The frequency of GSTT1 null genotype in Turkish population and lung cancer risk

BACKGROUND: Previous studies have suggested that Glutathione S-transferase (GST) genotypes may play a role in determining susceptibility to lung cancer, though the data are often conflicting. In different ethnic groups variations in null allele frequency has been observed. AIMS: We aimed to evaluate whether genetic polymorphisms of Glutathione S-transferase theta (GSTT1) influence individual susceptibility to lung cancer in Turkish population. We tried to clarify the frequencies of GSTM1 gene polymorphisms in a Turkish population. METHODS: DNA samples, extracted from the whole blood were amplified using polymerase chain reaction (PCR) method in all of the 68 cases, composed of 31 previously diagnosed lung cancer and 37 healthy controls. RESULTS: The prevalence of GSTT1 null genotype in the lung cancer patients was 29%, compared to 11% in control group. GSTT1 null genotype was found to be higher in cancer group compared to the control group, although it was not statistically significant (OR = 3.37, 95% CI = 0.92– 12.32, P = 0.06). There was also no significant relation in GSTT1 genotypes among histopathology types of lung cancers. The frequency of GSTT1 was found to be 25.4% (n = 952) when the studies of Turkish population were reviewed. CONCLUSION: It can be concluded that carrying the GSTT1 null genotype may be accepted as a weak risk factor for the susceptibility to lung cancer.