No relationship between ovarian cancer risk and progesterone receptor gene polymorphism in a population-based, case-control study in North Carolina
The protective effects of pregnancy and OC3 use on ovarian cancer risk may be attributable to the action of progestins on the ovarian epithelium (1) . It has been hypothesized that a PROGINS is associated with increased risk of ovarian cancer. The PROGINS polymorphism has functional significance (2) and was associated with ovarian cancer in a pooled German/Irish population (3) . A study of BRCA1 and BRCA2 mutation carriers found that the PROGINS allele was associated with a 2.4-times increased risk of ovarian cancer among the subgroup that had never used OCs (4) . In contrast, no association between PROGINS and sporadic ovarian cancer risk has been identified in several studies with ORs ranging from 0.85 to 0.95 (5 , 6) . In light of these conflicting reports, we sought to investigate the hypothesis that the PROGINS allele is associated with increased ovarian cancer risk.