Abstract 1940: Outcomes of patients treated with neoadjuvant chemotherapy for breast cancer at a safety net hospital
Authors: Srivastava Prakriti , Blackwell James-Michael , Bullock Jolonda , Basha Riyaz , Narra Kalyani 
Published: April 2023

Background: Neoadjuvant chemotherapy (NAC) is administered before surgery and expected to benefit certain breast cancer (BC) patients (pts). This study inspected outcomes of triple negative BC (TNBC), hormone receptor (HR) positive (+) HER2 negative (-), and HER2+ BC pts treated with NAC at John Peter Smith Hospital (JPS) in Tarrant County, TX.

Methods: It is an IRB exempted retrospective review of JPS Oncology and Infusion Center’s registry data. Eligible pts were diagnosed with TNBC, HR+ HER2-, or HER2+ BC from 1/1/2016 to 12/31/2019 and underwent NAC. Age, race, NAC regimen, tumor grade, recurrence, and pt survival were collected from EPIC EMR. NCCN guidelines were used to standardize clinical prognostic and pathologic anatomic stages. Decrease in stage by at least one level was considered as improvement.

Results: Refer to table for additional results. Total of 104 pts. 22 (21.2%) had recurrence, 14 (14.5%) had died. Using the full cox proportional hazard model, TNBC pts had a 3.214 times higher hazard of death/recurrence compared to other subsets (95% CI: 1.261, 8.193; p= 0.0145). 70 (67.3%) pts showed improvement in stage. 34 (32.7%) achieved pathological complete response (pCR). When compared to pts with residual disease, achieving pCR reduced hazard of death/recurrence by 71.6% (HR: 0.284; 95% CI: 0.095, 0.849; p= 0.0243).

Conclusion: A clear unmet need is poor survival of Black TNBC pts. Safety net hospitals, like JPS, disproportionately treat Black pts. We show that attaining pCR correlates with improved survival, but less than a quarter of TNBC pts attained pCR. New NAC regimens with Pembrolizumab has become standard of care for TNBC pts since 2021 due to higher pCR rates. Still, there is a need for better NAC regimens to improve pCR in TNBC overall and clinical trials on new regimens should include Black pts. Also, more than a third of HR+ HER2- pts upstaged in LN after NAC. This suggests a need for pre-NAC radiology staging methods and better NAC regimen testing for this subset.

TNBC(32 patients) HR+, HER2-(29 patients) HER2+(43 patients) TOTAL(104 patients, 103 women) Median Age Median Age 58 50 53 53 Racial Distribution of Patients Non-Hispanic White 9(28.1%) 11(37.9%) 11(25.6%) 31(29.8%) Black 18(56.3%) 12(41.4%) 15(34.9%) 45(43.3%) Hispanic 4(12.5%) 2(6.9%) 10(23.3%) 16(15.4%) Asian 1(3.1%) 4(13.8%) 7(16.3%) 12(11.5%) Clinical Prognostic Stage Before NAC and Surgery 1 1(3.1%) 0(0%) 9(20.9%) 10(9.6%) 2 8(25%) 13(44.8%) 20(46.5%) 30(28.8%) 3 22(68.8%) 16(55.2%) 14(32.6%) 52(50%) 4 1(3.1%) 0(0%) 0(0%) 1(0.9%) Pathologic Anatomic Stage After NAC and Surgery pCR 7(21.9%) 3(10.3%) 24(55.8%) 34(32.7%) 1 8(25%) 3(10.3%) 14(32.6%) 24(23.1%) 2 9(28.1%) 9(31%) 3(7%) 21(20.2%) 3 8(25%) 14(48.3%) 2(4.7%) 24(23.1%) 4 0(0%) 0(0%) 0(0%) 0(0%) Tumor Stage Difference Before/After Surgery Improvement 24(75%) 11(37.9%) 35(81.4%) 70(67.3%) Deterioration 1(3.1%) 7(24.1%) 0(0%) 8(7.7%) No Change 7(21.9%) 11(37.9%) 8(18.6%) 26(25%) Recurrence Recurrence 10(31.3%) 4(13.8%) 8(18.6%) 22(21.2%) Patients survived as of 9/19/2022 Survival 25(78.1%) 27(93.1%) 38(88.4%) 90(86.5%) Additional Significant Results Completion of NAC regimen 89 (85.6%) total pts Lymph Node (LN) Upstaging for HR+ HER2- 6 (20.7%) pts showed improvement in LN while 11 (37.9%) upstaged in LN pCR in Black TNBC pts Only 16% of Black pts achieved pCR

Citation Format: Prakriti Srivastava, James-Michael Blackwell, Jolonda Bullock, Riyaz Basha, Kalyani Narra. Outcomes of patients treated with neoadjuvant chemotherapy for breast cancer at a safety net hospital [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 1940.