Abstract B72: Does prostate cancer risk vary by race after accounting for lifestyle factors in the Health Professionals Follow-up Study

Introduction : There are considerable differences in prostate cancer rates among white, black and Asian men, yet the underlying reasons for these differences are unknown. Our objectives were to study the association between race/ethnicity and prostate cancer risk, including aggressive cancer, accounting for differences in lifestyle factors and screening in a socioeconomically homogeneous population of US men. Materials and Methods : We conducted a prospective analysis using the Health Professionals Follow-up study (HPFS), a prospective cohort of 46,108 men that began in 1986 with follow-up through 2012. These men were followed-up through biennial questionnaires that collected lifestyle, medical history and demographic data. After 26 years of follow up, 6,072 new cases of prostate cancer were identified. We used Cox proportional hazards models to calculate hazard ratios (HR) and 95% confidence intervals (CI) for the association between race/ethnicity and prostate cancer risk adjusting for potential confounders and PSA screening history. Results : At baseline in 1986, there were 44,795 Caucasian men, 470 black men and 834 Asian men. Black men had a significantly higher risk of overall prostate cancer (HR=1.38, 95% CI= 1.10 to 1.72) while Asian men had a lower risk (HR=0.73, 95% CI=0.58 to 0.92) compared to white men. These associations were independent of PSA testing history and family history. There was a suggestion of an increased risk of lethal and high-Gleason grade disease for both black (Lethal: HR=1.24, 95% CI= 0.68 to 2.28; High-grade: HR=1.12, 95% CI=0.58 to 2.18) and Asian men (Lethal: HR=1.29, 95% CI=0.75 to 2.23; High-grade: HR=1.43, 95% CI=0.86 to 2.37), compared to Caucasian men, despite the lower risk for overall prostate cancer among Asians. The positive associations with lethal cancer were even more striking in the era before PSA screening was common (before 1994). Conclusion : The increased incidence of prostate cancer overall among black men and reduced incidence in Asian men cannot be explained by differences in PSA testing, family history or other lifestyle factors. Citation Format: Nadine M. Hamieh, Sarah Markt, Sam Peisch, Edward Giovannucci, Kathryn Wilson, Lorelei Mucci. Does prostate cancer risk vary by race after accounting for lifestyle factors in the Health Professionals Follow-up Study. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr B72.