Risk of endometrial cancer and estrogen replacement therapy history by CYP17 genotype

Common variants among genes coding for enzymes in sex steroid biosynthetic pathways may influence the risk of endometrial cancer. We examined the asso ciation between endometrial cancer risk and estrogen replacement therapy (E RT) by CYP17 genotype using 51 incident cases and 391 randomly selected con trols from a multiethnic cohort in Hawaii and Los Angeles, California. The relative risk of endometrial cancer was calculated for ever use versus neve r use of ERT by CYP17 genotype (TT, TC, and CC). We found that women who re ported ever taking ERT were more than twice as likely to develop endometria l cancer as women who never took ERT [odds ratio (OR), 2.24; 95% confidence interval (CI), 1.19-4.23]. Among these women, the risk of endometrial canc er was higher for women homozygous for the CYP17 T allele (OR, 4.10; 95% CI , 1.64-10.3), but not for women with the C allele (OR, 1.31; 95% CI, 0.53-3 .21). These preliminary findings suggest that CYP17 or other variants in es trogen biosynthesis or metabolism pathways may be potential markers of endo metrial cancer susceptibility due to ERT.