ESTUDO DE POLIMORFISMOS NOS GENES GSTT1 E GSTM1 E SUAS ASSOCIAÇÕES AO TABAGISMO E AO CÂNCER DE CAVIDADE ORAL.

Abstract

The oral cancer is considered a public health problem worldwide. Are estimated for the biennium 2016-2017, in Brazil, 15,490 new cases of this disease that is the result of interactions between genetic and environmental factors, therefore, considered to be multifactorial. Genes related to the carcinogen detoxification process can influence the risk of developing cancer of the oral cavity. The objective of this study was to evaluate the relationship between tobacco risk factor, polymorphisms of GSTM1 and GSTT1 and the risk for oral cancer. The series consisted of 100 cases of patients diagnosed with oral cavity cancer, in 2005 and 2006, in the Hospital Araújo Jorge, Goiânia - GO and 70 control individuals without cancer. After DNA extraction from paraffin material from the group of cases and peripheral blood for the control group, the samples were analyzed by PCR and separated by electrophoresis. The frequency of null polymorphisms for the case group was 28.0% for GSTM1 and 49.0% to GSTT1. Among the control group, the frequency of null polymorphism was 31.5% for GSTM1 and 44.3% to GSTT1. The results showed that the GSTM1 and GSTT1 null genotypes were not associated with oral cancer in the population studied, as well as no significant association of polymorphisms with smoking status has not been established. The overall survival of patients with oral cavity cancer included in this study was 51,71%, however, the prognosis of this disease were not significantly associated with the GSTT1 and GSTM1 polymorphisms. The oral cancer was more correlated whith risk factors than genetic factors. Further studies correlating other xenobiotics metabolizing genes, must be performed in order to elucidate the influence of genetic polymorphisms in increasing the risk for cancer of the oral cavity and other cancers induced by toxic agents.