Background: The goals of this study are to describe the frequency, clinical characteristics, and outcome of the different non-Hodgkin's lymphomas according to age.
Patients and methods: Patients included in the recently published analysis of the Non-Hodgkin's Lymphoma Classification Project were analyzed. All patients had their slides reviewed and classified by five independent expert hematopathologists. Lymphomas were classified according to the Revised European American Classification of lymphoid neoplasms. Sufficient data were available on 1283 cases. Five age groups were analyzed: < 35 years, 35-49 years, 50-59 years, 60-69 years, and > or = 70 years.
Results: Few differences were observed between the age groups with regard to lymphoma types and clinical characteristics. Anaplastic large cell lymphoma, Burkitt's lymphoma, and lymphoblastic lymphoma were observed more frequently in patients younger than 35 years, whereas small lymphocytic and lymphoplasmacytoid lymphomas were observed more frequently in patients older than 70 years. Mantle cell lymphoma and marginal zone lymphomas were observed more frequently in middle-aged patients. Poor performance status was more frequent in older patients, as was bone marrow infiltration, whereas spleen involvement was more frequent in younger patients. Young and older patients had a slightly worse age-adjusted International Prognostic Index score (P < 0.01). Complete response rates decreased with age from 68% in the youngest patients to 45% in the oldest patients (P < 0.0001). Median event-free survival and overall survival also decreased with age (P < 0.0001).
Conclusions: Elderly patients have a poorer outcome than younger patients but age alone is not sufficient to discriminate patients with a poor outcome. However, the histologic type of lymphoma and clinical characteristics may define a subgroup of patients with a poor outcome in each age category.