Abstract LB-392: Ethnic/racial differences in bladder cancer risk: the Multiethnic Cohort

Abstract

Abstract Few studies have examined differences in bladder cancer risk among ethnic groups in the United States. We investigated racial/ethnic differences in bladder cancer risk and cancer stage and risk factors for bladder cancer among 189,998 African-American, Japanese-American, Latino, Native Hawaiian, and White men and women in the Multiethnic Cohort Study. We included 880 incident cases of bladder cancer (685 males and 195 females) identified in the cohort over an 11-year period, between baseline (1993 through 1996) and 2004. Data on known/potential risk factors for bladder cancer were obtained from the baseline questionnaire. Among many potential risk factors examined, only cigarette smoking-related variables (e.g. cigarette dose, years of smoking, pack-years, and years since quitting) were significantly associated with risk of bladder cancer in both men and women; the associations were observed in all five racial/ethnic groups. Racial/ethnic differences in bladder cancer risk were observed in men (P<0.0001) and women (P=0.001). Whites, by far, had the highest risk of bladder cancer compared to other racial/ethnic groups; the relative risks (RRs) (vs. Whites) were 0.65 [95% confidence intervals (CI): 0.53, 0.80] for African Americans, 0.63 (95%CI: 0.46, 0.86) for Native Hawaiians, 0.59 (95%CI: 0.49, 0.69) for Japanese, and 0.41 (95%CI: 0.33, 0.50) for Latinos. After adjustment for cigarette dose, the RRs were 0.69 (95%CI: 0.56, 0.85) for African Americans, 0.65 (95%CI: 0.47, 0.89) for Native Hawaiians, 0.62 (95%CI: 0.52, 0.73) for Japanese, and 0.48 (95%CI: 0.38, 0.59) for Latinos. Similar results were obtained when other smoking variables were considered for adjustment. Although Whites had the highest risk of developing bladder cancer, African-American (P=0.007) and Latino (P=0.008) women were more likely to be diagnosed with advanced disease. Among current and former cigarette smokers, regardless of their smoking dose, Whites were more susceptible to bladder cancer than African Americans, Hawaiians, Japanese, and Latinos. Results from this study suggest that differences in self-reported smoking characteristics among men and women of different races/ethnicities do not fully explain interethnic differences in bladder cancer risk. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-392.