Treatment of diffuse poorly differentiated lymphocytic lymphoma. An analysis of prognostic variables.

Forty patients with diffuse poorly differentiated lymphocytic lymphoma (DPDL) Stages II-IV were treated with three different and successive combination chemotherapy protocols. Seventeen patients were treated with the cyclophosphamide (CTX) L2 protocol which included maintenance chemotherapy for 3 years. Only three patients were treated with the NHL-3 (non-Hodgkin's lymphoma) protocol, and 20 patients received the NHL-5 program. All protocols included radiotherapy (1500-4800 rad) to areas of initial bulky disease or persistent tumor, as well as central nervous system (CNS) prophylaxis with intrathecal methotrexate in patients with bone marrow involvement. Seventy-eight percent of local recurrences occurred in previously irradiated areas. Two-year survival rates were 55% and 70% for the CTX-L2 and NHL-5 protocols, respectively. Median disease-free survival for 24 complete response (CR) patients was 16.5 months. Of the 40 patients, 37 were evaluable for response to therapy. The CTX-L2 produced an 80% total response (TR) rate, a 60% CR, and a 20% partial response (PR). The patients on the NHL-5 achieved a TR rate of 95%, 74% CR, and 21% PR. Differences in TR and CR between the two protocols were not significant. Only 1 of 3 patients on the NHL-3 protocol achieved a CR. There was a trend for age greater than 50 years to lessen the chances of CR (P = 0.091); however, sex, symptoms, stage of disease, and LDH level were not significantly related to CR rate. Response to treatment (CR versus PR versus failure) was the most important factor influencing survival (P less than 0.001); age (greater than 50 years) was also significant (P = 0.008). Lactate dehydrogenase (LDH) was of borderline significance (P = 0.06). Cox regression model showed age (greater than 50 versus less than 50 years, P = 0.001), LDH (greater than 500 versus less than or equal to 500 U/L, P = 0.019) and symptoms (A or B) to be the best predictors of survival.