Treatment patterns and clinical outcomes of patients with early triple negative breast cancer at a tertiary medical center.

Abstract

e12624 Background: The clinical benefit of neoadjuvant chemotherapy in patients with early triple negative breast cancer (eTNBC), especially those with clinical stage I (cStage I) disease, remains unclear. This study aims to examine the treatment pattern and outcomes of patients with eTNBC treated at a tertiary medical center. Methods: After receiving IRB approval, clinical characteristics, treatment patterns and invasive disease-free survival (iDFS) outcomes of patients with eTNBC treated in 2009-2019 were compared between those who received adjuvant chemotherapy (AC) vs. neoadjuvant chemotherapy (NAC). Inverse probability weighting (IPW) statistical methods were used to adjust for subgroup imbalances including age, race, clinical T and N stage. Results: Study cohort (n=919) was 70% white and 25% black. Median follow-up for AC and NAC was 49+/-26 and 28+/-19 months respectively. The majority, 56% (400/717), in AC had cStage I disease while only 8% (16/202) in NAC had cStage I disease. Other clinical characteristics were summarized in Table. The most common chemotherapy regimen used in AC and NAC groups was AC-T: 58% and 79%; followed by TC: 32% and 4%; and carboplatin: 2% and 5% respectively. pCR was noted in 83 patients (41%). Multivariate analyses using IPW showed that AC conferred an improved iDFS with a gain of 18 months in those with <=cStage IIA compared to NAC with pCR (Table). Conclusions: Despite limitations including our small sample size and retrospective study design, our results showed that NAC appeared to only benefit eTNBC patients with higher disease burden (>=cStageIIB). Future work to elucidate the clinical benefits of emerging novel NAC strategies in eTNBC will be of interest. [Table: see text]