Abstract 7347: Disparities in breast cancer outcomes among South Asian women: A comparative analysis with White patients
Authors: Jasmin Hundal, Yanwen Chen, Abhay Singh
Journal: Cancer Research (2025)

Abstract Background: South Asians (SA) are among the fastest-growing racial and ethnic immigrant populations in the United States. Despite this, limited research exists on their breast cancer (BC) outcomes compared to other populations. This study examines disparities between SA and White breast cancer patients. Methods: Data from female BC patients aged 18 years or older, diagnosed between 2004 and 2021 were obtained from National Cancer Database. For “RACE”, code “15”, “16”, “17” [“Asian Indian or Pakistani, NOS (formerly code 09)”, “Asian Indian”, “Pakistani”] were considered as the “South Asian”; the code “01” as “White”. Cox proportional hazards models were used to estimate the effect of race/ethnicity on OS unadjusted, or adjusted for age group, insurance status, Charlson-Deyo comorbidity score, socioeconomic indicators (percent without a high school degree, and median income quartiles), facility type, urban or rural residence, treatment types (chemotherapy, radiation, surgery, hormone therapy), and year of diagnosis. All analyses were done via SAS/STAT 15.3, or R 4.2.2. Results: SA were significantly younger at diagnosis, with 37.5% under the age of 50 compared to 21.5% of White (p-value&amp;lt;0.001). A larger proportion of SA were privately insured (62.9%) compared to White (53.7%), with fewer relying on Medicare (17.3% vs. 36.9%) (p-value&amp;lt;0.001). SA were also more likely to reside in areas with higher median income and education levels. Regarding clinical presentation, SA had higher advanced-stage diagnoses (12.8% Stage III-IV) compared to White (11.6%) (p-value&amp;lt;0.001). Tumor subtype distributions revealed that 45% of South Asians had HR+/HER2- cancers compared to 43.3% of Whites, and the prevalence of Triple-Negative breast cancer was slightly higher in SA (7.9%) than in White (6.0%) (p-value&amp;lt;0.001). Treatment patterns showed nearly identical rates of 63.1% SA and 63.2% of Whites received hormone therapy (p-value=0.741), with slightly different surgery rates (93.0% vs. 93.7%) (p-value&amp;lt;0.001). However, SA was less likely to receive chemotherapy (24.7% vs. 17.4%) (p-value&amp;lt;0.001) but had comparable radiation therapy rates (57.1% vs. 57.8%) (p-value=0.055). Survival analyses indicated better outcomes for SA in HR+/HER2- cancers across all stages (e.g., Stage I: HR 0.560, p&amp;lt;0.001) and in HR-/HER2+ cancers at advanced stages (e.g., Stage IV: HR 0.528, p=0.002). Mortality greater than 90 days after surgery was lower for South Asians (81.9%) compared to White (86.1%) (p-value&amp;lt;0.001). Conclusion: SA exhibit several distinctive characteristics compared to White BC patients, including a younger age at diagnosis, higher socioeconomic status, and better survival outcomes. These findings underscore potential differences in tumor biology, healthcare access, and treatment patterns. Future research should explore systemic, genetic, and social determinants underlying these distinctions. Citation Format: Jasmin Hundal, Yanwen Chen, Abhay Singh. Disparities in breast cancer outcomes among South Asian women: A comparative analysis with White patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 7347.