Lack of participation of the GSTM1 polymorphism in cervical cancer development in Northeast Thailand

Polymorphic variants conferring genetic risk to cervical lesions support GSTs as important associated loci

To analyze the association between glutathione S-transferases polymorphisms and the risk of cervical lesions.Case-control studies focusing on the association between glutathione S-transferase polymorphisms and the risk of cervical lesions were collected from the PubMed, Web of Science, Cochrane Library, Embase, Medline, CNKI, VIP and Wanfang databases from inception to August 2018. Pooled odds ratios and 95% confidence intervals were employed to evaluate the strength of the association. Subgroup analysis and sensitivity analysis were used to test the potential discrepancy and robustness, respectively.A total of 30 studies comprising 3961 patients and 4726 healthy controls satisfied the inclusion criteria. Of these, 6 studies contained information about GSTP1, 27 studies contained information about GSTM1, and 22 studies contained information about GSTT1. Our results supported that there was no statistical association between GSTP1 polymorphism and the risk of cervical lesions (odds ratio [OR] = 1.08, P = .40). The GSTM1 null variant showed increased susceptibility to cervical lesions (OR = 1.45, P < .001). Subgroup analysis revealed that the GSTM1 null variant caused cervical lesions among HPV infection cases (OR = 1.69, P = .02) and among the Chinese and Indian populations (OR = 2.24 and OR = 1.87, respectively, P < .001). The GSTT1 null variant increased the risk of cervical lesions in smokers (OR = 1.52, P = .03). The GSTT1 null genotype was also related to high-grade intraepithelial neoplasia (HSIL) and cervical cancer risk (OR = 1.30 and OR = 1.78, respectively, P < .05).The GSTM1 null variant caused cervical lesions, especially among HPV infection cases and among the Chinese and Indian populations. The GSTT1 null variant increased the risk of cervical lesions in smokers and was also related to HISL and cervical cancer risk.

Preliminary Study of the GSTM1 Null Polymorphism and History of Tobacco Smoking among Oral Cancer Patients in Northeastern Thailand

Risks with GSTM1 genotypes and potential roles of smoking in the susceptibility to oral squamous cell carcinoma (OSCC) were studied in Northeastern Thailand. Study subjects were 79 histologically-confirmed OSCC cases (31 men, 48 women) and 79 age- and sex-matched healthy controls ranging in age from 25 to 84 years. GSTM1 genotyping was achieved by two independent PCR assays. The GSTM1 null allele and the homozygous genotype did not increase risk of OSCC vs the wild type allele and the remaining genotypes. When the focus was on the smoking habit, male subjects who smoked ≥10 or ≥35 years were at significantly increased risk for OSCC with adjusted ORs of 4.88 [95%CI, 1.41-16.87, p=0.012] or 4.94 [95%CI, 1.62-15.12, p=0.005], respectively. A higher risk for OSCC was found for smoking amount; those who smoked >5 or >10 pack-years were at a higher risk with adjusted OR of 4.46 [95%CI; 1.45-13.74, p=0.009] or 3.89 [95%CI; 1.34-11.28, p=0.012], respectively. There are certain smoking patterns that give greater risks and thus both smoking duration and pack-years should be taken into consideration in tobacco related cancer prevention.