A critical analysis of prognostic factors in North American patients with human T-cell lymphotropic virus type-1-associated adult T-cell leukemia/lymphoma: a multicenter clinicopathologic experience and new prognostic score.

Background: To define the clinicopathologic and prognostic features of patients with human T-cell lymphotropic virus type-1 (HTLV-1)-associated adult T-cell leukemia/lymphoma (ATLL) in North America, standard criteria were used to identify patients with ATLL.

Methods: Statistical analyses used included descriptive statistics, Kaplan-Meir survival analysis, and recursive partitioning.

Results: Eighty-nine patients were identified between August 1992 and May 2007, including 37 (41.6%) males and 52 (58.4%) females with a median age of 50 years (range, 22-82 years). All but 6 patients had immigrated to the United States from the Caribbean, Latin America, or Africa. The acute subtype predominated (68.5%). The majority of patients received a combination-alkylator-based chemotherapy regimen in the front-line setting (72.6%). The most common regimen was cyclophosphamide, doxorubicin, vincristine, and prednisone at standard doses or attenuated and/or with methotrexate (CHOP-like), which produced an overall response rate of 64.1%. Despite initial responses to therapy, the median overall survival for all subtypes was 24 weeks (range, 0.9-315 weeks). Although the International Prognostic Index and Prognostic Index for peripheral T-cell lymphoma unspecified identified subsets of patients, these models were not completely predictive. A recursive partitioning analysis was performed on the data, which successfully identified 3 prognostic categories based on Eastern Cooperative Oncology Group performance status, stage, age, and calcium level at diagnosis.

Conclusions: This series proposed a new prognostic model for patients with HTLV-1-associated ATLL and confirmed a poor outcome for these patients in North America.