Glutathione S-transferase (GST) enzymes catalyse the detoxification of by-products of reactive oxygen species and are thus important in cellular defence mechanisms. The GSTs are polymorphic with allelic variants encoding isoforms with functional differences. GST polymorphism has been associated with susceptibility and clinical outcome in patients with cancer. In this retrospective cohort, we have investigated associations between common GSTM1, GSTM3 and GSTP1 polymorphisms with factors known to influence clinical outcome and patient survival in colorectal cancer. Significant linkage disequilibrium was demonstrated between GSTM1 and GSTM3 alleles (P≤0.001). We identified no significant associations between the GSTP1 Ile105Val105 polymorphism and any clinical outcome parameters or patient survival. However significant associations were demonstrated with mu class GSTs. Those patients who were GSTM1 null presented less frequently with poorly-differentiated tumours (P=0.038). Furthermore, patients who were GSTM3 AA were less likely to present with advanced stage tumours (T-stage, P=0.036 and Dukes' classifications, P=0.012) or distant metastases (P=0.017) when examined alone. Upon further examination of the effect of linkage disequilibrium, we found that, in GSTM1 null individuals, GSTM3 AA (compared with other GSTM3 genotypes combined) had longer disease-free survival (HR=0.54, 95% CI 0.30-0.98, P=0.044). Thus, the GSTM3 AA genotype is associated with improved prognosis especially in those with GSTM1 null. Our findings suggest that the GST mu gene cluster mediates tumour characteristics and survival in patients with colorectal cancer.
The recent introduction of restorative proctocolectomy for the treatment of ulcerative colitis has reopened the debate about the effects of ileostomy on quality of life. This study analysed life quality and psychological morbidity in 113 patients with an ileostomy using a postal questionnaire which included questions about their opinion of the pouch operation. Of the questionnaires, 73 per cent were suitable for analysis. A total of 93 per cent of those responding were happy with the ileostomy and appeared to have adapted to a normal life with it. Some 87 per cent stated that they would keep the ileostomy in preference to an ileoanal pouch. In addition, psychological morbidity as assessed by the General Health Questionnaire occurred in only 5 per cent of patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.