Post-Doctoral Fellow Daiichi Sankyo, Inc. Manalapan, United States
Background: Adult T-Cell Leukemia/Lymphoma (ATLL) is a rare and aggressive T-cell malignancy whose etiology is associated with human T-cell lymphotropic virus type 1 (HTLV-1) infection. The estimated overall HTLV prevalence is 0.1% - 0.2% in the United States (US) (Chang et al., 2014). Fewer than 7% of HTLV-1 infections lead to malignancy (Satake et al., 2015). ATLL has a grim prognosis. Previous large, retrospective analysis has shown a 5-year overall survival among adults of 14% despite treatment (Bazarbachi et al., 2010). Patterns of incidence and prevalence of ATLL in the US are not known.
Objectives: To estimate the overall, age-, sex-, and race-specific incidence and prevalence of ATLL in the US.
Methods: US Surveillance, Epidemiology, and End Results (SEER) 21 Registries, Nov. 2020 (2000-2018) were queried using SEER*Stat software (v8.4.0.1). SEER estimates were applied to the age-, gender- and race-specific 2020 US Census Bureau population data.
Results: The estimated annual incidence of ATLL in the US was 0.06 per 100,000 which corresponds to an estimated 210 new cases of ATLL diagnosed in the US every year. The incidence of ATLL increases with age, ranging from 0.0045 to 0.2455 per 100,000 in the 01-04 years and 80-84 years age groups, respectively. 77% of the cases are diagnosed after the age of 50 years. Age-specific annual incidence was nearly identical between males and females, but higher among black Americans (22% higher than Whites). There were an estimated 224 and 364 patients with ATLL who were diagnosed in the last 5- and 10-years, respectively, and were still alive (5- and 10-year prevalence). ATLL prevalence varies by sex, with 10-year prevalence in males (223) higher than females (141) (M:F=1.6). The estimated 10-year ATLL prevalence in Whites and Blacks was 204 and 130 respectively.
Conclusions: ATLL is a rare disease with an estimated 10-year US prevalence of 364. It is an aggressive cancer with most patients dying within 5 years of their diagnosis. These results highlight a significant unmet medical need for their treatment and improving their survival.
