Polymorphism of GSTM1 gene in patients with colorectal cancer and colonic polyps

The frequency of the GSTM1 gene in patients with nonpolyposis colorectal ca ncer (CRC) (n = 70) and in subjects with colonic polyps (n = 27) was evalua ted and compared with healthy individuals (n = 145). Patients with CRC were divided into the three groups: patients coming from the families with hereditary nonpolyposis colorectal cancer (HNPCC) (n = 17 ); patients with a high risk of HNPCC who were referred to as suspected of HNPCC (n = 25); patients with sporadic colorectal cancer without clinical f eatures of hereditary tumours (n = 28). A simple polymerase chain reaction (PCR) - based assay to identify GSTM1 nu lled and positive (non-nulled) genotype was used. No significant differences in frequency of nulled individuals were observed in both patients with HNPCC and patients suspected of HNPCC as well as in subjects with colonic polyps. The most interesting observation was made in the group of patients with sporadic CRC. Twenty individuals (71.4 %) of the group were GSTM1 deficient which was significantly different from the cont rol population (p < 0.04). The above data indicate that the absence of the GSTM1 gene is associated with a greater risk of sporadic colorectal cancer. There is an increase in the overall risk of similar to 2.5. as compared wi th the control population.