50. Clinicopathological correlates and prognostic significance of glutathione S-transferase PI (GSTP) expression in 469 patients after potentially curative resection of node-positive colonic cancer

Background and aim Increased expression of glutathione S-transferase pi (GSTP) has been shown to be associated with poor prognosis and reduced survival in many cancers. Our study aimed to examine the association between GSTP expression, histopathology and survival in a large consecutive series of patients after potentially curative resection for node-positive stage C colonic adenocarcinoma. Methods and results Nuclear and cytoplasmic GSTP expression in both superficial and deep parts of the tumour were assessed retrospectively by tissue microarray and immunohistochemistry in specimens from 469 patients, whose other histopathology had been recorded in a prospective hospital registry of large bowel cancer resections from 1971 to 2001 with a minimum follow-up of 5 years. The intensity of staining was graded as 0 (no staining), 1 (weak), 2 (intermediate) and 3 (strong). The percentage of cells staining was recorded as 0%, Conclusions GSTP expression is an independent prognostic factor in reduced overall survival in stage C colonic adenocarcinoma.