Prognostic value of GST-[pi] expression in diffuse large B-cell lymphomas

Among mechanisms potentially involved in resistance to alkylating agents and anthracyclines, the glutathione system has been extensively studied in vitro. We analyzed by immunohistochemistry the relation between glutathione s-transferase pi (GST-pi) expression in tumor cells and outcome in 69 cases of diffuse large B-cell NHL (DLBCL). GST-pi expression was considered as low when /=50% tumor cells were stained. Median follow-up was 58 months. GST-pi expression was correlated with the probability of achieving complete remission (CR). Patients with high GST-pi expression had a worse 5-year freedom from progression (FFP). High GST-pi expression was associated with a trend for lower survival. In the group of patients with International Prognostic Index (IPI) 0-1, low GST-pi expression was associated with a CR rate of 88%, a 5-year FFP of 76+/-20% and a 5-year survival of 78+/-16% compared to 36, 14+/-16 and 40+/-32%, respectively, in patients with a high GST-pi expression (P=0.002, P&