Epidemiological factors related to GSTM1 and GSTT1 genes deletion in colon and rectum cancers: A case-control study.

Abstract

GSTM1 and GSTT1 are phase II enzymes which provide chemical defense to cells. This study was designed to evaluate association of GSTM1 and GSTT1 deletion along with epidemiological factors with risk of colon and rectum cancers. Multiplex PCR was used for cancer patients as well as age and gender matched cancer free controls. Mean age of patients and controls was 45.5 (± 14.6) and 43.5 (± 18.08) years respectively. Among epidemiological factors; gender, age ≥ 50 years, active/passive smoking, naswar addiction, residential area, family history, red meat, fruit and vegetable intake showed no association with CRC (P ≥ 0.05). Symptoms of CRC like altered bowel habits (70%) was more common compared with other symptoms. GSTM1 (P ≤ 0.05) and GSTT1 (P ≤ 0.05) deletions were found to be significantly associated with CRC compared with controls. Association of epidemiological factors like gender, active/passive smoking, naswar addiction, residential area and family history were associated neither with GSTM1 deletion nor to GSTT1 deletion in both cancers (P ≥ 0.05). Significant association was present between stage III and GSTM1 (CI 95% 0.15-1.39) as well as GSTT1 (CI 95% 0.14-2.44) deletion in CRC. These results suggest that GSTM1 and GSTT1 deletion were associated with increased risk of colon and rectum cancer in Pakistani population.