Southwest oncology group clinical trials for intermediate-and high-grade non-hodgkin's lymphomas

Previous studies have established CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) as the standard of comparison for treatment programs for patients with advanced stages of aggressive non-Hodgkin's lymphomas. Three sequential CHOP studies conducted by the Southwest Oncology Group (SWOG) showed a complete remission (CR) rate of 53% for 418 patients. This rate did not vary among the three studies. Median age was over 55 years. Relapse-free survival of CRs plateaued at 4 to 5 years. Approximately 21% of all patients in the first study and 33% of all patients in the following two studies are long-term survivors and presumed cured. Survival was clearly a function of patient age. Approximately 45% of all patients under age 55 at the time of treatment are cured by CHOP chemotherapy. To determine the toxicity, CR rate, and patient survival of m-BACOD (methotrexate, bleomycin, doxorubicin, cyclophosphamide, vincristine, dexamethasone), ProMACE-CytaBOM (prednisone, methotrexate, doxorubicin, cyclophosphamide, etoposide, cytarabine, bleomycin, vincristine, methotrexate), and MACOP-B (methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone, bleomycin), SWOG initiated a series of phase II studies. Of 118 eligible patients in the m-BACOD study, the median age of 85 patients treated with the full-dose regimen was 54 years, while the median age of 33 patients who started therapy at reduced doses was 67 years. Fatal toxicity was observed in 6% of patients receiving full doses and 13% of those receiving reduced doses. Life-threatening toxicity occurred in 31% of patients on the full-dose regimen and 34% on the reduced-dose regimen. CR was 65% for full-dose treatment, but 27% for reduced doses. Of the 83 evaluable patients in the ProMACE-CytaBOM study, the median age was 54 years. Fatal toxicity was observed in 5% of all patients, and life-threatening toxicity occurred in 16%. CR rate in 79 patients evaluated for response is 58%. Results from 131 patients entered into the MACOP-B study are currently being analyzed. A large-scale, randomized comparative study of these four treatment programs was recently undertaken to determine if the newer regimens are superior to standard CHOP therapy and how they compare with each other in terms of toxicity, cost, and therapeutic effectiveness.