Epidemiology and survival trend of adult T-cell leukemia/lymphoma in the United States

Background: Globally, 5 million to 10 million people are infected with human T-cell leukemia virus type 1, which causes adult T-cell leukemia/lymphoma (ATLL) in 2% to 5% of the carriers. ATLL is a rare but extremely aggressive malignancy that can be challenging to diagnose. Very little data exist on the incidence patterns of ATLL in the United States. Methods: ATLL cases reported to the National Program of Cancer Registries, the Surveillance, Epidemiology, and End Results (SEER) program, and the New York State Cancer Registry were used for the study. Age-adjusted incidence rates were calculated by age, race/ethnicity, sex, and year of diagnosis. The 5-year survival rate was compared among race/ethnicity groups with the SEER data. Results: During 2001-2015, 2148 ATLL cases were diagnosed in the United States, 18% of which were in New York State. New York State had the highest incidence rate for ATLL, with a rising trend especially among non-Hispanic blacks (NHBs), whereas the incidence was stable across the remainder of the United States. NHBs were diagnosed at a younger median age (54 years) and had a shorter overall survival (6 months). In New York City, only 22.6% of the ATLL cases diagnosed were born in North America. Conclusions: This is the largest epidemiological study of ATLL in the United States and shows a rising incidence in New York City. NHBs have a younger age at presentation and poor overall survival. The rising incidence is largely due to NHBs originating from the Caribbean.