The significance of biological, environmental, and social risk factors for prostate cancer in a cohort study in Brazil.
To evaluate the significance of several risk factors for prostate cancer in a cohort of Brazilian men. Men ≥ 40 years-old participating in a prostate cancer screening program between December 2006 and April 2011 in the city of Curitiba, Brazil, were evaluated to determine the prevalence, relative risk (RR) and 95 % CI of prostate cancer according to age, race, ethnicity, family history of prostate cancer, educational level, and history of vasectomy, increased blood pressure, diabetes mellitus, and urethritis. In 2121 men included in this study, prostate cancer prevalence was 0.6 % for men between 40-49 years versus 2.0 % (adjusted RR = 2.58), 7.7 % (adjusted RR = 5.76), and 8.4 % (adjusted RR = 4.88) for men 50-59 years, 60-69 years, and ≥ 70 years, respectively (p < 0.05 to all). The prevalence of cancer was 5.1% in blacks versus 3.3 % in whites (adjusted RR = 1.56, p > 0.05); 6.1 % in African descendants, in comparison to 3.0 % in non-African descendants (adjusted RR = 3.17, p < 0.05); 5.1% in men with a positive family history, compared to 2.5 % in those with no family history (adjusted RR = 1.55, p > 0.05); and 4.8 % in participants with incomplete elementary school level or lower, compared to 2.2 % in men with complete elementary school level or higher education (adjusted RR = 1.85, p > 0.05). Men with/without history of vasectomy, increased blood pressure, diabetes, and urethritis had a prostate cancer prevalence of 0.8 %/3.0 % (adjusted RR = 0.23, p > 0.05), 3.8 %/2.2 % (adjusted RR = 1.16, p > 0.05), 3.7 %/2.6 % (adjusted RR = 1.39, p > 0.05), and 2.6 %/2.6 % (adjusted RR = 0.99, p > 0.05), respectively. Risk factors associated with an increased prevalence of prostate cancer in this cohort included increasing age and African ethnicity.