Objective: To investigate the association between susceptibility of esophageal squamous cell carcinoma and the genetic polymorphisms of CYP1A1 and GSTM1.
Methods: Subjects were comprised of 107 esophageal cancer patients and 111 healthy controls. Genotyping of both CYP1A1 and GSTM1 were performed in cancer tissues of all 107 patients and peripheral blood leukocytes taken from the controls by polymerase chain reaction.
Results: There were no significant differences in the frequency distribution of CYP1A1 polymorphisms between esophageal cancer patients and healthy controls although the frequency of CYP1A1 with at least one allele of Val showed slightly higher in individuals with esophageal cancer. However, significant difference was observed in the frequency of GSTM1-nulled individuals with esophageal cancer comparing with the controls (P < 0.05). When subjects were categorized by both CYP1A1 genotype and GSTM1 genotype, GSTM1 (-) became markedly expressed in patients with CYP1A1 (I/I) than in the corresponding controls (67% versus 40%, P < 0.01). The frequency of CYP1A1 genotype with at least one allele of Val (I/V and V/V) was also statistically higher in patients with GSTM1 (+), comparing to the corresponding controls (64% versus 41%, P < 0.05).
Conclusions: It was suggested that: genetic polymorphisms of CYP1A1 and GSTM1 were susceptible to esophageal cancer; individuals who are GSTM1-null have an increased risk of developing esophageal cancer; individuals with combined CYP1A1 (I/I) and GSTM1 (-) or with combined CYP1A1 (I/V, V/V) and GSTM1 (+) were more susceptible, when comparing to those with combined CYP1A1 (I/I) and GSTM1 (+).