Abstract
BACKGROUND: GSTM1 and GSTT1 are phase II enzymes which provide chemical defense to cells. OBJECTIVE: This study was designed to evaluate association of GSTM1 and GSTT1 deletion along with epidemiological factors with risk of colon and rectum cancers. METHODOLOGY: Multiplex PCR was used for cancer patients as well as age and gender matched cancer free controls. RESULTS: 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. CONCLUSION: These results suggest that GSTM1 and GSTT1 deletion were associated with increased risk of colon and rectum cancer in Pakistani population.