Cytochrome P450 1A1 (
CYP1A1) polymorphisms are known to play a crucial role in the development and
metastasis of malignant diseases including
esophageal cancer. However, the results of previous studies investigating the association between
CYP1A1 polymorphisms and
esophageal cancer risk have been inconsistent. This meta-analysis of 27 eligible studies, encompassing 4,215
esophageal cancer cases and 6,339 control subjects, pooled the odds ratios (
ORs) with corresponding 95 % confidence intervals (95 % CI) to assess this association. The effects of ethnicity (Caucasian and Asian) and histopathology type (
esophageal squamous cell carcinoma and esophageal
adenocarcinoma) were considered in subgroup analyses. A significant association was observed between the
CYP1A1 Ile/Val gene polymorphism and
esophageal cancer in all of the genetic models (
Ile/Val vs. Ile/Ile, OR = 1.41, 95 % CI = 1.25-1.58;
Val/Val vs. Ile/Ile, OR = 1.94, 95 % CI = 1.34-2.82; Ile/Val + Val/Val vs. Ile/Ile, OR = 1.49, 95 % CI = 1.33-1.66). The subgroup analysis based on ethnicity showed that the association between the
CYP1A1 Ile/Val polymorphism and
esophageal cancer existed in Asian and Caucasian populations. However, no association was observed between the
CYP1A1 MspI polymorphism and
esophageal cancer in either subgroup or in the overall population. These results suggested that the
CYP1A1 Ile/Val polymorphism was associated with an increased risk of
esophageal cancer, whereas the
CYP1A1 MspI polymorphism may not have increased susceptibility to
esophageal cancer. Further studies are required to confirm these findings.