Background: CYP1A1 is an enzyme in phase I of the cytochrome P450 (CYP) superfamily, and plays a key role in detoxification of carcinogens. Host genetic predisposition in the CYP1A1 may be associated with an increased susceptibility to cervical cancer.The study aimed to evaluate four common polymorphisms of the CYP1A1 and cervical cancer susceptibility among Northeast Thai women. Methods: A case-control study was conducted involving 204 patients with squamous cell cervical cancer (SCCA) and 204 age-matched healthy controls. DNA was extracted from peripheral blood leucocytes. CYP1A1 m1, m3, and m4 genotypes were detected using PCR-RFLP, whereas the CYP1A1 m2 genotype was investigated using real-time PCR. Haplotype analysis was performed using PHASE algorithm version 2.1.1. Results: CYP1A1 m3 was monomorphic. Association between the common CYP1A1 polymorphisms, m1 and m2, and cervical cancer risk was not observed (p>0.05), nor was any association found between the m1-m2-m4 haplotype and cervical cancer risk (p>0.05). Interestingly, the CA genotype of CYP1A1 m4 was observed in 30.88% of the cervical cancer patients but was absent in healthy controls. Conclusion: Our results demonstrated a possible involvement of the CYP1A1 m4 polymorphism but no other common polymorphisms (viz., m1, m2, and m3) in the risk for cervical cancer.This finding may be useful when screening for risk of cervical cancer among Northeast Thai women.

Background: Exposure to certain carcinogens together with host genetic predisposition likely has an influence on cervical carcinogenesis. Objective: Our aim was to evaluate synergistic effects of glutathione S-transferase (GST) polymorphisms and risk behaviors (i.e., smoking and contraceptive use) on squamous cell cervical cancer (SCCA) development in northeastern Thailand. Methods: Subjects were 198 (SCCA) patients and 198 age-matched healthy controls. Multiplex PCR and PCR-RFLP were used to determine GSTT1 and GSTA1 gene polymorphism, respectively. Results: Interaction between the four polymorphic loci of GSTs (GSTM1, GSTT1, GSTP1 and GSTA1) and increased risk for cervical cancer was not observed. The three genotypes of GSTM1 consistently showed significant risks of smoking with a lower OR for the Null individuals (1.741) at around one -fourth of wild type homozygous individuals (8.000). The effects of GST polymorphisms on cervical cancer risk under the use of hormonal contraceptives apparently did not occur. Conclusions: The predisposition of smoking risk is related to the GST genotype. It is suggested that knowing one’s own genotype data will contribute to the prevention of SCCA by controlling risk habits.