Subgroup analysis showed a significant relationship between squamous carcinoma (SC), adenocarcinoma (AC) or small cell lung carcinoma (SCLC) and GSTM1 null genotype, as well as SC or AC and GSTT1 null genotype.
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.
Moreover, a significant increase in the risk to SCC of lung in the cases carrying combination of variant genotype of CYP1A2 with either CYP1A1 or GSTM1 have shown that gene-gene interactions may play an important role in squamous cell lung cancer risk.
The frequency of one null genotype of the GSTM1 or GSTT1 gene was higher in patients with pharyngeal SCC and heavy smoking status than in controls (76.3% versus 57.7%, P = 0.04).
The genotype for GSTM1 (mutation vs. wild type) was determined by polymerase chain reaction (PCR) using genomic DNA extracted from peripheral blood from 28 OSCC patients.
The combined 'at risk' genotypes of GSTM1 null and GSTT1 null in comparison with 'wild-type' genotypes seems to be associated with a greater risk of lung cancer, but the results are not significant (odds ratio (OR) 2.0, 95% confidence interval (CI) 0.68-5.96) and for squamous cell carcinoma (SqCC) it was 1.6-fold (OR 1.6, 95% CI 0.49-5.68).
In this study we were unable to show a correlation between GSTM1 and GSTT1 genotypes and the development of head and neck squamous cell carcinomas in cigarette smokers.
GSTM1 polymorphisms seem to be involved in BCC risk, while GSTM1 null/null genotype combined with CYP1A1 allele Val(462) are associated with a higher risk for SCC, indicating that allelism and/or interactions between allelic variants at other loci may also influence the risk of NMSC, particularly SCC.
The purpose of this study was to evaluate the prognostic ability of polymorphisms of three genes involved in the metabolism of tobacco carcinogens (GSTT1, GSTM1, GSTP1) and one polymorphism of a DNA repair gene (XRCC1) for patients diagnosed with squamous cell carcinoma (SCC).
Accumulation of certain alleles or genotypes of the CYP1A1, NAT2, GSTM1 and XPD seems to be associated with either increased or decreased risk to develop laryngeal SCC.
The GSTM1 null genotype was associated with a decreased risk of squamous cell carcinoma: the OR, adjusted for age, sex and pack years was 0.32 (95% CI 0.12-0.82).
Among AC and SCC cancer patients, individuals with the GSTM1-null genotype had an OR of 1.80 (95% CI, 1.1-2.8; case-only analysis) of having AC versus SCC if they also carried a p53 Pro allele.
While adjusted odds ratios (ORs) indicated no significantly increased risk for lung cancer overall due to any single GST genotype, the risk alleles for GSTM1, GSTM3 and GSTP1 conferring reduced enzyme activity were present at higher frequency in SCC than in AC patients.
Analysis of the interaction between GSTM1 null and sunbathing score showed that the two factors were synergistic and individuals with both risk parameters demonstrated a shorter time from transplantation to development of the first SCC (p = 0.012, hazard ratio = 7.1).
Individuals with a combined genotype of Val/Val and GSTM1(-) were at an increased risk for oral SCC compared with other combined genotypes, in particular, at a low dose level of cigarette smoking.
These results are supported by logistic regressions of patients allowing interactions between tumour type (or treatment) and PY (or age), and indicate that the GSTM1-null genotype could be an important susceptibility factor for SQ while the NAT2-slow genotype may have an impact on other types of lung cancer.
Accordingly, we have examined, in patients with one squamous cell carcinoma (SCC) of the head and neck, associations between GSTM1, GSTT1, GSTM3, GSTP1, CYP2D6, CYP1A1, CYP2E1, and CCND1 genotypes and the outcome parameters, tumor extension, histological grade, and presence of nodes.
Because the most common type of nasopharyngeal cancer (NPC), squamous cell carcinoma, is related to smoking, we sought to determine whether GSTM1 is associated with risk for NPC.