Purpose: Previous evidence implicates CYP1A1 and GSTM1 polymorphisms as risk factors for various cancers. A number of studies have been devoted to the association of CYP1A1 or GSTM1 polymorphism with susceptibility to laryngeal carcinoma, with the results inconsistent and inconclusive. The aim of the present study was to assess the possible associations of laryngeal cancer risk with CYP1A1 genetic variation and GSTM1 null genotype respectively.
Methods: The associated literature was acquired through deliberate searching and selected based on the established inclusion criteria for publications, then the extracted data were further analyzed using systematic meta-analyses.
Results: The results showed that the overall odds ratio (OR) was 1.32 (95% CI = 1.08-1.61) for CYP1A1 Mspl polymorphism. Using subgroup analysis, the pooled ORs were 1.38 (95% CI = 0.98-1.95) in Asians and 1.29 (95% CI = 1.01-1.65) in Caucasians. For CYP1A1 exon7 polymorphism, the overall OR was 1.38 (95% CI = 0.98-1.95). The overall OR was 1.24 (95% CI = 1.03-1.49) for GSTM1 polymorphism and the pooled ORs were 1.36 (95% CI = 0.75-2.48) in Asians, 1.16 (95% CI = 0.94-1.44) in Caucasians and 1.52 (95% CI = 1.05-2.19) in Turkey population.
Conclusions: The data suggest CPY1A1 MspI polymorphism as a risk factor for laryngeal cancer in Caucasians but not in Asians. However, the results suggest a marked correlation of GSTM1 polymorphism with laryngeal cancer risk in Turkey population but not Caucasians and Asians.