positive breast cancer patients

e13031

Background: Some breast cancer subtype-specific demographics and histopathological characteristics can be associated with metastatic outcome. Semi-quantitative oestrogen receptor (sqER) is prognostic in ER-positive HER2-negative tumours. Here, we studied sqER for outcome in early diagnosed triple positive breast cancers (TPBC;ER+/PR+/HER2+). Methods: Retrospective monocentric study of all consecutive early diagnosed TPBC (July 2002 - Dec 2017). Immunohistochemistry (IHC) was used for ER, PR and HER2; IHC ≥1% ER/PR was pos; HER2 was FISH-confirmed. Low sqER was defined as Allred score < 7/8. Local therapy was surgery +/- radiotherapy; systemic treatment was (neo)-adjuvant chemotherapy and trastuzumab and endocrine treatment. The clinicopathological variables we studied apart from sqER were age, menopausal status, BMI, parity, tumor grade and clinical stage at diagnosis. Variables were analysed by a Fishers Exact or Mann-Whitney U test. All reported p-values are two-sided. Cox regression was used to investigate howqER is associated with distant metastasis. Results: We included 415 female patients. 18% had low sqER; these were younger and more likely premenopausal at diagnosis; p < 0.001. Other studied variables didn’t differ by sqER-expression. 7% developed metastasis after a mean follow up of 86 months. High sqER-TPBCs as compared to low sqER-TPBCs were less likely to metastasize (HR 0.42; 95 CI 0.19-0.91). Conclusions: Low sqER in TPBC, present in about a fifth of these tumours, is typically associated with younger age and premenopausal status at diagnosis. Low sqER TPBC are more likely to metastasize when compared to TPBC with high sqER levels. [Table: see text]

Developing Organoids from Ovarian Cancer as Experimental and Preclinical Models

Ovarian cancer (OC) represents the most dismal gynecological cancer. Pathobiology is poorly understood, mainly due to lack of appropriate study models. Organoids, defined as self-developing three-dimensional in vitro reconstructions of tissues, provide powerful tools to model human diseases. Here, we established organoid cultures from patient-derived OC, in particular from the most prevalent high-grade serous OC (HGSOC). Testing multiple culture medium components identified neuregulin-1 (NRG1) as key factor in maximizing OC organoid development and growth, although overall derivation efficiency remained moderate (36% for HGSOC patients, 44% for all patients together). Established organoid lines showed patient tumor-dependent morphology and disease characteristics, and recapitulated the parent tumor's marker expression and mutational landscape. Moreover, the organoids displayed tumor-specific sensitivity to clinical HGSOC chemotherapeutic drugs. Patient-derived OC organoids provide powerful tools for the study of the cancer's pathobiology (such as importance of the NRG1/ERBB pathway) as well as advanced preclinical tools for (personalized) drug screening and discovery.

•

Organoids are established from ovarian cancer (OC)

•

Neuregulin-1 (NRG1) is identified as key component for OC organoid growth

•

OC organoids capture disease hallmarks and recapitulate patient tumor characteristics

•

OC organoids are amenable to drug screening and mechanistic (NRG1/ERBB) research

Para-aortic lymph node surgical staging in locally-advanced cervical cancer: comparison between robotic versus conventional laparoscopy

OBJECTIVE

With the expansion of the use of minimally invasive surgical techniques within the field of gynecological oncology, a robot assisted procedure seems to be an attractive technique for para-aortic lymph node sampling. The aim of this study was to compare robotic versus conventional laparoscopic para-aortic lymphadenectomy in patients with locally advanced cervical cancer.

METHODS

In this monocentric retrospective study, we included patients with locally-advanced cervical cancer (International Federation of Gynecology and Obstetrics (FIGO) 2009 stage IB2-IVA or IB1 with suspicious pelvic lymph nodes), who underwent a para-aortic lymphadenectomy up to the inferior mesenteric artery between December 1994 and December 2016 (robotic technique starting from December 2012).

RESULTS

A total of 217 patients were included in the study (robotic, n=55 vs laparoscopic, n=162). When comparing conventional laparoscopic versus robotic para-aortic lymphadenectomy, the median age was 48 versus 49 years and the median body mass index was 24.4 vs 24.7 kg/m², respectively. In the robotic or laparoscopic group, 85% and 83% were squamous carcinomas, respectively. Patients who underwent a robotic procedure had a higher American Society of Anesthesiologists (ASA) score (ASA2: 62% vs 56%, ASA3: 20% vs 2%, p<0.001), more prior major abdominal surgery (18% vs 6%, p=0.016), less estimated blood loss (median, 25 mL vs 62.5 mL, p<0.001), more para-aortic lymph nodes removed (11 vs 6, p<0.001), shorter postoperative stay (1.8 vs 2.3 days, p=0.002), and a higher, but non-significant, rate of metastatic para-aortic lymph nodes (13% vs 5%, p=0.065) compared with the laparoscopic procedure, respectively. There was no difference in complication rates between the two approaches. The most frequent complications were grade I and grade II according to the Clavien Dindo classification. No difference was observed in progression-free survival between robotic and laparoscopic para-aortic lymphadenectomy after 2 years (both groups 66%) (p=0.472). Also, 2 year overall survival was similar between the groups (77% vs 81% for robotic vs conventional laparoscopy group, respectively) (p=0.749).

CONCLUSION

Robotic para-aortic lymphadenectomy in patients with locally-advanced cervical cancer resulted in better perioperative outcomes and similar survival outcomes when compared with a conventional laparoscopic approach.

Abstract P2-14-23: Outcome of patients with triple-negative breast cancer who did not receive adjuvant chemotherapy

Introduction Based on immunohistochemistry, triple-negative breast cancer (TNBC) lacks ER, PR and HER2, rendering them non-eligible for hormone or HER2 targeted therapy. Adjuvant chemotherapy (aCT) is often not initiated based on clinical decision making (low risk of relapse, comorbidities, older age), but sometimes because of patient refusal. We aimed to compare clinical-pathologic characteristics and outcome of patients with TNBC by reason to abstain from aCT (based on a clinical decision or patient refusal) with patients who did receive aCT. Methods In this retrospective study, we consecutively included patients with primary operable TNBC who received primary surgery, diagnosed and treated at University Hospitals Leuven between 2000-2017 (median follow-up of 9 years). The underlying reason for patients who did not receive aCT was obtained by performing a chart review: (1) by clinical decision for various different reasons: e.g. low risk of relapse (special histological subtypes e.g. adenoid cystic carcinoma, small pN0 lesions), comorbidities, older age or (2) by patient refusal. Distant disease-free survival (DDFS) and breast cancer-specific survival (BCSS) were studied endpoints. Cox proportional hazard regression models were used to estimate hazard ratios (HR) and 95% confidence intervals. All statistical tests are two-sided, a 5% significance level was assumed for all tests. Analyses have been performed using SAS software (version 9.4 of the SAS System for Windows). Results We included 673 patients with TNBC of whom 163 (24.2%) did not receive aCT; 141 (20.9%) due to a clinical decision, and 22 (3.3%) due to patient refusal. Mean age at diagnosis was 71.6 years and 68.7 years, respectively, compared to 52.3 years for those who received aCT. Patients who received aCT showed a tendency towards better DDFS when compared to the group of patients who refused aCT (HR=0.621 [0.217;1.774]; p=0.37), and when compared to the group who did not receive aCT due to a clinical decision (HR=0.545 [0.294;1.009]; p=0.05). The group of patients who did not receive aCT due to a clinical decision showed a tendency towards worse DDFS compared to the group of patients who refused aCT (HR=1.140 [0.390;3.30]; p=0.81), however this difference was not statistically significant. Interestingly, BCSS for patients who received aCT was better compared to patients who did not receive aCT due to a clinical decision (HR=0.484 [0.250;0.935]; p=0.03) and showed a tendency towards better survival when compared to the group of patients who refused aCT (HR= 0.582 [0.174;1.946]; p=0.38). Patients who did not receive aCT due to a clinical decision showed a tendency towards worse BCSS than patients refusing therapy (HR=1.204 [0.353;4.089]; p=0.77). Conclusion In this cohort, TNBC patients treated with primary surgery who refused aCT appeared to have worse DDFS and BCSS compared to patients who received aCT. Patients who did not receive aCT due to a clinical decision hade worse BCSS and a tendency towards worse DDFS, compared to patients who received aCT. These results suggest that chemotherapy is effective in reducing cancer-related mortality.

Citation Format: Hava Izci, Jan Ardui, Annouschka Laenen, Freija Verdoodt, Giuseppe Floris, Laurence Slembrouck, Ignace Vergote, Ann Smeets, Els Van Nieuwenhuysen, Sileny Han, Ines Nevelsteen, Caroline Weltens, Patrick Berteloot, Kevin Punie, Hans Wildiers, Patrick Neven. Outcome of patients with triple-negative breast cancer who did not receive adjuvant chemotherapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-14-23.

Abstract P3-08-18: Risk of breast-cancer recurrence after a 10-year disease-free interval

Background: Breast cancer is a disease that can recur even after 20 years of diagnosis. At the moment it remains difficult to predict which women will have a late relapse as most scientific research is conducted for relapse within 10 years following diagnosis. A recent meta-analysis by Pan et al was the first to look at risk factors for relapse in the second decade after diagnosis. However this paper mostly included patients that were treated before the year 2000, which makes the results less applicable to patients nowadays.

Objective: We retrospectively explored known early relapse risk factors for late relapse in a population that was diagnosed between year 2000 and 2008, 10-year disease-free and treated in one center.

Patients and methods: We included all patients, diagnosed with invasive breast cancer who remained disease-free for 10 years. We selected these from a prospectively managed database of consecutive treated patients in the University Hospitals Leuven for early breast cancer, diagnosed between 01-01-2000 and 01-08-2008. We analyzed the association of patient and tumor characteristics for relapse during the second decade after diagnosis. A disease-free survival event (invasive or in situ) was defined as local (ipsi- and contralateral breast), loco-regional (ipsi- and contralateral axillary, internal mammary and subclavian lymph nodes) or metastatic. For the statistical analysis we used Cox proportional hazard models, with time to recurrence as response variable. Furthermore, a multivariable model of independent predictors was constructed using backward selection.

Results: 2757 patients were included with a median follow-up of 13.78 years since initial diagnosis (range=10.01-18.65). Out of this group, 179 patients (6,5%) had a disease-free survival event (6 were in situ carcinoma). The multivariate analysis showed a higher risk of relapse in patients with a younger age (HR=1.044, p=0.0002), higher BMI (HR=1.036, p=0.0243) and postmenopausal status at diagnosis (HR=2.266, p=0.0012), higher tumor grade (HR=1.943, p=0.0151), more lymph node involvement (HR=1.626, p&lt;0.0001) and HER-2 negativity (HR=0.378, p=0.0087). Tumor size, hormone sensitivity and ductal versus lobular carcinoma showed no significant results.

Conclusion: Several patient and tumor related factors proved to be significant independent risk factors for late relapse (&gt;10 years after diagnosis). Our findings may help to differentiate between patients with high and low risk of relapse beyond 10 years of treatment and in this way, provide them with a more personalized form of follow-up.

Citation Format: Anne-Sophie Vertongen, Hans Wildiers, Kevin Punie, Floris Giuseppe, Vergote Ignace, Patrick Berteloot, Toon Van Gorp, Ann Smeets, Els Van Nieuwenhuysen, Han Sileny, Ines Nevelsteen, Annouschka Laenen, Caroline Weltens, Hilde Janssens, Patrick Neven. Risk of breast-cancer recurrence after a 10-year disease-free interval [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-18.

Abstract P3-07-14: Multigene signatures based risk estimates in early ER+/HER2- breast cancer: The predictive value of inexpensive statistical models and changes in adjuvant chemotherapy use

Background Multigene signatures (MGS) select women with estrogen receptor positive human epidermal growth factor receptor 2 negative (ER+/HER2-) breast cancers where adjuvant chemotherapy (aCT) can be avoided. However, MGS are expensive and not always reimbursed. We investigated the predictive value of six inexpensive statistical models in tumors with low or high risk of relapse based on MGS and investigated the change in decision to add chemotherapy following MGS results. Patients and Methods In this retrospective study, we evaluated patients diagnosed with primary operable ER+/HER2- lymph node negative or positive breast cancer diagnosed at University Hospitals Leuven between 2013 and 2018. Tumor tissue of the patients was analyzed by MammaPrint® (MP) (n=25), OncotypeDX® (ODX) (n=44) or Prosigna® (n=57) as there was uncertainty about benefit of aCT during multidisciplinary meeting (MDM). Magee equations (ME), Memorial Sloan Kettering simplified score (MSK), Breast Cancer Recurrence Score Estimator (BCRSE), OncotypeDXCalculator (ODXC), new Adjuvant! Online (nAOL) and PREDICT v2.0 were computed. TAILORx cut-offs were used for ODX. A 85% cut-off was used for the probability of a low (0-25) or high risk (26-100) ODX recurrence score for ODXC and a 5% cut-off was used for 10-year survival benefit with aCT for nAOL and PREDICT. Results All ME- and BCRSE-high cases were classified by MGS as high or intermediate and not as MGS-low risk (Table 1). None of the low risk classifications by ME and nAOL resulted in MGS-high risk with ODX. High risk classification with nAOL showed strong concordance with all MGS-high risk results. A switch in chemotherapy recommendation based on MDM decisions, was observed in 46% (58/126) of patients after MGS results. Following MGS testing, aCT was given to 57 patients which resulted in 17% relative and 10% absolute reduction. Conclusion Inexpensive statistical models based on clinico-pathological parameters can be useful in selecting patients that may need MGS testing. The use of MGS resulted in a substantial decisional switch and reduction in aCT-use.

Table 1 Predictive value of inexpensive statistical models in MGS tested tumors.MGS high risk (n=53)MGS low risk (n=52)ODX (n=17)MP (n=11)Prosigna (n=25)ODX (n=27)MP (n=14)Prosigna (n=11)MSK high (n=32)1038150ME high (n=7)411000BCRSE high (n=6)311000ODXC high (n=4)110010nAOL high (n=105)1772423123PREDICT high (n=47)7512850MSK low (n=37)3361145ME low (n=9)012202BCRSE low (n=50)3310967ODXC low (n=67)35131469nAOL low (n=21)041428PREDICT low (n=79)1061319911

Citation Format: Laurence Slembrouck, Isabelle Vanden Bempt, Hans Wildiers, Ann Smeets, Erik Van Limbergen, Philippe Moerman, Caroline Weltens, Kevin Punie, Griet Hoste, Els Van Nieuwenhuysen, Sileny Han, Ines Nevelsteen, Lynn Jongen, Patrick Neven, Giuseppe Floris. Multigene signatures based risk estimates in early ER+/HER2- breast cancer: The predictive value of inexpensive statistical models and changes in adjuvant chemotherapy use [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-07-14.

Abstract P1-10-07: The presence of ductal carcinoma in situ in core needle biopsy and microcalcifications on mammography in TNBC is associated with a lower pCR and worse long term outcome

Purpose Predictors for pathological Complete Response (pCR) in TNBC are very important given pCR is considered a surrogate marker for breast cancer-related survival. Associated DCIS in TNBC (accom-DCIS) as well as presence of microcalcifications on initial mammography (micro-MG) have been correlated with Androgen Receptor positive TNBC, known to achieve lower pCR rates. We aim to investigate the predictive impact of accom-DCIS and micro-MG on pCR. We also validated known clinico-pathological predictors for pCR. Long term outcome was analyzed for pCR and accom-DCIS. Methods A retrospective cohort study (diagnosed 1/1/2000 - 31/12/2017) of prospectively registered consecutively treated TNBC patients was performed. TNBC was defined as IHC-ER&lt;1%, IHC-PR&lt;1% and IHC-HER2 0-1+ and FISH negative if HER2 IHC 2/3+. All patients had standard of care neoadjuvant chemotherapy (NAC) in our hospital. Patients with at least 2 years of documented follow up and only TNBC of no special type on core needle biopsy (CNB) were included. We evaluated the predictive value of patient factors (age, BMI, symptomatic/screening-detected), imaging (micro-MG) and tumor related factors as reported in the pathology-report (grade, cT, focality, cN, lymphovascular invasion, accom-DCIS) for pCR (defined as pT0-TisN0). We used distant relapse rate and death to evaluate outcome. The Cox proportional hazards model was used to analyze the effect of pCR and accom-DCIS on distant relapse rate as well as overall survival (OS) in a multivariate model (corrected for size, nodal state, grading). Results are presented as hazard ratios (HR) with 95% confidence intervals (CI). Results The study contains 219 patients; accom-DCIS was reported in 53/219 (24.2%) CNB’s; pCR was achieved in 90/219 (41,1%). Patient related factors were comparable in patients who achieved pCR and those who had residual disease. Unifocal, smaller clinical size tumors and high tumor grade were significant predictors for pCR in our series. Analysis of 194 available mammographies showed micro-MG in 63/194 (32.5%). Micro-MG predicted for residual disease after NAC [HR = 3.350; 95% CI (1.708 - 6.569), p=0.005]. Accom-DCIS was a strong negative predictor of pCR [HR = 3.333; 95% CI (1.558 - 7.143), p=0.002)] and was associated with more distant relapse and worse survival [HR = 2.664; 95% CI (1.575 - 4.505), p=0.003]. pCR was strongly associated with a lower distant relapse rate and a better OS [HR = 2.210; 95% CI (1.282 - n3.811), p=0.004]. In the 129 cases without pCR, remaining tumor size [HR = 1.019; 95% CI (1.012 - 1.025), p=&lt; 0,001), ypN [HR = 1.917; 95% CI (1.539 - 2.388), p=&lt; 0,001) and presence of LVI [HR = 3.720; 95% CI (2.057 - 6.728), p=&lt; 0,001] significantly predicted for secondary metastasis. There was only a trend towards more distant relapses if accom-DCIS was found in the resection specimen in those who had residual disease [HR = 1.347; 95% CI (0.780 - 2.325), p=0.2855]. Conclusion Presence of accom-DCIS in CNB as well as micro-MG predicts for less pCR in TNBC. Accom-DCIS in CNB is associated with more distant relapse and worse OS. For accom-DCIS on resection specimen, there was only a tendency towards more distant relapses.

Citation Format: Jan Ardui, Sophie Vandamme, Chantal Van Ongeval, Giuseppe Floris, Hava Izci, Hans Wildiers, Kevin Punie, Tatjana Geukens, Ignace Vergote, Patrick Berteloot, Toon Van Gorp, Ann Smeets, Els Van Nieuwenhuysen, Sileny Han, Annouschka Laenen, Caroline Weltens, Hilde Janssens, Patrick Neven. The presence of ductal carcinoma in situ in core needle biopsy and microcalcifications on mammography in TNBC is associated with a lower pCR and worse long term outcome [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-10-07.

Abstract P5-06-08: Predicting distant recurrence of ER+ HER2- breast cancer after 5 years of endocrine therapy: The CTS5-tool validation in real life

Purpose: Extended adjuvant hormone therapy improves estrogen receptor (ER)-positive breast cancer outcome. The total duration of endocrine therapy is still a subject for debate. The CTS5 score, developed by Dowsett et al1., predicts late distant recurrence (LDR) between years 5 and 10 after diagnosis in ER-positive invasive breast cancers in postmenopausal women. This LDR risk might be used to select patients for extended endocrine therapy. The CTS5 score is calculated using age at the start of endocrine therapy, tumor size, grade, and lymph node status. The aim of this study is the validation of this tool in a series of women from the UZ Leuven.

Methods: This retrospective cohort study included 1125 postmenopausal women consecutively diagnosed with invasive estrogen receptor (ER) positive breast cancer who stopped endocrine therapy after 4.5 to 5.5 years. Tissue was tested for ER positivity and considered positive if &gt;1% of tumor nuclei were stained. HER2 status was defined according to ASCO guidelines. Statistical analysis was performed by Cox proportional hazards models which determined the prognostic performance of the CTS5 score for LDR.

Results: A total of 1125 patients were included in this analysis, of which 1097 had a known HER2 status and 1023 were negative. 62 of 1125 (5.5%) developed an LDR between years 5 and 10. The continuous CTS5 was a significant predictor for LDR (HR =2.69 (1.99-3.60), p&lt;0.001). The tool was not significant in the HER2 positive population (n=74), but numbers were small with only 5 LDR recorded (HR=0.92 (0.32-2.66), p=0.88). Further analysis was performed in a strictly HER2-negative cohort. In this cohort, 8 of the 401 patients (2.0%) with a CTS5 predicted low risk (&lt;5% LDR risk) developed LDR, in the intermediate risk group (5-10% LDR risk) 16 out of 336 (4.8%) and in the high risk group (≥10% LDR risk) 32 out of 286 (11.2%) developed LDR.

Conclusion: In our series of postmenopausal women, CTS5 accurately predicts late distant recurrence in ER-positive, HER2-negative early invasive breast cancers. The CTS5-score, identifying a patient group with LDR risk of ≥5%, might be used to discuss the benefits of extended endocrine therapy for individual patients. However, the exact predictive value for the benefit of prolonged therapy can only be based on a randomized controlled trial (RCT) using the LDR risk as a stratification factor.

It would be of great value to expand the study population, especially HER2-positive tumors, and define the prognostic performance of the CTS5 score in premenopausal women. Further research is needed.

1. Dowsett, M. et al. Integration of Clinical Variables for the Prediction of Late Distant Recurrence in Patients With Estrogen Receptor-Positive Breast Cancer Treated With 5 Years of Endocrine Therapy: CTS5. J. Clin. Oncol. 36, 1941-1948 (2018).

Citation Format: Josephine Van Cauwenberge, Ivana Sestak, Kevin Punie, Hans Wildiers, Giuseppe Floris, Ignace Vergote, Patrick Berteloot, Toon Van Gorp, Ann Smeets, Els Van Nieuwenhuysen, Sileny Han, Ines Nevelsteen, Caroline Weltens, Hilde Janssen, Patrick Neven. Predicting distant recurrence of ER+ HER2- breast cancer after 5 years of endocrine therapy: The CTS5-tool validation in real life [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-06-08.

Abstract P6-10-13: Associated ductal carcinoma in situ in primary operated TNBC is associated with a longer time to distant event

Purpose We studied presence of accompanying ductal adenoma in situ (accom-DCIS) in a consecutive series of primary operated TNBC for distant time-to-event outcome. Methods A retrospective cohort study (diagnosis 1/1/2000 - 31/12/2017) of prospectively registered primary operated TNBC patients in UZ Leuven. Only TNBC of no special type were included. We compared patient (age, BMI, symptomatic/screening-detected) and tumor related factors (Nottingham Prognostic Index (NPI), Lymphovascular Involvement (LVI)) for accom-DCIS and analyzed the effect of accom-DCIS on distant time to event outcome using the Cox proportional hazards model. Multivariate models were used to correct for possible confounders. Results We included 524 patients. Median follow-up was 102 months. Mean age of patient was 57.3 [26-90] years and 361 had accom-DCIS (68,9 %); demographics, clinical-pathological characteristics and postoperative chemo- and radiotherapy were similar in patients with and without accom-DCIS; only LVI was significantly more likely to be present in accom-DCIS cases (p=&lt;0.001). There were no differences in distant relapse rate (16.6% in accom-DCIS group vs 12.9% in no DCIS group [HR = 1.350, 95% CI (0.817;2.248) p=0.239]. Time to distant event was later if accom-DCIS was present: Mean time to distant event was 2.72yrs in the accom-DCIS group and 1.61yrs in the group with absent DCIS. In accom-DCIS 20/63 (31.8%) distant relapses occurred after 3 years while only 1/21 distant relapse (4.8%) occurred after 3 years in the non-DCIS group [HR =6.667, 95% CI (0.952-46.705) p=0,029]. Conclusion In our series of TNBCs, patients with and without accom-DCIS had similar distant relapse rates. Significantly more distant relapse occurred after 3 years in patients with accom-DCIS compared to patients without accom-DCIS.

Citation Format: Jan Ardui, Hans Wildiers, Giuseppe Floris, Hava Izci, Kevin Punie, Tatjana Geukens, Els Van Nieuwenhuysen, Sileny Han, Patrick Berteloot, Annouschka Laenen, Hilde Janssens, Ann Smeets, Caroline Weltens, Ignace Vergote, Patrick Neven. Associated ductal carcinoma in situ in primary operated TNBC is associated with a longer time to distant event [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-10-13.

Publisher Correction: Shared heritability and functional enrichment across six solid cancers

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Decentralization of Next-Generation RNA Sequencing-Based MammaPrint® and BluePrint® Kit at University Hospitals Leuven and Curie Institute Paris

A previously developed and centrally validated MammaPrint® (MP) and BluePrint® (BP) targeted RNA next-generation sequencing (NGS) kit was implemented and validated in two large academic European hospitals. Additionally, breast cancer molecular subtypes by MP and BP RNA sequencing were compared with immunohistochemistry (IHC). Patients with early breast cancer diagnosed at University Hospitals Leuven and Curie Institute Paris were prospectively included between September 2017 and January 2018. Formalin-fixed paraffin-embedded tissue sections were analyzed with MP and BP NGS technology at the beta sites and with both NGS and microarray technology at Agendia. Raw NGS data generated on Illumina MiSeq instruments at the beta sites were interpreted and compared with NGS and microarray data at Agendia. MP and BP NGS molecular subtypes were compared to surrogate IHC breast cancer subtypes. Equivalence of MP and BP indices was determined by Pearson's correlation coefficient. Acceptable limits were defined a priori, based on microarray data generated at Agendia between 2012 and 2016. The concordance, the Negative Percent Agreement and the Positive Percent Agreement were calculated based on the contingency tables and had to be equal to or higher than 90%. Out of 124 included samples, 48% were MP Low and 52% High Risk with microarray. Molecular subtypes were BP luminal, HER2 or basal in 82%, 8% and 10% respectively. Concordance between MP microarray at Agendia and MP NGS at the beta sites was 91.1%. Concordance of MP High and Low Risk classification between NGS at the beta sites and NGS at Agendia was 93.9%. Concordance of MP and BP molecular subtyping using NGS at the beta sites and microarray at Agendia was 89.5%. Concordance between MP and BP NGS subtyping, and IHC was 71.8% and 76.6%, for two IHC surrogate models. The MP/BP NGS kit was successfully validated in a decentralized setting.

Abstract 1406: Multigene signatures based risk estimates in ER+/HER2- breast cancers: The predictive value of inexpensive statistical models and changes in adjuvant chemotherapy use

Background Multigene signatures (MGS) select women with estrogen receptor positive human epidermal growth factor receptor 2 negative (ER+/HER2-) breast cancers where adjuvant chemotherapy (aCT) can be avoided. However, MGS are expensive and not always reimbursed. We investigated the predictive value of five inexpensive statistical models in tumors with low or high risk of relapse based on MGS and investigated the change in decision to add chemotherapy following MGS results.

Patients and Methods In this retrospective study, we evaluated patients diagnosed with primary operable ER+/HER2- lymph node negative or positive breast cancer diagnosed at University Hospitals Leuven between 2013 and 2018. Patients were analyzed by MammaPrint® (MP) (n=24), OncotypeDX® (ODX) (n=44) or Prosigna®(n=57) as there was uncertainty about benefit of aCT during multidisciplinary meeting (MDM). Magee equations (ME), Memorial Sloan Kettering simplified score (MSK), Breast Cancer Recurrence Score Estimator (BCRSE), new Adjuvant! Online (nAOL) and PREDICT v2.0 were computed. TAILORx cut-offs were used for ODX. A 5% cut-off was used for 10-year survival benefit with aCT for nAOL and PREDICT.

Results All ME- and BCRSE-high cases were classified by MGS as high or intermediate and not as MGS-low risk, as shown in Table 1. None of the low risk classifications by ME and nAOL resulted in MGS-high risk with ODX. High risk classification with nAOL showed strong concordance with all MGS-high risk results. Chemotherapy switch according to MGS results was observed in 46% (57/125) of patients. Following MGS testing, aCT was given to 56 patients which resulted in 19% relative and 10% absolute reduction.

Conclusion Inexpensive statistical models based on pathologic parameters can be useful to select patients who may need MGS testing. Integration of MGS into MDM decisions, resulted in a substantial decisional switch and reduction in aCT administration.

Table 1Predictive value of inexpensive statistical models in MGS tested tumors.MGS high risk (n=52)MGS low risk (n=52)ODX (n=17)MP (n=10)Prosigna (n=25)ODX (n=27)MP (n=14)Prosigna (n=11)MSK high59% (10/17)30% (3/10)32% (8/25)4% (1/27)36% (5/14)0% (0/11)ME high24% (4/17)10% (1/10)4% (1/25)0% (0/27)0% (0/14)0% (0/11)BCRSE high0% (0/17)10% (1/10)4% (1/25)0% (0/27)0% (0/14)0% (0/11)nAOL high100% (17/17)60% (6/10)96% (24/25)85% (23/27)86% (12/14)27% (3/11)PREDICT high47% (8/17)40% (4/10)48% (12/25)26% (7/27)36% (5/14)0% (0/11)MSK low18% (3/17)30% (3/10)24% (6/25)41% (11/27)29% (4/14)46% (5/11)ME low0% (0/17)10% (1/10)8% (2/25)7% (2/27)0% (0/14)18% (2/11)BCRSE low18% (3/17)30% (3/10)40% (10/25)26% (7/27)43% (6/14)64% (7/11)nAOL low0% (0/17)40% (4/10)4% (1/25)15% (4/27)14% (2/14)73% (8/11)PREDICT low53% (9/17)60% (6/10)52% (13/25)74% (20/27)64% (9/14)100% (11/11)

Citation Format: Laurence Slembrouck, Giuseppe Floris, Hans Wildiers, Ann Smeets, Erik Van Limbergen, Philippe Moerman, Caroline Weltens, Kevin Punie, Griet Hoste, Els Van Nieuwenhuysen, Sileny Han, Ines Nevelsteen, Lynn Jongen, Patrick Neven, Isabelle Vanden Bempt. Multigene signatures based risk estimates in ER+/HER2- breast cancers: The predictive value of inexpensive statistical models and changes in adjuvant chemotherapy use [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1406.