CYP17 promotor polymorphism and ovarian cancer risk

The CYP17 gene encodes the cytochrome P450c17 alpha enzyme, which functions at 2 different points in the steroid biosynthesis pathway, and is consider ed a candidate susceptibility gene for endocrine-related tumors. A T to C s ubstitution polymorphism exists in the 5' promoter region of this gene, and creates an additional Sp I-type motif. Several studies have examined this polymorphism as a risk factor for breast cancer, but results have been conf licting. We examined 319 cases of ovarian cancer and 298 unaffected control s for the T-C polymorphism, There was no significant difference between cas es and controls for the allele frequencies (p = 0.6), or for genotype distr ibution (p = 0.9). The odds ratio (95% confidence interval) for ovarian can cer was 1.13 (0.70-1.82) for the putative "cancer susceptibility" CC genoty pe and 1.07 (0.77-1.48) for any C allele (CC or CT genotype), Results were little different after adjustment for age. Stratification of the ovarian ca ncer cases according to form (benign, low malignant potential or invasive), histology, grade or stage failed to reveal any heterogeneity with respect to CYP17 genotype. Our data provide no evidence for an association between ovarian cancer risk and the genotype defined by the CYP175' promoter region T-C polymorphism, (C) 2000 Wiley-Liss, Inc.