COMT and prostate carcinoma: By contrast, the homozygous AA genotype of rs4680 (COMT) appeared to be inversely associated with prostate cancer risk in adjusted models, for both Afro-Caribbean (OR: 0.53; 95% CI: 0.32–0.88; Ptrend: 0.04) and native African (OR: 0.26, 95% CI: 0.08–0.83; Ptrend: 0.003) populations.