Purpose: We reviewed survival data of patients with low-grade lymphoma entered on Southwest Oncology Group (SWOG) lymphoma trials in 1972 to 1983 to determine the utility of doxorubicin-containing therapy (cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP]) in such patients.
Patients and methods: We identified all patients with low-grade lymphoma, no prior therapy, and stage III or IV disease who were treated with full-dose CHOP induction therapy on any arm of SWOG studies 7204, 7426, or 7713. Survival data for this group of patients were correlated with pretreatment prognostic factors, including histology, patient age, sex, symptom status, performance status, bone marrow or extranodal involvement, and the number of disease sites. The effect of maintenance treatment was also assessed.
Results: Four hundred fifteen patients met criteria for inclusion in the study group. With median follow-up periods of 12.8 years (maximum, 19.8 years), the median survival duration was 6.9 years. Survival was significantly shorter in patients with follicular mixed or small lymphocytic histology, age greater than 40 years, male sex, B-symptom status, and SWOG performance status greater than 1. Multivariate regression analysis showed histology, age, and sex to be independent predictors of survival. There was no definite survival plateau of cured patients in any subgroup, although the survival curve for follicular mixed histology patients showed long-term survival of approximately 25%. Maintenance therapy did not prolong survival.
Conclusion: Doxorubicin-containing treatment did not prolong the overall median survival of low-grade lymphoma patients compared with results with less-aggressive programs.