Effect of GSTM1 polymorphism on risks of basal cell carcinoma and squamous cell carcinoma: a meta-analysis

Glutathione S-transferases are important enzymes in the detoxification of a wide range of reactive oxygen species produced during melanin synthesis and oxidative stress processes. Glutathione S-transferase M1 (GSTM1) null genotype may be a candidate genetic polymorphism with a role in susceptibility to skin cancer such as basal and squamous cell carcinomas. We conducted a systematic review and meta-analysis to define the effect of GSTM1 null polymorphism on skin cancer risk. We searched the PubMed, Embase, and Web of Science databases to identify published case–control studies investigating the association between GSTM1 null genotype and skin cancer risk. Between-study heterogeneity was assessed using the I ² statistic. Odds ratios (OR) with corresponding 95 % confidence intervals (95 % CI) from individual studies were pooled using fixed and random effects models. Nineteen case–control studies (4,275 cases and 4,255 controls) were considered eligible and included in the meta-analysis, and 11 of which were on basal cell carcinoma; ten, on melanoma, and seven, on squamous cell carcinoma. Overall, the GSTT1 null genotype was not associated with the risk of skin cancer (OR, 1.01; 95 % CI 0.93–1.11; P?=?0.76). Subgroup analysis by histological types showed that GSTT1 null genotype was not associated with risks of basal cell carcinoma (OR, 1.06; 95 % CI 0.92–1.21; P?=?0.42), squamous cell carcinoma (OR, 0.97; 95 % CI 0.76–1.24; P?=?0.80), and cutaneous malignant melanoma (OR, 1.00; 95 % CI 0.88–1.14; P?=?0.60). Therefore, this meta-analysis suggests that GSTM1 null polymorphism is not associated with risks of basal and squamous cell carcinomas.