COMT 158G/A and CYP1B1 432C/G polymorphisms increase the risk of endometriosis and adenomyosis: a meta-analysis

OBJECTIVE: Catechol-O-methyltransferase (COMT) 158G/A and cytochrome P450-1B1 (CYP1B1) 432C/G gene polymorphisms have been associated with the risk of endometriosis and adenomyosis, but results remain inconclusive. The aim of this study was to investigate the relationships between these polymorphisms and the risk of endometriosis and adenomyosis by meta-analysis. STUDY DESIGN: A search was performed using PubMed, Embase, the Chinese Journals Full-text Database and Wanfang databases up to September 2013. Odds ratios (OR) and 95% confidence intervals (95% CI) were used to evaluate the relationships. Statistical analyses were undertaken using STATA Version 11.0. RESULTS: The literature search identified 10 articles, involving 1770 cases and 2057 controls. The two polymorphisms were found to be significantly associated with the risk of endometriosis and adenomyosis (COMT 158 G/A: AA+AG vs GG: OR 1.20, 95% CI 1.01-1.43; CYP1B1 432 C/G: GG+GC vs CC: OR 1.28, 95% CI 1.01-1.68). In the subgroup analysis by ethnicity, the two polymorphisms were significantly associated with the risk of endometriosis and adenomyosis among Asian populations but not among Caucasian populations. CONCLUSIONS: COMT 158G/A and CYP1B1 432C/G polymorphisms may contribute to the risk of endometriosis and adenomyosis, particularly in Asian populations. Larger studies are required to evaluate this association further.