Clinical Outcomes of Patients with Adult T Cell Leukemia-Lymphoma in a Nonendemic Metropolitan Area: A Retrospective Analysis of the Population-Based Osaka Cancer Registry

Adult T cell leukemia-lymphoma (ATL) is a mature T cell malignancy associated with human T cell leukemia virus type I (HTLV-1), a retrovirus that is endemic in southwestern Japan. Because of population migration, cases of ATL are expected to increase in nonendemic areas. Here, to clarify the outcomes of patients with ATL in the nonendemic metropolitan area of Osaka, we retrospectively analyzed data from the population-based Osaka Cancer Registry from 2010 to 2015. This analysis included 91 patients age ≤70 years who received chemotherapy for ATL. With a median follow-up of 988 days in surviving patients, the probability of 2-year overall survival (OS) was 21.9% (95% confidence interval [CI], 14.1% to 30.9%) and the median OS was 9.8 months (95% CI, 7.3 to 13.5 months). The probability of 2-year OS was 22.2% in the nontransplant group (n = 63) and 21.4% in the transplant group (n = 28), without a statistically significant difference between the 2 groups. Allogeneic transplantation was not a favorable prognostic factor in patients with ATL in propensity score-adjusted analysis (P = .86, log-rank test). More clinical studies are needed to improve the clinical outcomes of patients with ATL in nonendemic areas.