Major prognostic factors of patients with adult T-cell leukemia-lymphoma: a cooperative study. Lymphoma Study Group (1984-1987).

A total of 854 patients with anti-HTLV-I antibody positive ATL, newly diagnosed from 1983 to 1987, were analyzed for prognostic factors. There were 466 males and 388 females with a mean age of 57.1. Of these 269 (31.5%) were alive with a median follow-up time of 14 months from diagnosis, while 585 (65.5%) were dead with a median survival time (MST) of 6 months. MST, and projected 2- and 4-year survival rates of all patients were 10 months, 28% and 12%, respectively. A Cox proportional hazards model analysis revealed that five factors, advanced performance status, high lactic dehydrogenase value, age of 40 years or more, increased number of total involved lesions and hypercalcemia, were associated with shortened survival at P less than 0.01. These factors were used to construct a model to identify patients at three different risks for shortened survival. A group of 178 patients (21.8%) with a hazard ratio of less than 0.5 were classified into the low risk (LR) group, 492 (60.4%) with hazard ratio of less than or equal to 0.5 and less than 2.5 into standard high risk (SHR) group, and 145 (17.8%) with hazard ratio of 2.5 or more extremely high risk (EHR) group. MST, and projected 2- and 4-year survival rates were 37 months, 66.3% and 41.2% for LR, 8 months 20.6%, and 4.5% for SHR, and 2.4 months, 5.6% and 0% for EHR, respectively. The risk grouping is of interest in determining the therapeutic strategy of ATL at diagnosis.