Background: the present study evaluates genetic polymorphisms of three glutathione S-transferases (GSTM1, GSTT1and GSTP1) in patients with synchronous malignant colorectal tumors and the association of synchronous colorectal cancers with other cancers.
Material and methods: from 420 patients with a colorectal cancer admitted to our hospital between 2005-2012, we selected for genetic analysis 20 patients with multiple synchronous malignant colorectal tumors and 9 patients with asynchronous association of colorectal cancer with another cancer. We searched for GST genotypes, comparing the results with controls.
Results: the genetic analysis was possible only in 19 patients with colorectal synchronous cancers and 9 patients with asynchronous association of colorectal cancer with another cancer; we found a statistically significant difference for null GSTM1 genotype frequency between these patients and the control group; we found no differences regarding the frequency of null GSTT1 genotype and Ile105Val polymorphism of GSTP1 in patients with synchronous cancers compared with the control group.
Conclusion: in our study we found the null GSTM1 genotype as a risk factor for multiple colorectal synchronous cancers and for an association of synchronous colorectal with other cancers