Prostate cancer risk is three-fold higher among men, aged 50-64, of African descent compared with men of Asian-Indian descent in Trinidad and Tobago

Abstract

Objective: To test the hypothesis that the screening-detected prevalence of prostate cancer is higher among men of African descent than among men of Asian-Indian descent living in Trinidad & Tobago.

Design: Population-based prostate cancer screening study among men aged 50-64.

Setting: Caribbean islands of Trinidad and Tobago.

Participants: Tobago, population-based sample of 1196 male residents of African descent; Trinidad, 173 agricultural workers of Asian-Indian descent.

Interventions: Serum prostate specific antigen (PSA, Abbot AxSYM) and digital rectal exam (DRE) were used to screen men for prostate cancer. Men with elevated PSA (> or = 4 ng/mL) and/or abnormal DRE were offered an ultrasound guided sextant biopsy of the prostate gland.

Main outcome measures: Prevalence of abnormal screen; prevalence of prostate cancer.

Results: Elevated PSA and/or abnormal DRE were observed in 29% (348/1196) of Afro-Tobagonian men. Three hundred sixteen men underwent biopsies. Screening-detected prostate cancer prevalence was: 4.9% (23/468) for those aged 50-55; 7.7% (28/366) for those aged 55-59; and 13.3% (48/362) for those aged 60-64 years. Screening was abnormal in 18% (31/173) of Asian-Indian men; 25 underwent biopsies. Prostate cancer prevalence in Asian Indian men was: 1.6% (1/63) for those aged 50-54; 1.4% (1/71) for those aged 55-59; and 5.1% (2/39) for those aged 60-64 years. Mantel-Haenszel age-adjusted rate ratio was 3.4, 95% CI 1.3-9.0.

Conclusions: This study establishes a high prevalence of screening-detected prostate cancer among Afro-Tobagonians compared with Indo-Trinidadians. Comparison of candidate genes, environmental, and lifestyle factors between these populations may identify factors that increase risk for, or provide protection against, prostate cancer.