Randomized phase II BGOG/ENGOT-cx1 study of paclitaxel-carboplatin with or without nintedanib in first-line recurrent or advanced cervical cancer

OBJECTIVE

Nintedanib is an oral tyrosine kinase inhibitor targeting, among others, vascular endothelial growth factor receptor. The aim was to establish the role of nintedanib in addition to paclitaxel and carboplatin in first-line recurrent/metastatic cervical cancer.

METHODS

Double-blind phase II randomized study in patients with first-line recurrent or primary advanced (FIGO stage IVB) cervical cancer. Patients received carboplatin-paclitaxel with oral nintedanib 200 mg BID/placebo. The primary endpoint was progression-free survival (PFS) at 1.5 years and α = 0.15, β = 80%, one sided.

RESULTS

120 patients (62 N, 58C) were randomized. Median follow-up was 35 months. Baseline characteristics were similar in both groups (total population: squamous cell carcinoma 62%, prior radiotherapy 64%, primary advanced 25%, recurrent 75%). The primary endpoint was met with a PFS at 1.5 years of 15.1% versus 12.8% in favor of the nintedanib arm (p = 0.057). Median overall survival (OS) was 21.7 and 16.4 months for N and C, respectively. Confirmed RECIST response rate was 48% for N and 39% for C. No new adverse events were noted for N. However, N was associated with numerically more serious adverse events for anemia and febrile neutropenia. Global health status during and at the end of the study was similar in both arms.

CONCLUSION

The study met its primary endpoint with a prolonged PFS in the N arm. No new safety signals were observed.

Features of durable response and treatment efficacy for capecitabine monotherapy in advanced breast cancer: real-world evidence from a large single-centre cohort

PURPOSE

In metastatic breast cancer (MBC) population treated with capecitabine monotherapy, we investigated clinical-pathological features as possible biomarkers for the oncological outcome.

METHODS

Retrospective study of consecutive MBC patients treated at University Hospitals Leuven starting capecitabine between 1999 and 2017. The primary endpoint was the durable response (DR), defined as non-progressive disease for > 52 weeks. Other main endpoints were objective response rate (ORR), time to progression (TTP) and overall survival (OS).

RESULTS

We included 506 patients; mean age at primary breast cancer diagnosis was 51.2 years; 18.2% had de novo MBC; 98.8% were pre-treated with taxanes and/or anthracycline. DR was reached in 11.6%. Patients with DR, as compared to those without DR, were more likely oestrogen receptor (ER) positive (91.5% vs. 76.8%, p = 0.010) at first diagnosis, had a lower incidence of lymph node (LN) involvement (35.6% vs. 49.9%, p = 0.039) before starting capecitabine, were more likely to present with metastases limited to ≤ 2 involved sites (54.2% vs. 38.5%, p = 0.020) and time from metastasis to start of capecitabine was longer (mean 3.5 vs. 2.7 years, p = 0.020). ORR was 22%. Median TTP and OS were 28 and 58 weeks, respectively. In multivariate analysis (only performed for TTP), ER positivity (hazard ratio (HR) = 0.529, p < 0.0001), HER2 negativity (HR = 0.582, p = 0.024), absence of LN (HR = 0.751, p = 0.008) and liver involvement (HR = 0.746, p = 0.013), older age at capecitabine start (HR = 0.925, p < 0.0001) and younger age at diagnosis of MBC (HR = 0.935, p = 0.001) were significant features of longer TTP.

CONCLUSION

Our data display relevant clinical-pathological features associated with DR and TTP in patients receiving capecitabine monotherapy for MBC.

Curative effect of second curettage for treatment of gestational trophoblastic disease - Results of the Belgian registry for gestational trophoblastic disease

OBJECTIVE

We assessed the curative effect of a second curettage in patients with persistent hCG serum levels after first curettage for a gestational trophoblastic disease (GTD).

STUDY DESIGN

This prospective observational study used the data of the Belgian register for GTD between July 2012 and January 2017. We analysed the data of patients who underwent a second curettage. We included 313 patients in the database. Primary endpoints were need for second curettage and chemotherapy.

RESULTS

Thirty-seven patients of the study population (12 %) underwent a second curettage. 20 had persistent human chorionic gonadotropin hormone (hCG) elevation before second curettage. Of them, 9 patients (45 %) needed no further treatment afterwards. Eleven patients (55 %) needed further chemotherapy. Nine (82 %) were cured with single-agent chemotherapy and 2 patients (18 %) needed multi-agent chemotherapy. Of the 37 patients, patients with hCG levels below 5000 IU/L undergoing a second curettage were cured without chemotherapy in 65 % versus 45 % of patients with hCG level more than 5000 IU/L. Of the ten patients with a hCG level below 1000 IU/L, eight were cured without chemotherapy.

CONCLUSIONS

Patients with post-mole gestational trophoblastic neoplasia can benefit from a second curettage to avoid chemotherapy, especially when the hCG level is lower than 5000 IU/L.

Robot-assisted surgery for women with endometrial cancer: Surgical and oncologic outcomes within a Belgium gynaecological oncology group cohort

OBJECTIVE

To evaluate surgical and oncologic outcomes of patients treated by robot-assisted surgery for endometrial cancer within the Belgium Gynaecological Oncology Group (BGOG).

STUDY DESIGN

We performed a retrospective analysis of women with clinically Stage I endometrial cancer who underwent surgical treatment from 2007 to 2018 in five institutions of the BGOG group.

RESULTS

A total of 598 consecutive women were identified. The rate of conversion to laparotomy was low (0.8%). The mean postoperative Complication Common Comprehensive Index (CCI) score was 3.4. The rate of perioperative complications did not differ between age groups, however the disease-free survival was significantly lower in patients over 75 years compared to patients under 65 years of age (p=0.008). Per-operative complications, conversion to laparotomy rate, post-operative hospital stay, CCI score and disease-free survival were not impacted by increasing BMI.

CONCLUSION

Robot-assisted surgery for the surgical treatment of patients suffering from early-stage endometrial cancer is associated with favourable surgical and oncologic outcomes, particularly for unfavourable groups such as elderly and obese women, thus permitting a low morbidity minimally-invasive surgical approach for the majority of patients in expert centres.

Phase 2 study of the Exportin 1 inhibitor selinexor in patients with recurrent gynecological malignancies

BACKGROUND

Selinexor is an oral inhibitor of the nuclear export protein Exportin 1 (XPO1) with demonstrated antitumor activity in solid and hematological malignancies. We evaluated the efficacy and safety of selinexor in heavily pretreated, recurrent gynecological malignancies.

METHODS

In this phase 2 trial, patients received selinexor (35 or 50 mg/m2 twice-weekly [BIW] or 50 mg/m2 once-weekly [QW]) in 4-week cycles. Primary endpoint was disease control rate (DCR) including complete response (CR), partial response (PR) or stable disease (SD) ≥12 weeks. Secondary endpoints were progression-free survival (PFS), overall survival (OS) and safety.

RESULTS

114 patients with ovarian (N = 66), endometrial (N = 23) or cervical (N = 25) cancer were enrolled. Median number of prior regimens for ovarian, endometrial and cervical cancer was 6 (1-11), 2 (1-5), and 3 (1-6) respectively. DCR was 30% (ovarian 30%; endometrial 35%; cervical 24%), which included confirmed PRs in 8%, 9%, and 4% of patients with ovarian, endometrial, and cervical cancer respectively. Median PFS and OS for patients with ovarian, endometrial and cervical cancer were 2.6, 2.8 and 1.4 months, and 7.3, 7.0, and 5.0 months, respectively. Common Grade 3/4 adverse events (AEs) were thrombocytopenia (17%), fatigue (14%), anemia (10%), nausea (9%) and hyponatremia (9%). Patients with ovarian cancer receiving 50 mg/m2 QW had fewer high-grade AEs with similar efficacy as BIW treatment.

CONCLUSIONS

Selinexor demonstrated single-agent activity and disease control in patients with heavily pretreated ovarian and endometrial cancers. Side effects were a function of dose level and treatment frequency, similar to previous reports, reversible and mitigated with supportive care.

Expression III: patients' expectations and preferences regarding physician-patient relationship and clinical management-results of the international NOGGO/ENGOT-ov4-GCIG study in 1830 ovarian cancer patients from European countries

Backround

The primary aim of this study was to investigate information needs and treatment preferences of patients with ovarian cancer, focusing especially on physician-patient relationship and treatment.

Patients and methods

A questionnaire was developed based on the experiences of the national German survey 'Expression II', and was provided to patients with ovarian cancer either at initial diagnosis or with recurrent disease via Internet (online-version) or as print-out-version.

Results

From December 2009 to October 2012, a total of 1830 patients with ovarian cancer from eight European countries (Austria, Belgium, France, Germany, Italy, Poland, Romania, Spain) participated, 902 (49.3%) after initial diagnosis and 731 (39.9%) with recurrent ovarian cancer. The median age was 58 years (range 17-89). Nearly all patients (96.2%) had experienced upfront surgery followed by first-line chemotherapy (91.8%). The majority of patients were satisfied with the completeness and comprehensibility of the explanation about the diagnosis and treatment options. The three most important aspects, identified by patients to improve the treatment for ovarian cancer included: 'the therapy should not induce alopecia' (42%), 'there must be more done to counter fatigue' (34.5%) and 'the therapy should be more effective' (29.7%). Out of 659 (36%) patients, who were offered participation in a clinical trial, 476 (26%) were included.

Conclusion

This study underlines the high need of patients with ovarian cancer for all details concerning treatment options irrespective of their cultural background, the stage of disease and the patient's age. Increased information requirements regarding potential side effects and treatment alternatives were recorded. Besides the need for more effective therapy, alopecia and fatigue are the most important side effects of concern to patients.

Abstract PD3-09: Efficacy of HER2 inhibitors in metastatic breast cancer by discordance in HER2 amplification status between primary and metastatic breast cancer

Purpose:

In stage IV breast cancer (BC), discordance in the human epidermal growth factor receptor 2 (HER2) amplification status between primary and metastatic BC might affect efficacy of HER2-targeted agents. We studied progression free (PFS) and overall survival (OS) dependent on HER2 concordance in patients treated with a first line taxane-trastuzumab combination and later line trastuzumab-emtansine (T-DM1).

Patients and Methods:

This retrospective monocentric study included 76 patients with metastatic BC under treatment with trastuzumab in which a biopsy from both the primary and metastatic site was available. HER2 amplification status, sex-steroid receptor status, Nottingham prognostic index, distant metastasis-free interval and consecutive lines of therapy were retrieved from patients' reports. The Kaplan-Meier method was used for estimating PFS/OS and log-rank test for analyzing between group differences. A Cox model is used for testing difference between groups while correcting for Pertuzumab. Multivariable Cox regression is used to model OS as a function group, correcting for possible confounders.

Results:

Discordance in HER2 amplification status was seen in 30 out of 76 patients (39%), 11 patients lost HER2 amplification in the metastatic lesion (HER2lost) while 19 acquired HER2 amplification (HER2acquired). The other 46 patients had a HER2 amplification on both primary and metastatic site (HER2stable). The HER2lost group had a significant lower median PFS (PFS= 5.5 months) for taxane-trastuzumab, after correcting for pertuzumab, compared to the HER2stable group (PFS= 9 months, corrected p= 0.0146) and HER2acquired group (PFS=14 months, corrected p=0.0121). For T-DM1 treatment, both discordant groups, HER2acquired (PFS=1.1 months, p=0.0373) and HER2lost (PFS=1.5 months, p=0.0116), had a significant lower PFS compared to the HER2stable group (PFS=6.0 months). After correcting for possible confounders, HER2lost had a significant worse OS compared to HER2stable (HR 0.187, 95% CI 0.079 – 0.439) and HER2acquired (HR 0.147, 95% 0.058-0.378).

Conclusion:

Loss of HER2 amplification in metastatic lesions seems to have a negative predictive value for PFS on HER2-targeted agents and negative prognostic impact on OS. Acquiring of HER2 amplification was predictive for lower PFS on T-DM1 but wasn't predictive for lower PFS on taxane-trastuzumab.

Citation Format: Van Raemdonck E, Berteloot P, Laenen A, Han S, Van Nieuwenhuysen E, Salihi R, Concin N, Vergote I, Floris G, Wildiers H, Punie K, Neven P. Efficacy of HER2 inhibitors in metastatic breast cancer by discordance in HER2 amplification status between primary and metastatic breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD3-09.

Abstract P3-03-32: Monocentric experience with the sentinel lymph node biopsy prior to neoadjuvant chemotherapy in clinically lymph node negative early breast cancer

Background

In patients with clinically lymph node negative (cN0) early breast cancer (EBC) treated with neoadjuvant chemotherapy (NACT), the sentinel lymph node biopsy (SLNB) can be performed before or after NACT. We report safety of axillary staging performing the SLNB prior to NACT in cN0 EBC and estimate NACT-induced downstaging to ypN0 in previously NACT-treated cN1 EBC, to make an assumption for avoiding axillary lymph node dissection (ALND) if SLNB was done after NACT.

Patients and Methods

Monocentric retrospective study of consecutive triple negative (TNBC) and HER-2 amplified BC patients treated with standard NACT. cN0 patients had SLNB before NACT followed by local therapy. Axillary lymph node dissection (ALND) post-NACT was performed in all cN1 and in cN0 cases with a positive or failed SLNB. Using descriptive statistics, we here report SLNB-detection and SLNB-positive rate, SLNB-operative complications, complete tumor regression in the breast (ypT0/is) and disease-free survival (DFS) for cN0 cases and NACT-induced downstaging to ypN0 in previously NACT-treated cN1 EBC.

Results

We included 245 NACT-treated patients; 119 cN0 and 126 cN1. SLNB-detection rate in cN0 cases was 99,2%; 25 or 21% had ≥ 1 involved SLN, 21.8% experienced SLNB related-complications (e.g. infection, seroma, hematoma) leading to NACT-delay in 3 and interruption in 1 patient. Median start of NACT after SLNB was 7 days (range 1-20 days). In patients with a positive SLNB, there were no additional involved nodes in the ALND. In 5 of these patients, therapy response in a lymph node was described. Complete tumor regression in the breast (ypT0/is) was 52% in SLNB-positive and 59,1% in SLNB-negative cN0 cases. NACT-induced ypN0 was 61% in cN1 cases. At 30 months of median follow-up (range 1-86 months), DFS was 93,2% (4.2% metastatic; no axillary relapse) in cN0 cases. Median DFS was better for patients with complete tumor regression in the breast as compared to those with partial response; 95.6% and 90% respectively.

Conclusion

In conclusion, performing SLNB before NACT in cN0 cases is a safe and accurate method. While some pN1(sn) could have avoid ALND by NACT-induced axillary down-staging, based on our assumption, long term follow-up is needed to conclude whether SLNB after NACT is safe.

Keywords: Breast cancer, neoadjuvant chemotherapy, timing sentinel lymph node biopsy

Citation Format: Delameilleure M, Smeets A, Nevelsteen I, Han S, Van Nieuwenhuysen E, Berteloot P, Hoste G, Salihi R, Van Ongeval C, Keupers M, Prevos R, Wildiers H, Punie K, Van Limbergen E, Weltens C, Janssen H, Floris G, Vergote I, Neven P. Monocentric experience with the sentinel lymph node biopsy prior to neoadjuvant chemotherapy in clinically lymph node negative early breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-32.

Abstract P4-02-07: Comparison of breast cancer molecular subtyping by Immunohistochemistry and by BluePrint® next generation RNA sequencing-based test at University Hospitals Leuven and Curie Institute Paris

Background

MammaPrint® (MP) and BluePrint® (BP) are microarray-based tests with MP being prognostic for distant recurrence and BP enabling stratification into breast cancer molecular subtypes (Luminal, HER2, Basal-type). Recently, a CE marked MP and BP targeted RNA Next Generation Sequencing (NGS)-based kit was developed at Agendia and validated at University Hospitals Leuven and Curie Institute Paris. Here we compare breast cancer molecular subtype stratification defined by immunohistochemistry (IHC) and by MP and BP NGS- and microarray- based tests.

Patients and Methods

In this study, 124 primary operable invasive breast cancer patients were included at University Hospitals Leuven and at Curie Institute (n=80 Leuven; n=44 Curie) with the following histological subtypes: ductal-NOS (n=100), lobular (n=16), mucinous (n=3), tubular (n=2), others (n=3). Patients with bilateral breast cancer or with &gt;3 positive lymph nodes were excluded. Surrogate breast cancer subtypes based on IHC were defined as follows: luminal if ≥10% estrogen receptor (ER) expression; triple negative if &lt;10% ER and progesterone receptor (PR) expression and HER2 stained negative by IHC and/or FISH; HER2+ if HER2 receptor stained positive (2+ or 3+) by IHC and/or FISH. Luminal subtypes were further stratified into Luminal A-like (HER2 negative, Ki-67&lt;14%, PR≥20%) and Luminal B-like (HER2 negative or positive, Ki-67 ≥14%, PR&lt;20%). When Ki-67% was not available, tumors with grade 1 or 2 were classified as Luminal A-like and with grade 3 as Luminal B-like. IHC subtypes were compared to the BP NGS and microarray molecular subtypes (Luminal-, HER2- and Basal-type). To further stratify BP luminal type tumors, MP test was used as follows: Luminal A (BP Luminal and MP low risk) and Luminal B (BP Luminal and MP high risk).

Results

Concordance between IHC and MP/BP NGS subtyping was 75.0% (93/124), while concordance between MP/BP on NGS and microarray was 89.5% (111/124). MP/BP NGS subtyping identified more low risk Luminal A tumors compared to IHC (54.0%, (67/124) vs 44.3% (55/124)). Notably, concordance was excellent for triple-negative and, to less extent for HER2 driven tumors (Luminal B-like-HER2 positive and HER2+).

IHC vs. MP/BP NGS molecular subtyping (n=124)  MP/BP NGSIHCLuminal ALuminal BHER2-positiveBasalTotalLuminal A-like4690055Luminal B-like, HER2-negative16210037Luminal B-like, HER2-positive565016HER2-positive00303Triple negative0101213Total6737812124Microarray vs MP/BP NGS molecular subtyping (n=124)  MP/BP NGSMicroarrayLuminal ALuminal BHER2 positiveBasalTotalLuminal A6040064Luminal B7310038HER2-positive028010Basal0001212Total6737812124

Conclusion

This study shows a discordance of 25.0% between IHC and BP/MP NGS subtyping. This is in line with previous findings where IHC was compared to molecular subtyping based on microarray (Viale 2017, Whitworth 2014) underlining the complementarity of genomic testing in early stage breast cancer. Moreover, we observed a high concordance between NGS and microarray molecular subtyping, which suggests a successful translation of the MP/BP microarray test to a MP/BP NGS test.

Citation Format: Darrigues L, Slembrouck L, Mittempergher L, Delahaye LJ, Vanden Bempt I, Vander Borght S, Vliegen L, Sintubin P, Raynal V, Bohec M, Reyes C, Rapinat A, Helsmoortel C, Jongen L, Hoste G, Neven P, Wildiers H, Smeets A, Nevelsteen I, Punie K, Van Nieuwenhuysen E, Han S, Laurent C, Vincent-Salomon A, Laas-Faron E, Witteveen AT, Neijenhuis S, Glas AM, Floris G, Reyal F. Comparison of breast cancer molecular subtyping by Immunohistochemistry and by BluePrint® next generation RNA sequencing-based test at University Hospitals Leuven and Curie Institute Paris [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-02-07.

Abstract P4-08-25: Decentralized beta testing of MammaPrint and BluePrint NGS kit at University Hospitals Leuven and Curie Institute Paris

Background

Many countries restrict patient material exchange to central diagnostic laboratories abroad, limiting access to assays like MammaPrint® (MP) and BluePrint® (BP). Both assays are microarray-based, with MP being prognostic for distant recurrence and BP for molecular subtyping of breast cancer (Luminal-, HER2-, and Basal-type). To increase accessibility, decentralization is required with Next Generation Sequencing (NGS) being the preferred testing platform given that most diagnostic laboratories have the technology in place. The aim of this beta testing study is to validate a previously developed and centrally validated MP and BP NGS kit for RNA samples in two large tertiary academic hospitals in Europe.

Patients and Methods

Patients with early breast cancer diagnosed at the Multidisciplinary Breast Center at University Hospitals Leuven and Curie Institute Paris were prospectively included between September 2017 and January 2018. Patients with bilateral breast cancer or presenting with more than 3 positive lymph nodes were excluded. Only patients with invasive ductal and invasive lobular carcinoma were included. Twenty tissue sections were cut from formalin-fixed, paraffin-embedded (FFPE) blocks; 10 tissue sections were analyzed at the local site using the MP and BP NGS kit, and 10 tissue sections were analyzed at Agendia using the same kit and procedure, as well as with the golden standard method (gene expression microarrays). Targeted RNA sequencing of the 70 MP and 80 BP signature genes was performed on Illumina MiSeq instruments. The raw NGS data generated at the local test sites was sent through a secure file transfer protocol server to Agendia for interpretation and comparison with microarray and NGS performed in the Agendia laboratories. We aimed for a minimum concordance rate between MP and BP outcome of 90% between each local site and Agendia's centralized site.

Results

In this study, 116 early breast cancer patients were included (73 from University Hospitals Leuven and 43 from Curie Institute). Out of these patients, 52% were MP Low Risk and 48% MP High Risk according to microarray. The patients had a BP luminal, HER2 or basal subtype in respectively 83%, 9% and 8%. Concordance between MP microarray obtained from Agendia and MP NGS obtained from the local sites was 91.4%. Concordance between MP High and Low Risk classification between NGS Leuven versus NGS Agendia was 92.1% and between NGS Curie versus NGS Agendia 95.3%. For BP subtype outcomes, the results from microarray versus NGS for all patients combined from both local sites gave a 98.3% concordance and NGS Agendia versus NGS from each local site gave a 100% concordance.

Conclusion

The MP and BP NGS kit was successfully validated in a decentralized setting, showing high concordance between results obtained at three different sites. There was a clear benefit of having well-trained NGS experienced diagnostic technical teams. The MP and BP NGS kit the first FFPE targeted RNA sequencing based multigene signature for breast cancer care, will provide a high and equal standard of MP and BP gene expression testing for breast cancer in a decentralized setting.

Citation Format: Slembrouck L, Laurent C, Delahaye LJ, Mittempergher L, Vanden Bempt I, Vander Borght S, Darrigues L, Vliegen L, Sintubin P, Raynal V, Bohec M, Reyes C, Rapinat A, Helsmoortel C, Jongen L, Hoste G, Neven P, Wildiers H, Smeets A, Nevelsteen I, Punie K, Van Nieuwenhuysen E, Han S, Salomon AV, Faron EL, Cynober T, Witteveen AT, Neijenhuis S, Glas AM, Reyal F, Floris G. Decentralized beta testing of MammaPrint and BluePrint NGS kit at University Hospitals Leuven and Curie Institute Paris [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-25.

Abstract P1-15-04: Breast cancer recurrence and predictors for recurrence despite pathologic complete response following neoadjuvant chemotherapy

Introduction

Breast cancer patients with a high-risk tumor (for example Triple Negative Breast Cancer) who achieve a pathological complete response (pCR) following neoadjuvant chemotherapy (NACT) have a better outcome compared to patients with residual disease at surgery. This study investigated Breast Cancer Free Survival (BCFS) and predictors for distant relapse despite pCR.

Methods

Monocentric retrospective study of 243 consecutive breast cancer patients who achieved pCR (ypT0/is ypN0/N0(i+)) after treatment with NACT in UZ Leuven between 01/2000 and 08/2017. 58% had stage III breast cancer, 40% Triple Negative Breast Cancer (TNBC) and 47% HER2 pos breast cancer. BCFS was defined as any breast cancer related event (local, contra-lateral, regional, metastatic) that first appeared. Primary endpoints were frequency of BCFS and predictors for metastatic relapse: patient demographics (age, body mass index (BMI)) and tumor characteristics (TNM stage, histological type, hormonal receptor status). Secondary endpoints were breast cancer specific survival (BCSS) and overall survival (OS). Statistical analysis was performed using the Statistical Package for the Social Sciences software (SPSS, version 25). The Kaplan Meier method was used for survival analysis.

Results

Of 1167 breast cancer patients undergoing neoadjuvant treatment, 243 patients (20,8%) achieved pCR and were included. Median follow up was 57 months (range 9-252 months). 22 (9.1%) developed tumor progression; 20 (8.2%) metastatic and 2 (0.8%) contralateral. First metastatic site was the brain in 11/20 patients (55%) and 14/22 (64%) died of breast cancer. Higher clinical tumor stage at diagnosis predicted metastatic relapse (stage I-II 2.9%; stage III 12.1%). Patients with a BMI ≤25 kg/m2 had less metastatic relapse than patients with BMI &gt;25kg/m2 (3.8% versus 12.0%), better OS (94.6% vs 88.0%) and BCSS (97.7 vs 91.7%). Neither tumor type (TNBC 8.2%; HER2-pos 8.1%; HR-pos/HER2 neg 9.3%) nor younger age &lt; 36yrs (3.3% versus 8.9%) was prognostic for post-pCR relapse. There is a lower OS (mean 174m versus 231m, 95% CI 158-190m, median 208m) and BCSS (mean 191m versus 253m, 95% CI 182-200m) in cN1-3 versus cN0 disease at diagnosis.

Conclusion

Despite NACT-induced pCR, a small proportion (9.1%) will develop a metastatic relapse after a median follow-up of 57 months. We found that a higher stage at diagnosis and a higher BMI were prognostic for worse BCFS while age &lt;36 y and negative hormonal receptor status were not prognostic. cN+ at diagnosis and a BMI &gt;25 predict worse OS and BCSS.

Citation Format: Borremans K, Berteloot P, Van Nieuwenhuysen E, Han S, Hoste G, Wildiers H, Punie K, Smeets A, Nevelsteen I, Floris G, Van Ongeval C, Keupers M, Prevos R, Van Limbergen E, Menten J, Weltens C, Janssen H, Vergote I, Neven P. Breast cancer recurrence and predictors for recurrence despite pathologic complete response following neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-15-04.

Abstract P5-09-05: Hereditary breast cancer beyond BRCA: Clinical and histopathological characteristics in patients with germline CHEK2, ATM, PALB2 and TP53-mutations

Background

The introduction of multi-gene panel testing in the diagnosis of hereditary breast and ovarian cancer (HBOC) has led to an important increase in the detection of breast cancer predisposition genes other than BRCA1 and BRCA2.

Methods

All individuals who underwent HBOC-testing at our institution since the introduction of multi-gene panel testing were included (March 2016-August 2017). In this retrospective analysis, the BRCA Hereditary Cancer MASTR Plus® panel is used (Multiplicom, Belgium), with sequencing of BARD1, BRCA1, BRCA2, BRIP1, RAD51C, RAD51D, TP53, MRE11A, RAD50, NBN, FAM175A, ATM, PALB2, STK11, MEN1, PTEN, CDH1, MUTYH, CHEK2, BLM, XRCC2, EPCAM, MLH1, MSH6, PMS2, MSH2.

In breast cancer patients with a recurrent germline alteration, age and TNM stage at diagnosis, histological subtype, grade of differentiation and molecular surrogate subtype were recorded. Given the low numbers of TP53-carriers diagnosed by HBOC testing, also patients with a germline TP53-mutation diagnosed by targeted sequencing at our institution were included. Statistical analysis were performed with SPSS version 25.

Results

In 11.9 % of 2806 patients who underwent panel testing, a germline pathogenic alteration was detected. BRCA1 and BRCA2 were the most prevalent alterations, detected in respectively 3.35 and 2.92 % of patients. Germline alterations in CHEK2, ATM , PALB2 and TP53 were detected in respectively 2.5 %, 1.1 %, 0.5 % and 0.1 %. In 1 % of patients, germline alterations were retrieved that only contribute to ovarian cancer risk (BRIP, RAD51C, RAD51D). Germline DNA mismatch repair alterations were detected in 0.39 % of patients.

The median age at onset of breast cancer in patients with germline CHEK2-, ATM-, PALB2- and TP53-mutations was 47, 53, 39 and 33 years respectively. The age of breast cancer diagnosis in patients with germline TP53-alterations was significantly younger compared to patients with CHEK2-mutations (p = 0.01), ATM-mutations (p = 0.01) and PALB2-mutations (p = 0.04). In situ carcinomas were diagnosed in respectively 9 %, 11 % and 11 % of patients with CHEK2-, PALB2- and TP53-mutations. Patients with CHEK2, ATM, PALB2 and TP53-alterations were diagnosed with ≥T3-tumors in respectively 13 %, 12 %, 33 % and 22 %. Nodal status at diagnosis was negative in 40-60 % in these 4 subgroups. Upfront metastatic disease was diagnosed only in 2/43 CHEK2-carriers. More than half of the breast cancer diagnoses were luminal tumors in CHEK2-, ATM- and PALB2-carriers, while cases with germline TP53-alterations only presented with luminal cancers in 22 % in our series.

Conclusion

Almost half of the pathogenic mutations detected in HBOC-genes are alterations in genes other than BRCA1 and BRCA2. CHEK2-mutations are by far the most prevalent, followed by ATM, PALB2 and TP53.

The range of the CHEK2- and ATM-population was wider then expected at the lower-age boundary. The age of breast cancer diagnosis in patients with germline TP53-mutations was significantly younger compared to patients with CHEK2-, ATM- and PALB2-mutations. The distribution of the histological subtypes and grade of differentiation was not suggestive of a specific correlation with germline mutation status.

Citation Format: Hoste G, D'Hoore P, Legius E, Van Buggenhout G, Floris G, Wildiers H, Han SN, Van Nieuwenhuysen E, Berteloot P, Smeets A, Nevelsteen I, Weltens C, Janssen H, Van Limbergen E, Neven P, Punie K. Hereditary breast cancer beyond BRCA: Clinical and histopathological characteristics in patients with germline CHEK2, ATM, PALB2 and TP53-mutations [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-09-05.

Palbociclib in highly pretreated metastatic ER-positive HER2-negative breast cancer

PURPOSE

We aimed to investigate the role of palbociclib, a first-in-class cyclin-dependent kinase 4 and 6 inhibitor, in postmenopausal women with highly pretreated endocrine therapy-resistant metastatic breast cancer (MBC).

METHODS

Between 28 September 2015 and 14 March 2017, a compassionate use program was established in the University Hospitals Leuven in which 82 postmenopausal women with estrogen receptor-positive, HER2-negative MBC were included after at least four lines of systemic treatment. The efficacy and safety analysis was performed in 82 patients who had received at least one dose of palbociclib and who had at least 6-month follow-up at the data cut-off point. The primary objective was the evaluation of efficacy of the combination of palbociclib and endocrine therapy with clinical benefit as primary endpoint, defined as the absence of progressive disease and being on treatment for at least 6 months. Secondary objectives were the evaluation of toxicity and the identification of potential predictors for clinical benefit.

RESULTS

The median age of the patients was 67.1 years (range 34.8-85.9) at the time of inclusion. The average duration of treatment was 5.6 months (range 1-19), with a median progression-free survival of 3.17 (95% CI 2.76-4.70) months. At the data cut-off point, 10 patients were still on treatment with palbociclib. In this highly pretreated setting, 34 patients experienced no progressive disease within 6 months, resulting in an overall clinical benefit rate (CBR) of 41.5%. 20.7% (17/82) showed stable disease for ≥ 9 months and 13.4% for ≥ 12 months. None of the investigated predicting factors were significantly associated with clinical benefit at 6 months. For 43.9% of the patients, treatment delay or dose reduction was indicated.

CONCLUSIONS

Palbociclib in combination with endocrine therapy shows an unexpectedly high CBR and favorable safety profile in heavily pretreated endocrine-resistant estrogen receptor-positive, HER2-negative MBC patients.

Abstract P5-21-22: Palbociclib in highly pretreated metastatic ER-positive HER-2 negative breast cancer

Palbociclib, a first-in-class CDK 4/6 inhibitor, in combination with letrozole or fulvestrant is now licensed for the first or second line treatment of postmenopausal women with hormone-sensitive HER-2 negative metastatic breast cancer (MBC), but its activity in later lines is unknown. In Belgium, a compassionate Use Program (CUP) was temporarily established to provide palbociclib after at least 4 lines of systemic treatment for MBC.

The UZ Leuven Multidisciplinary Breast Center included 82 patients in this CUP from September 28th 2015 to March 14th 2017. This analysis describes retrospectively collected efficacy (Revised RECIST guideline, version 1.1) and safety data from 68 patients with at least 6 months follow-up at the data cut-off point. The primary endpoint was clinical benefit, defined as being on treatment for at least 6 months (CR + PR + SD). Most of the patients (89.7%) used palbociclib in combination with letrozole. Other combinations are with tamoxifen (2.9%), fulvestrant (2.9%), exemestane (1.5%), anastrazole (1.5%) and megestrol (1.5%).

At the data cut-off point, 18 patients are still on-treatment with palbociclib. The average duration of treatment is 5.7 months [range 2m- 17m]. The mean age of the patients was 66.3 years [range 34.8y – 85.9y] at the time of inclusion. Patients had had an average of 5.7 lines of systemic therapy [range 4 – 11 lines] before starting palbociclib, which was in 61.8% at least one line of chemotherapy. In this highly pretreated setting, 29 patients experienced stable disease lasting ≥ 6 months, resulting in an overall clinical benefit rate of 42.6%. 19.1% (13/68) showed stable disease for ≥ 9 months and 8% for ≥ 12 months. The subjective tolerance of the combination treatment was good, with 38% (26/68) of the patients discontinuing or delaying treatment following adverse events which were in the vast majority hematologic but asymptomatic. No factors predicting clinical benefit could be identified: use of chemotherapy before starting Palbociclib (p = 0.4644), age (p = 0.7029), time between primary breast cancer diagnosis and starting palbociclib (p = 0.1919) or time between first metastasis and starting palbociclib (p = 0.1108) and bone-only disease (p = 1,0000) were not significantly associated with clinical benefit at 6 months.

These data not only support the findings of the PALOMA studies, but also show unexpectedly high clinical benefit and safety of palbociclib in heavily pretreated endocrine-resistant hormone receptor positive HER-2 negative advanced breast cancer.

An update of these data will be presented.

Citation Format: Hoste G, Punie K, Wildiers H, Neven P, Berteloot P, Van Nieuwenhuysen E, Han S, Concin N, Salihi R, Lefever I, Vergote I. Palbociclib in highly pretreated metastatic ER-positive HER-2 negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-22.

Abstract P5-14-06: The effect of adjuvant chemotherapy in a large consecutive series of ER-pos HER-2 negative early breast cancers

Background: The last EBCTCG-overview reported, in general, a significant better breast cancer outcome if adjuvant chemotherapy was added to surgery and endocrine therapy in ER-pos breast cancers, but the precise indication for adjuvant chemotherapy in this population remains controversial. We study the effect of adjuvant chemotherapy on breast cancer outcome in consecutive patients with an ER-pos HER-2 negative breast cancer treated with adjuvant antihormonal therapy.

Methods: Data were collected prospectively from consecutive patients with non-metastatic breast cancer that were primary operated between 2000 and 2012 at the University Hospitals Leuven (Belgium). A Propensity Score (PS) weighted analysis was performed to estimate the average treatment effect (ATE). The primary endpoint was recurrence free interval (RFI). Secondary endpoints were distant recurrence free interval (D-RFI) and breast cancer specific survival (BCSS). Covariates used to generate the propensity score and to include in the PS weighted analysis were age at diagnosis, body mass index, tumor size, grade, pN, lymph vessel invasion, PR, and radiotherapy. Cause-specific hazard models were fitted, using death not from breast cancer as competing risk. Treatment heterogeneity was examined by evaluating interactions of each covariate with adjuvant chemotherapy, using the Bonferroni-Holm method to correct for multiple testing.

Results: In the total cohort of 5609 patients, 4282 had a hormone sensitive HER-2 neg breast cancer and 4121 (96.2%) of these received adjuvant antihormonal therapy. Adjuvant chemotherapy was given in 1179/4121 patients (29%). Median follow-up was 8.5 years. Due to very strong differences between patients with and without adjuvant chemotherapy, a restricted PS weighted analysis was used according to a recent recommendation in the statistical literature. This analysis is based on 1750 patients with a PS between 0.1 and 0.9. In this group, 807 (46%) received adjuvant chemotherapy, 211 (12%) observed an event for RFI, 167 (10%) for D-RFI, and 108 (6%) for BCSS. Adjuvant chemotherapy was associated with better prognosis: the adjusted cumulative incidence of recurrence within 5 years was 9.7% without and 5.3% with adjuvant chemotherapy. The adjusted hazard ratio for RFI was 0.50 (95% CI 0.33-0.74). There were no strong interactions with adjuvant chemotherapy. Results for D-RFI and BCSS were similar.

Conclusion: Based on PS analysis to reduce confounding and chemotherapy indication bias, we observed clear benefit from adjuvant chemotherapy in ER-pos HER-2 negative breast cancers.

Citation Format: Van Calster B, Neven P, Wildiers H, Punie K, Jongen L, Han S, Berteloot P, Van Nieuwenhuysen E, Nevelsteen I, Smeets A, Floris G. The effect of adjuvant chemotherapy in a large consecutive series of ER-pos HER-2 negative early breast cancers [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-14-06.

Abstract P6-09-32: The association of breast cancer subtype and breast cancer survival with parity and time since last birth

Background: Pregnancy affects breast cancer risk but it's influence on breast cancer subtype and prognosis remains controversial. We studied the effect of parity and time since last birth on breast cancer subtype and outcome in women aged ≤50 years at diagnosis.

Patients and Methods: A retrospective multivariate cohort study including all premenopausal women aged ≤50 years (N=1306) at diagnosis and primarily treated with surgery (N=1176) or neo-adjuvant chemotherapy (N=130) at University Hospitals Leuven (Jan. 2000 – Dec. 2009); local and systemic therapies were consistent with guidelines when treated. Tumor subtypes were defined by tumor grade and receptor expression for estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER-2) amplification; ER+PR+/-HER-2- cases were Luminal A- like if grade 1-2 and Luminal B like if grade 3; HER-2+ cases were Luminal HER-2 if ER+ and HER-2 like if ER-; triple negative breast cancer (TNBC) were ER-PR-HER-2-. Outcome endpoints were breast cancer subtype, disease free (DFS) and distant disease free survival (DDFS) by parity and in parous women comparing short (&lt;5 years) versus long (≥5 years) time since last birth. Statistics used were Cox proportional hazard model. Results were corrected for age at diagnosis, tumor size, lymph node status and tumor subtype.

Results: Breast cancer subtypes didn't differ between nulliparous and parous women but subtypes differed significantly in parous women by time interval since last birth (p&lt;0.001). Breast cancers within 5 years of last birth were proportionally more likely TNBC and HER-2 like compared to Luminal A (p=0.026 and p=0.003 respectively) than breast cancers ≥5 years after last birth even when corrected for age at diagnosis. After a mean follow-up period of 10 years, parous women had a better DFS compared to nulliparous women (DFS: HR 0.754; CI 0.593-0.959; p=0.021) but after correction for known prognostic factors, only a trend remained (HR 0.783; CI 0.611-1.004; p=0.054). In parous women, those with a longer time interval since last birth had a better DFS than women with a recent pregnancy (HR 0.965; CI 0.948-0.982; p&lt;0.001). However, after correction for known prognostic factors, this association was completely attenuated (HR 0.997; CI 0.972-1.023; p=0.828). Comparable results were seen for DDFS.

Conclusion: After correction for age at diagnosis, parity does not but recent birth does affect breast cancer subtype. Such tumors are proportionally more likely ER-negative namely TNBC and HER-2 like. We observed a trend for better DFS for parous women. The prognostic value of time since last birth is mostly due to tumor characteristics and age at time of diagnosis.

Citation Format: De Mulder H, Laenen A, Wildiers H, Punie K, Poppe A, Remmerie C, Nevelsteen I, Smeets A, Van Nieuwenhuysen E, Van Limbergen E, Floris G, Vergote I, Neven P. The association of breast cancer subtype and breast cancer survival with parity and time since last birth [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-09-32.

Ovarian cancer in children and adolescents: A rare disease that needs more attention

Ovarian cancer is rare in childhood. This explains why there are only scattered reports on it in the literature and why there is a lack of specific pediatric treatment. This paper gives an overview of the Belgian data from 2004 to 2013 and reviews the literature. To index ovarian masses and malignancies in children better in the future, worldwide data collection should be improved and reproducible definitions of 'childhood', 'malignancy' and 'ovarian mass' need to be adopted.

Obesity and survival among women with ovarian cancer: results from the Ovarian Cancer Association Consortium

Background:

Observational studies have reported a modest association between obesity and risk of ovarian cancer; however, whether it is also associated with survival and whether this association varies for the different histologic subtypes are not clear. We undertook an international collaborative analysis to assess the association between body mass index (BMI), assessed shortly before diagnosis, progression-free survival (PFS), ovarian cancer-specific survival and overall survival (OS) among women with invasive ovarian cancer.

Methods:

We used original data from 21 studies, which included 12 390 women with ovarian carcinoma. We combined study-specific adjusted hazard ratios (HRs) using random-effects models to estimate pooled HRs (pHR). We further explored associations by histologic subtype.

Results:

Overall, 6715 (54%) deaths occurred during follow-up. A significant OS disadvantage was observed for women who were obese (BMI: 30–34.9, pHR: 1.10 (95% confidence intervals (CIs): 0.99–1.23); BMI: ⩾35, pHR: 1.12 (95% CI: 1.01–1.25)). Results were similar for PFS and ovarian cancer-specific survival. In analyses stratified by histologic subtype, associations were strongest for women with low-grade serous (pHR: 1.12 per 5 kg m⁻²) and endometrioid subtypes (pHR: 1.08 per 5 kg m⁻²), and more modest for the high-grade serous (pHR: 1.04 per 5 kg m⁻²) subtype, but only the association with high-grade serous cancers was significant.

Conclusions:

Higher BMI is associated with adverse survival among the majority of women with ovarian cancer.