Progesterone receptor PROGINS and +331G/A polymorphisms confer susceptibility to ovarian cancer: a meta-analysis based on 17 studies

Progesterone and its receptor, progesterone receptor (PGR), have been widely studied for their roles in the onset and development of ovarian cancer. Although numerous epidemiological studies have focused on the association of PGR PROGINS and +331G/A polymorphisms with ovarian cancer susceptibility, presently, available results remain controversial, in part due to low sample sizes. Thus, a meta-analysis is required to evaluate this association. A literature search of PubMed, Embase, Web of Science, CNKI, and CBM databases was performed to retrieve eligible studies published before August 15, 2013. Summary odds ratios (ORs) with 95 % confidence intervals (CIs) were used to evaluate the strength of this association. All analyses were done using STATA 12.0 software (Stata Corp., College Station, TX, USA). Seventeen case–control studies with a total of 6,365 cases and 9,998 controls were identified. While no statistically significant association between the PROGINS allele and ovarian cancer risk was found in an overall analysis, a stratified analysis revealed that for Caucasians, never-oral contraceptive (OC) users, and serous tumor patients, there were statistically significant ORs for ovarian cancer risk associated with the mutated PROGINS allele. No significant association, however, between the +331G/A polymorphism and ovarian cancer susceptibility was observed in the overall analyses and subgroup analyses based on ethnicity and histological type. This meta-analysis provides evidence that the PROGINS allele occurs more frequently in ovarian cancer patients and especially in non-OC users and serous cancer patients, indicating that PROGINS may be a risk modifier. No significant association between the +331G/A polymorphism and ovarian cancer was found, even in stratified analyses by ethnicity and histological type. More detailed and well-designed studies are still needed to confirm the role of the PROGINS allele in ovarian cancer development.