UC Irvine

IntroductionBreast cancer literature traditionally evaluated the Asian American Pacific Islander (AAPI) population in aggregate, masking its heterogeneity. This study evaluates the pathologic complete response (pCR) of disaggregated AAPI subgroups with triple-negative breast cancer (TNBC) to identify and address disparities within this population.MethodsThe 2018-2020 National Cancer Database identified women with TNBC who received neoadjuvant chemotherapy and surgical excision. pCR was compared amongst White, AAPI, and non-White non-Asian (NWNA) patients.ResultsOf 19,809 women, 71.6% were White, 4.1% were AAPI, and 24.3% were NWNA. Compared to White and NWNA, AAPI patients had the highest pCR (AAPI 43.0% vs White 39.5% vs NWNA 37.1%, P < 0.001). However, disaggregation revealed Koreans to have significantly lower pCR than all subgroups, including both White and NWNA patients, while Japanese and South Asians had the highest pCR of all subgroups. Notably, Koreans and Japanese patients had similar presentations of advanced disease, favorable demographics, and relatively short intervals to chemotherapy but demonstrated pCR rates on opposite extremes.ConclusionWhile AAPI patients with TNBC had a higher pCR than White and NWNA patients, disaggregation of AAPI subgroups reveals poorer pCR for specific subgroups than that of White and NWNA patients. While socioeconomic characteristics may partially explain these differences, the contrasting rates of pCR between Koreans and South Asians despite presenting with similar rates of advanced disease, demographics, and treatment characteristics highlight the contribution of tumor biology to treatment response and the importance of disaggregated data and targeted interventions to address disparities among unique ethnic subpopulations.