Background: Estrogen is crucial for development of benign prostate hyperplasia and prostate cancer. Aromatase (CYP19) is a key enzyme for estrogen synthesis in males. The genetic polymorphism of the CYP19 intron 4 [TTTA]n tetranucleotide has been studied in relation to breast cancer susceptibility.
Materials and methods: We examined the association of the tetranucleotide repeat polymorphism of the CYP19 gene with familial prostate cancer risk in a Japanese population by performing a case-control study consisting of 99 familial prostate cancer cases and 116 normal controls.
Results: [TTTA] repeats ranged from 7 to 13 and were designated as A1 to A7 according to the repeat number. We did not observe any A3 allele among cases and controls, nor A7 among cases. Short repeat alleles, A1 and A2, had a tendency to be frequently observed in cases (odds ratio [OR] = 1.43, 95% confidence interval [CI] = 0.96-2.14, p = 0.080). Analysis of polymorphic genotypes showed that short genotypes, i.e., A1A1, A1A2 and A2A2, significantly increased prostate cancer risk in comparison with other longer genotypes (OR = 1.80, 95% CI = 1.04-3.11, p = 0.035). Stratification of cases according to the pathological grade or the clinical stage showed no significant differences among categories.
Conclusions: In the present study, we found that short polymorphic genotypes of [TTTA]n repeats of the CYP19 gene were associated with familial prostate cancer risk.