Leeuwen-Stok, E van

Abstract Introduction. Male breast cancer (male BC) is a rare disease for which disease management is extrapolated from females. IMBC, an international consortium, which previously reported on clinico-pathological aspects, now reports on molecular subgroups revealed by RNA sequencing and their relation to patient outcome. Methods. Tumor samples from the retrospective MALE BC registry diagnosed between 1990-2010 and with pathology and outcome data (relapse-free- (RFS) and overall survival (OS)) were included (n=699). To allow the discovery of prognostic features, we selected, stratified for known risk factors (TN stage, grade, age at diagnose and adjuvant endocrine treatment), from the cohort 152 cases with poor (RFS <= 4 yrs) and good outcome (RFS > 7yrs) evenly distributed. Here, we report RNA sequencing results of the first 73 cases, 38 with poor and 35 with good outcome. RNA sequencing reads were used to generate gene expression values and to report transcripts carrying driver mutations. Unsupervised clustering identified subgroups and within subgroups differentially expressed genes were identified. The reported prognostic male BC subgroups M1 and M2 (Johansson BCR 2012(14):R31) were also annotated. All identified subgroups were related to outcome using logistic regression (p-value using Wald test). Results. Unsupervised clustering revealed 2 main subgroups of which group 1 was enriched for expression of ER target genes, WNT3 and genes from amplicons known for female BC, e.g. 19p13 (CCNE1), 8q24 (MYC), and 11q13 (CCND1). The biology of the smaller group 2 was less defined but TGFβ2 expression was high as were various kallikreins (KLK) including interestingly KLK3 (prostate specific antigen). Other known amplified regions [(8p11 (FGFR1), 20q13 (ZNF217) and 12q15 (MDM2)] and mutated transcripts [PIK3CA (H1047R/L/Q; E542K, E545K, N345K; 16% of cases), TP53 and SF3B1 (K700E) (2% of cases)] were identified. Profound tumor infiltrate gene expression was present in 5% of cases and one third of cases expressed proliferation markers. Except for TP53, none of these latter characteristics were unevenly distributed among the 2 main subgroups. ER and AR were highly correlated, particularly in group 1. The two main groups could be further subdivided. Group 1 comprised 3 subgroups of which subgroup 1a expressed TFF1/3 and NAT1, well-known ER targets, while subgroups 1b and 1c expressed other ER targets,respectively BEX1 and PITX1. HOXC cluster expression differentiated subgroup 1b from 1a and 1c. None of these intrinsic subgroups were, however, related to RFS. The previously reported M2 subgroup, which largely segregated with subclusters 1a and 1b, was associated with a better RFS than the M1 subgroup (OR=2.9; 95%CI 1.1-7.5; p-value=0.03). Conclusions. 1) Intrinsic subtypes of male BC were revealed and their subgrouping is defined by ER associated subsets of genes. 2) The association of the reported M2 subgroup of male BC with longer RFS was validated; 3) Currently identified biological characteristics of male BC may improve future treatments. The full report on 152 cases including a comparison to female BC will be presented at the conference. This research was funded by Breast Cancer Research Foundation Citation Format: Martens JWM, Sieuwerts A, Ponchet C, Smid M, de Weerd V, Slaets L, Piper T, van Deurzen CHM, Schroder CP, Stangle C, Kloosterman W, van Leeuwen-Stok E, Nilsson C, Vermeij J, Peeters S, Goulioti T, Nowaczyk M, Aebi S, Rubio IT, Kelly C, Bayani J, Porter P, Murray M, Hudis C, Middleton L, Korde L, Ruddy K, Winer E, Bogler O, van den Weyngaert D, dal Lago L, Fraser J, Benstead K, van Asperen C, Linderholm B, Hedenfalk I, Tryfonidis K, Giordano S, Bartlett J, Cardoso F. Molecular subtyping of male breast cancer by the International male breast cancer program (IMBC): EORTC 10085/TBCRC 0-29/BIG 2-07/NABCG/BOOG 2009-04 [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 PD7-12.

Abstract Introduction: Male BC is a rare disease (dx) for which management is extrapolated from trials in female BC. Comprehensive prospective data about QoL in men with BC could inform treatment. The international Male BC Consortium conducted a prospective registry of male BC patients of all stages who newly presented to a participating center between October 2013 and February 2017. A QoL substudy was conducted as part of this registry at most participating sites. Methods: Informed consent for participation in the QoL substudy was requested from new enrollees. Those who consented were asked to complete a survey including the EORTC QLQ-C30 and BR23 (breast cancer specific module), adapted by replacing female-specific items with male-specific sexual activity/function items from the prostate module (PR25). Outcomes were scored according to standard EORTC QLQ procedures on a 0-100 scale (with higher scores on QoL/functioning scales representing better QoL and functioning, and higher scores on symptom scales representing worse symptoms). Forms were analyzed centrally by EORTC. In order to compare to female BC, we used reference data from 2782 mixed age (62% under age 60) women with BC (of whom 1,147 had recurrent or metastatic dx, and 464 had stage 1-2 dx) reported in the EORTC QLQ-C30 Reference Values manual (2008). Results: A total of 557 men were enrolled in EORTC10085, 445 at sites participating in the QoL substudy. Consent forms were received from 422/445 (95%) for the substudy. Baseline survey (required to be completed within 30 days of enrollment) compliance was 85% (359/422). Median age at diagnosis was 67 years. There were 111 men (45%) with node-positive M0/MX dx and 27 men (8%) with M1 dx. Their median global health status score at baseline was 75 (IQR 67-83), higher than that documented historically in female BC (67, with IQR 50-83, in both the 2782 women with mixed stage and the subgroup of 464 with stage 1-2 tumors). The participating men's median social functioning score was 100 (IQR 67-100), also higher than the 83.3 (IQR 67-100) reported in mixed stage female BC patients, though no different than the 100 (IQR 67-100) found in women with stage 1-2 dx. Men's most commonly reported symptoms included fatigue (median score 13.9, IQR 0-33), insomnia (median score 0, IQR 0-33), and pain (median score 0, IQR 0-33), for which women's median scores were 33 (IQR 11-44), 33 (IQR 0-33), and 17 (IQR 0-50) with mixed stage dx, and 22 (IQR 0-33), 33 (IQR 0-33), and 17 (IQR 0-33) with stage 1-2 dx. Men's median sexual activity score was 33.3 (IQR 0-50), with less sexual activity reported by older patients and men with M1 dx. In those who were sexually active, median sexual function score was 83 (IQR 75-92), with no difference by age or stage. Conclusions: QoL and symptom burden in male BC patients appears no worse (and possibly better) than that in female patients. Future analyses of 1- and 5-year surveys from this study will assess the impact of specific treatments on changes in symptoms and QoL over time. These data will be useful in future efforts to tailor treatments and target interventions for male BC. Funding: Breast Cancer Research Foundation, Dutch Pink Ribbon Foundation, Swedish BRO, and EBCC Council. Citation Format: Schroder C, Cardoso F, Dijkstra N, van Leeuwen-Stok E, Linderholm B, Morgenstern D, Van Poznak C, Wolff AC, Poncet C, Gomez HL, Aalders K, Bjelic-Radisic V, Werutsky G, Tryfonidis K, Coens C, Giordano SH, Ruddy KJ. Quality of life (QoL) in male breast cancer (BC): Prospective study of the EORTC10085/TBCRC029/BIG2-07/NABCG International male BC program [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 P5-23-02.