Abstract P6-12-06: Preoperative chemotherapy regimens and breast cancer subtype in an underinsured Hispanic population

Abstract

Abstract Background: Although the Hispanic population is among the fastest growing in the United States, however, less is known about them then other populations. Breast cancer in different racial/ethnic populations display different behaviors. The current study was performed to examine response to preoperative chemotherapy regimen and by breast cancer subtype in a Hispanic safety net population. Methods: A retrospective review of Hispanic breast cancer patients who underwent preoperative chemotherapy from July 2001 to February May 2015 at a safety net hospital. Sociodemographic, clinical, and treatment variables were evaluated. Response to chemotherapy regimen was recorded. Breast cancer subtypes were divided based on IHC and FISH testing. Luminal B subtype was classified based on Ki67 (>15%) and PR (<20%). Results: The average age of the 133 patients was 45 years. 93% of the patients were insured with Medicaid or uninsured (70%). The average size of the cancers at presentation was 5cm. Overall 86% of patients had a clinical response to preoperative chemotherapy and 35% had pathologic complete response (pCR). AC and TC regimens had the lowest rate of pCR at 16%. AC/T (every 3 week and weekly) had similar rates of pCR 23% and 29%, while dose dense regimens showed pCR 40%. Herceptin containing regimens had pCR 57%. 7 patients received TAC and 71% had pCR. By subtype, Luminal A and B patients had low rates of pCR 9% and 14% respectively. Luminal B patients did benefit from preoperative chemotherapy as 86% of patients who were not candidates for breast conservation at presentation were able to undergo lumpectomy after preoperative chemotherapy. Her2 subtype patients who got Herceptin had pCR 57%. Triple negative patients had pCR 54%. Conclusions: In this underinsured, Hispanic population who presented at advanced stages, differences in response to preoperative chemotherapy were seen based on breast cancer subtype. Differences were also seen based on chemotherapy regimen. TAC maybe a particularly effective regimen in triple negative Hispanic women. Citation Format: Mehta D, Winton L, Walters J, Hsu C-H, Nodora J, Martinez ME, Bouton M, Komenaka IK. Preoperative chemotherapy regimens and breast cancer subtype in an underinsured Hispanic population. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-12-06.