Abstract P3-13-03: Association between Ethnicity and Survival after Breast Cancer in a Multi-Ethnic Asian Setting: Results from the Singapore-Malaysia Hospital-Based Breast Cancer Registry

Background: Little is known on the impact of ethnicity on survival after breast cancer in the multi-ethnic Asian setting. Material and Methods: Using the multi-institutional Singapore-Malaysia hospital-based breast cancer registry, we investigated the association between ethnicity and risk of mortality after breast cancer in 3,366 patients diagnosed between 1990 and 2007 (Chinese: 77%, Malay: 15%, Indian: 8%). Kaplan-Meier analysis was used to estimate overall cumulative survival (OS). Multivariable hazard ratios (HR) adjusted for tumor and treatment characteristics were computed using Cox regression analysis after splitting follow-up time along the age-axis and calendar-time axis. Results: Malay patients presented at younger age compared to Chinese and Indians (47years vs 52years vs 53years, respectively, P After adjustment for tumor and treatment characteristics, Malay patients had approximately 60% higher risk of death than the Chinese (HR:1.57; 95%CI:1.40-1.77). Indian ethnicity was not significantly associated with risk of mortality after breast cancer compared to Chinese (HR:1.12; 95%CI: 0.98-1.30). Conclusion: In the Asian setting, Malay ethnicity seems to be associated with significantly poorer survival after breast cancer, independent of tumor and treatment profile. The underlying reasons for this association are unclear but may be explained by variations in susceptibility to treatment, co-morbidity and lifestyle after diagnosis of breast cancer. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-13-03.