Epidemiologic and survival characteristics of breast cancer (BC) among the U.S. Asian Indian and Pakistani women compared with other U.S. population groups: A SEER database study.

Abstract

19 Background: The Asian Indian/Pakistani population living in the U.S. (USAIP) is a rapidly growing minority group with persistent cancer disparities. According to SEER (Surveillance, Epidemiology, and End-Result) database, BC is the most frequently diagnosed cancer in USAIP women.The customizing therapeutic and preventive approaches are important to improve health quality across different population therefore, we conducted the largest epidemiological and survival disparities of BC in USAIP women. Methods: SEER has been collecting and reporting data on USAIP as a separate ethnic group since 1988. Using 18 SEER registries from 1988-2009 and SEER*Stat 7.0.9, we performed frequency and survival sessions (Kaplan-Meier adjusted for age) on USAIP women with BC and compared with non-Hispanic White (NHW), Hispanics (H),and African American women (AA) with BC. Cox proportional hazards regression analysis was performed to estimate relative risks (RR) on BC mortality after adjusting confounders using SAS v 9.3. Results: A total of 2,750 BC cases reported in USAIP women in SEER database, accounting (38%) of all cancers compare to NHW (30%), H (31%) and AA (32%). The median age at diagnosis in USAIP is significantly less (54 y, p < 0.001) than other ethnicities. Significantly more USAIP (14%, p < 0.001) were diagnosed at age < 40y vs NHW (5%), H (7%) and AA(10%). Compare to NHW, USAIP were more likely to have stages III or IV (22% vs. 18%, p < 0.01); ER/PR+ (84% vs. 75%, p < 0.001); poorly differentiated histology (47% vs. 35%, p < 0.001). 5 yr overall survival is better in USAIP (97%, p <0.01) vs NHW (87%), H (83%) and AA (75%). RR of death from BC in US AIP was higher with age (> 71y), stage III or IV, high grades, ER/PR negative, divorced/widowed, and diagnosis year (1988-1994). Conclusions:This study identifies unique biological features and disparities of BC in US AIP women compared with other US populations. The difference in survival is intriguing, and could be due to differences in tumor biology, access to care, and other epigenetic factors.This study has potential implications for screening and therapeutic recommendations for BC in the US AIP population.