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.

Abstract 5785: A pan-cancer single-cell tumor micro-environment atlas predictive of immunotherapy response

The tumor microenvironment (TME) shapes response to immune checkpoint blockade (ICB). Several pan-cancer single-cell RNA-sequencing (scRNA-seq) analyses have reported how TME heterogeneity profoundly differs between cancer types. These studies mainly focused on one cell type (e.g., T-cells) and combined different technologies and bioinformatics pipelines with data being collected from both published and newly generated datasets. A comprehensive pan-cancer scRNA-seq map of the TME involving all cell types is therefore still lacking.

We obtained scRNA-seq (10x Genomics) on 234 fresh tissue samples from 161 treatment-naïve patients. Samples were collected from 9 cancer types and subjected to a uniform in-house optimized protocol of tissue dissociation, sequencing and bioinformatics analysis. Abundancies of cell types and subtypes were correlated with each other and a tumor-reactive T-cell signature.

From 683,184 high-quality single cells, we identified 9 cell types and 71 subtypes of T-cells, B-cells, dendritic cells (DCs), monocytes/macrophages and endothelial-cells (ECs), shared between cancer types. PDCD1 (PD1) was expressed by differentiated T-cells subtypes (e.g., CD8+ exhausted and CD4+ T-helper-1 subclusters), while CD274 and PDCD1LG (PDL-1/PDL-2) were mainly expressed by regulatory B-cells, immune-regulatory DCs, CXCL10+ and CCL2+ monocyte-derived macrophages as well as inflammatory ECs. Pairwise analyses showed positive correlations between PD1-expressing T-cell subclusters, CD4+ T-regulatory cells, plasma B-cells (plasmablasts, IgA and IgG plasma cells), immune-regulatory DCs, CXCL10+ and CCL2+ macrophages and lymphatic ECs. On the other hand, negative correlations were observed with naïve T- and B-cells, conventional DC2 (cDC2), monocytes, CX3CR1+ macrophages, as well as arterial and capillary ECs. When ranking individual tumors based on a tumor-reactive T-cell signature, we found reactive tumors to correlate with positively interacting subtypes, while they anti-correlated with subclusters negatively interacting with PD1-expressing differentiated T-cells. Upon deconvolution of bulk RNA-seq data using gene signatures derived from each subcluster, these correlations were replicated in TCGA datasets across cancers. These signature scores correlated with tumor mutation burden (TMB) and other immunological features, while they were also predictive of response in clinical trials involving ICB.

We provide insights into the TME complexity at unprecedented level, identifying numerous subclusters enriched in immune-reactive (hot) or -suppressive (cold) tumors across cancer types. We validate these observations in TCGA by deconvolution of bulk RNA-seq data, and show that already pre-treatment several TME subclusters predict response to ICB.

Citation Format: Francesca Lodi, Sam Vanmassenhove, Elena Donders, Pierre Van Mol, Amelie Franken, Sarah Cappuyns, Ayse Bassez, Siel Olbrecht, Liselore Loverix, Michel Bila, Hanne Vos, Joanna Pozniak, Kevin Punie, Diether Lambrechts. A pan-cancer single-cell tumor micro-environment atlas predictive of immunotherapy response. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5785.

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.

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.

MCM3 is a novel proliferation marker associated with longer survival for patients with tubo-ovarian high-grade serous carcinoma

Tubo-ovarian high-grade serous carcinomas (HGSC) are highly proliferative neoplasms that generally respond well to platinum/taxane chemotherapy. We recently identified minichromosome maintenance complex component 3 (MCM3), which is involved in the initiation of DNA replication and proliferation, as a favorable prognostic marker in HGSC. Our objective was to further validate whether MCM3 mRNA expression and possibly MCM3 protein levels are associated with survival in patients with HGSC. MCM3 mRNA expression was measured using NanoString expression profiling on formalin-fixed and paraffin-embedded tissue (N = 2355 HGSC) and MCM3 protein expression was assessed by immunohistochemistry (N = 522 HGSC) and compared with Ki-67. Kaplan-Meier curves and the Cox proportional hazards model were used to estimate associations with survival. Among chemotherapy-naïve HGSC, higher MCM3 mRNA expression (one standard deviation increase in the score) was associated with longer overall survival (HR = 0.87, 95% CI 0.81-0.92, p < 0.0001, N = 1840) in multivariable analysis. MCM3 mRNA expression was highest in the HGSC C5.PRO molecular subtype, although no interaction was observed between MCM3, survival and molecular subtypes. MCM3 and Ki-67 protein levels were significantly lower after exposure to neoadjuvant chemotherapy compared to chemotherapy-naïve tumors: 37.0% versus 46.4% and 22.9% versus 34.2%, respectively. Among chemotherapy-naïve HGSC, high MCM3 protein levels were also associated with significantly longer disease-specific survival (HR = 0.52, 95% CI 0.36-0.74, p = 0.0003, N = 392) compared to cases with low MCM3 protein levels in multivariable analysis. MCM3 immunohistochemistry is a promising surrogate marker of proliferation in HGSC.

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.

Association of a Combined Cancer Exhaustion Score with Circulating Tumor Cells and Outcome in Ovarian Cancer-A Study of the OVCAD Consortium

We investigated the prognostic role of systemic characteristics for cancer exhaustion and the presence of circulating tumor cells (CTCs) in primary epithelial ovarian cancer (EOC) patients. We included 185 patients in this multicenter study with a median follow-up time of 10.25 years. Albumin, c-reactive protein (CRP) and the kynurenine to tryptophan ratio (Kyn/Trp) as well as the CTC-related marker cyclophilin C (PPIC) were obtained before primary therapy and were correlated to the respective clinical and outcome data. The information provided by albumin and Kyn/Trp was integrated in a combined score for cancer exhaustion (CCES). A high CCES characterized by hypoalbuminemia and a high Kyn/Trp was associated with both decreased overall and progression-free survival, independent from other known prognostic factors in a multivariable analysis. The presence of PPIC-positive CTCs was significantly associated with a high CCES, highlighting that the interplay between the systemic microenvironment and CTCs should be considered in "liquid biopsy" biomarker assessment.

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.

The Long-Term Prognostic Significance of Circulating Tumor Cells in Ovarian Cancer-A Study of the OVCAD Consortium

INTRODUCTION

We previously reported the prognostic impact of circulating tumor cells (CTCs) in a multicenter study on minimal residual disease in primary ovarian cancer. With additional follow-up data, we evaluated the combined CTC approach (CTCs^combo), in particular for the patients who had survived more than five years.

MATERIAL AND METHODS

Blood samples taken at baseline and six months after adjuvant treatment (follow-up) were assessed by quantitative PCR (qPCR) measuring PPIC transcripts and immunofluorescent staining (IF). A positive result with either IF or qPCR was classified as CTC^combo-positive. Further, PPIC was assessed in the primary tumor tissue.

RESULTS

The concordance of IF and qPCR was 65% at baseline and 83% after treatment. Results showed that 50.5% of the baseline and 29.5% of the follow-up samples were CTC^combo-positive. CTCs^combo after treatment were associated with increased mortality after adjusting for FIGO stage (HR 2.574, 95% CI: 1.227-5.398, p = 0.012), a higher risk of recurrence after adjusting for peritoneal carcinosis (HR 4.068, 95% CI: 1.948-8.498, p < 0.001), and increased mortality after five survived years.

DISCUSSION

The two-sided analytical approach revealed CTC subpopulations associated with ovarian cancer progression and may illuminate a potential treatment-related shift in molecular phenotypes. That approach can identify patients who have elevated risk of recurrence and death due to ovarian cancer and who may require risk-adapted treatment strategies.

miR-181a overexpression predicts the poor treatment response and early-progression of serous ovarian cancer patients

Ovarian cancer (OC) remains a leading cause of gynecological cancer-related death worldwide, characterized by poor 5-year survival. Molecular markers could serve as crucial tools of personalized prognosis and therapy. Herein, we present miR-181a as novel predictor of OC prognosis, using five independent OC cohorts. In particular, a screening (n = 81) and an institutionally independent validation (n = 100, OVCAD multicenter study) serous OC (SOC) cohorts were analyzed. Bagnoli et al (2016) OC179 (n = 124) to OC133 (n = 100) and TCGA (n = 489) served as external validation cohorts. Patients' survival and disease progression were assessed as clinical endpoint events. Bootstrap analysis was performed for internal validation and decision curve analysis was utilized to evaluate clinical benefit. miR-181a overexpression was unveiled as powerful and independent molecular predictor of patients' poor survival and higher risk for disease progression after debulking surgery and platinum-based chemotherapy. Analysis of the OVCAD institutionally independent cohort, as well as of Bagnoli et al. and TCGA external cohorts further confirmed the unfavorable prognostic nature of miR-181a overexpression in SOC. Strikingly, multivariate prognostic models incorporating miR-181a with established disease markers clearly improved patients' risk-stratification and offered superior clinical benefit in OC prognostication. Conclusively, miR-181a evaluation could augment prognostic accuracy and support precision medicine decisions in OC.

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.

Successful non-surgical treatment of endocarditis caused by Staphylococcus haemolyticus following transcatheter aortic valve implantation (TAVI)

We describe a case of a 79-year-old male patient with severe aortic stenosis who underwent transcatheter aortic valve implantation (TAVI) at our institution. He presented at the emergency department with dyspnea and fatigue 7 months after implantation. The diagnosis of early prosthetic valve endocarditis (PVE) caused by Staphylococcus haemolyticus was made by transesophageal echocardiography (TEE) and multiple positive blood cultures. Since our patient was considered inoperable due to a history of coronary artery bypass graft (CABG) surgery with patent bypasses, high peri-operative mortality including renal failure and a poor general prognosis, surgical removal of the valve was not an option. The patient was successfully treated with antibiotic therapy.