Collins, Laura C.

Abstract Background Young women are more likely than older women to present with higher stage breast cancer (BC) and may benefit to a greater extent from downstaging with neoadjuvant systemic treatment (NST). Young age is also associated with greater likelihood of pathologic complete response (pCR). Using a large prospective cohort of young women with BC, we investigated response to neoadjuvant therapy, eligibility for breast conserving surgery (BCS) pre- and post-NST, and surgical treatment. Methods The Young Women's Breast Cancer Study (YWS) is a multi-center cohort of women diagnosed with BC at age ≤40, that enrolled 1302 patients from 2006 to 2016. Disease characteristics and treatment information were obtained through medical record and central pathology review. Surgical recommendation before and after NST, conversion from BCS borderline/ineligible to BCS eligible, surgery, documented reasons for choosing mastectomy (MTX) among BCS eligible women, and final pathologic response were independently reviewed. Results Among 1302 women enrolled in YWS, 801 (62%) presented with unilateral stage I-III breast cancer and 317(40%) received NST. Median age was 36 years old (22-40). Pre-NST, 85/317 (27%) were BCS eligible, 49 (15%) were borderline, and 169 (53%) were not eligible (16 inflammatory breast cancer (IBC), 88 large tumor size /cosmetic, 48 diffuse calcifications, and 83 multicentricity). Among the 218 patients who were BCS ineligible/borderline pre-NST, 82 (38%) became eligible for BCS after NST. 4 patients who were BCS eligible pre-NST became ineligible. Of all patients eligible for BCS post-NST (n=163), 80 (49%) attempted BCS, 74 (93%) of whom were successful, and 83 (51%) chose MTX. Reasons for choosing MTX included: patient preference (38/83 (46%)), BRCA or TP53 mutation (31 (37%)), family history (3 (4%)), unknown (11 (13%)). On final pathology, 75 (24%) patients had pCR. Among patients who achieved a pCR, 48 (64%) underwent MTX, fewer than half (21/48 (44%)) were for anatomic indications (IBC, large tumor at diagnosis, diffuse calcifications, multicentric disease). Conclusion While NST doubled the proportion of young women eligible for BCS, nearly half chose MTX regardless of response to NST, mostly for personal preference or high-risk preventative reasons. These data highlight that surgical decision making among young women with breast cancer is often driven by factors beyond extent of disease and clinical response to therapy. Table 1.Clinical-pathologic characteristicsCharacteristicsNumber%Pre NST surgical recommendation BCS eligible8526.8Borderline4915.5BCS ineligible16953.3Unknown144.4Clinical Response Complete20263.7Partial9229.0Stable30.9Progressing72.2Unknown134.1Pathologic Response pCR (No invasive or DCIS)7524No pCR24276Post NST Surgical recommendation BCS eligible16351.4BCS ineligible14445.4Unknown103.2Attempted surgery BCS8025.2MTX23674.1Unknown20.6Final Surgery BCS7423.3MTX24176unknown20.6 Citation Format: Kim HJ, Dominici L, Rosenberg S, Pak LM, Poorvu PD, Ruddy K, Tamimi R, Schapira L, Come S, Peppercorn J, Borges V, Warner E, Vardeh H, Collins L, King T, Partridge A. Surgical treatment after neoadjuvant systemic therapy in young women with breast cancer: Results from a prospective cohort study [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 GS6-01.

Abstract Background: This analysis aimed to determine if associations of prediagnostic mammographic percent breast density, absolute dense area, and absolute non-dense area and risk of breast cancer vary according to the subsequent breast tumors biomarker status. Methods: We included 1,154 postmenopausal women diagnosed with breast cancer between June 1, 1989, and June 30, 2004, and 2,078 matched controls from the Nurses' Health Study I and II. Percent breast density, absolute dense and non-dense areas were estimated from digitized film mammograms using computer assisted thresholding techniques. Density measures were modeled as quartiles. Information on estrogen receptor (ESR1 [ER]), progesterone receptor (PGR [PR]), and human epidermal growth factor receptor 2 (ERBB2 [HER2]) status was obtained from pathology reports and medical records, and if missing, from immunostains performed on paraffin sections of tumor tissue microarrays (TMAs). Other biomarkers assessed on TMAs were androgen receptor (AR), cytokines 5/6 (KRT5/KRT6 [CK5/6]), epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGFA [VEGF]), and cyclooxygenase 2 (PTGS2 [COX2]). Information on breast cancer risk factors was obtained prospectively from biennial questionnaires before the date of cancer diagnosis for cases and matched controls. Polychotomous logistic regression was used to assess associations of the three breast density measures with tumor subtypes based on the status of selected tissue markers. Results: Breast cancer risk was positively associated with percent density and absolute dense area and inversely associated with absolute non-dense area (p for trend<0.0001 for all). The associations of percent density with breast cancer risk did not statistically significantly differ by the status of any of the markers. However, we found stronger positive associations for absolute dense area and KRT5/KRT6- and EGFR- tumors as compared to respective marker-positive tumors (4th vs. 1st quartile: OR=2.99 for KRT5/KRT6- vs. OR=0.92 for KRT5/KRT6+ tumors, p-heterogeneity <0.001; OR=3.06 for EGFR- vs. OR=1.08 for EGFR+ tumors, p-heterogeneity=0.001). Stronger inverse associations of absolute non-dense area with breast cancer risk were found for ESR1- as compared to ESR1+ tumors, and for AR+, KRT5/KRT6+, and EGFR+ tumors as compared to respective marker-negative tumors (4th vs. 1st quartile: OR=0.21 for ESR1- vs. OR=0.59 for ESR1+ tumors, p-heterogeneity <0.0001; OR=0.22 for AR+ vs. OR=0.42 for AR- tumors, p-heterogeneity=0.04; OR=0.21 for KRT5/KRT6+ vs. OR=1.14 for KRT5/KRT6- tumors, p-heterogeneity<0.01; OR=0.37 for EGFR+ vs. OR=1.11 for EGFR- tumors, p-heterogeneity<0.01). There were no differences in associations of the density measures with breast cancer by status of other markers evaluated. Conclusions: The findings suggest that some mammographic density measures are differentially associated with the risk of subsequent breast tumor subtypes. Citation Format: Lusine Yaghjyan, Andreas Pettersson, Graham Colditz, Laura Collins, Stuart Schnitt, Andrew Beck, Bernard Rosner, Celine Vachon, Rulla Tamimi. Mammographic breast density and subsequent risk of breast cancer in postmenopausal women according to the status of selected tissue markers: A case-control study. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr PR09.

Abstract Background. The increase in breast cancer risk during pregnancy and postpartum is well known; however, the molecular phenotype of breast cancers occurring shortly after pregnancy has not been well studied. Given this, we investigated whether nulliparity and the time interval since pregnancy among parous women affects the breast cancer phenotype in young women. Materials and Methods. We examined molecular phenotype in relation to time since pregnancy in a prospective cohort of 707 young women (aged ≤40 years) with breast cancer. Parity was ascertained from study questionnaires. Using tumor histologic grade on central review and biomarker expression, cancers were categorized as luminal A- or B-like, HER2 enriched, and triple negative. Results. Overall, 32% were luminal A-like, 41% were luminal B-like, 9% were HER2 enriched, and 18% were triple negative. Although, numerically, patients diagnosed >5 years after pregnancy had more luminal A-like subtypes than women with shorter intervals since pregnancy, there was no evidence of a relationship between these intervals and molecular subtypes once family history of breast cancer and age at diagnosis were considered. Conclusion. Distribution of breast cancer molecular phenotype did not differ significantly among young women by parity or time interval since parturition when important predictors of tumor phenotype such as age and family history were considered. Implications for Practice: Distribution of breast cancer molecular phenotype did not differ among parous young women by time interval since pregnancy. The implication of these findings for clinical practice suggests that pregnancy-associated breast cancers may be seen up to 5 years beyond parturition.