Cytochrome P450 1A1 gene polymorphisms and cervical cancer risk: A systematic review and meta-analysis

OBJECTIVE: This meta-analysis aims to examine whether the MspI and Ile462Val polymorphisms of cytochrome P450 1A1 (CYP1A1) are associated with cervical cancer risk. METHODS: Eligible case–control studies were identified dated until July 2017. Pooled odds ratios (ORs) were used to assess the strength of the association between the two variants and cervical cancer risk. RESULTS: Thirteen studies were eligible (2148 cases and 2252 controls) concerning MspI polymorphism and 8 studies were eligible (1466 cases and 1690 controls) for Ile462Val polymorphism. MspI polymorphism seemed to result in cervical cancer risk in any genetic model (C allele vs T allele: OR = 1.44, 95% confidence interval [CI] = 1.16–1.79; heterozygous model: OR = 1.40, 95% CI = 1.08–1.82; homozygous model: OR = 2.22, 95% CI = 1.48–3.33, dominant model: OR = 1.50, 95% CI = 1.14–1.98 and recessive model: OR = 1.80, 95% CI = 1.35–2.41); similar significantly increased risk was found among Caucasians and Asians. Ile462Val polymorphism was associated with elevated cervical cancer risk (Val allele vs Ile allele: OR = 1.85, 95% CI = 1.27–2.67; heterozygous model: OR = 1.42, 95% CI = 1.28–1.61; homozygous model: OR = 2.94, 95% CI = 1.15–7.54; dominant model: OR = 2.00, 95% CI = 1.33–3.00); this finding was replicated upon Caucasian population. CONCLUSION: This meta-analysis demonstrated that polymorphisms in MspI and Ile462Val of CYP1A1 were risk factors for developing cervical cancer.