Effect of age on therapeutic outcome in advanced diffuse histiocytic lymphoma: the Southwest Oncology Group experience.

To study the influence of chronologic age on treatment outcome in patients with advanced, diffuse large-cell (histiocytic) lymphoma (DHL), we reviewed the results of two recent Southwest Oncology Group (SWOG) clinical trials. From 1974 to 1982, members entered 307 eligible patients treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) with or without bleomycin, and CHOP with or without immunotherapy using BCG, levamisole, or both. Complete response (CR) rates declined progressively with advancing age: 65% in those under 40, 60% in the 40 to 54 age group, 55% in the 55 to 64 age group, and 37% in those 65 and older (P = .001). Likewise, survival decreased significantly in older patients: medians were 101 +, 52, 34, and 16 months, respectively (P less than .001). Treatment guidelines included an initial dose reduction of 50% for patients aged 65 or older and for younger patients with bone marrow compromise. Despite protocol specifications, 23 of 81 patients aged 65 or older received initial full-dose therapy. When these patients were compared with younger patients on whom full-dose chemotherapy was started, survival curves, but not CR rates, were still significantly different. There were no significant differences in duration of CR or frequency of treatment complications. These data suggest that older age is associated with a worse prognosis in advanced DHL. Moreover, the initial dose reduction for patients aged 65 or older may have contributed to their inferior outcomes.