Glutathione S-transferase null genotypes in transitional cell bladder cancer - A case-control study

Objectives: This study was conducted (1)to examine whether the GSTM1 and GS TT1 null genotypes are risk factors for bladder cancer, and (2) to study a possible association of these genotypes with disease severity. Methods: This case-control study was undertaken over a 21-month period and included 89 newly diagnosed transitional cell bladder cancer patients and 1 47 controls; both patients and controls originated from a defined populatio n (residents of the loannina region, Northwestern Greece) and were similar with regard to mean age, male to female ratio and smoking habits. The GSTM1 and GSTT1 genotypes were identified by multiplex polymerase chain reaction on peripheral blood DNA samples. Genotype frequencies among patients and c ontrols were assessed and the association of the genotypes with tumor grade and stage at presentation were statistically evaluated by the chi(2) test. Results: The GSTM1 null genotype was strongly associated with bladder cance r. The odds ratio, attributable and population attributable risks were esti mated at 2.76, 0.64 and 0.40, respectively. The correlation between the GST M1 null genotype with stage, although not statistically significant, was es timated at an odds ratio of 2.6 for invasive disease. The correlation of GS TM1 null genotype with tumor grade did not yield a statistically significan t result. The GSTT1 null genotype was not statistically associated with bla dder cancer. Conclusion: According to our study, individuals with the GSTM1 null genotyp e carry a substantially higher risk for bladder carcinogenesis. The GSTM1 n ull genotype is not associated with more aggressive disease in terms of tum or grade, although there is a correlation between this genotype and stage o f the disease. Copyright (C) 2000 S. Karger AG, Basel.