Epidemiology, racial-socioeconomic disparities, and outcomes of T-cell prolymphocytic leukemia: A comprehensive analysis of the SEER database (2000-2021).

e18541 Background: T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive mature T-cell neoplasm. There is limited population level data on T-PLL. This study aims to elucidate the epidemiological characteristics, incidence trends, and survival outcomes of T-PLL using the Surveillance, Epidemiology, and End Results (SEER) database. Methods: Retrospective analysis of Surveillance, Epidemiology, and End Results (SEER) database was performed to elucidate the epidemiological characteristics, incidence trends, and survival outcomes of T-PLL patients. Results: Study included 1092 patients. Median age was 67 years, 65% were of age 65 or more, Males 57% (619/1092), and Females 43% (473/1092). Whites were 74 % (810/1092), African American 13% (13/1092), Hispanic 7% (71/1092), and Asian 3% (36/1092). Age adjusted incidence rate was 0.04 cases per 100,000 person-years. The number of patients newly diagnosed with T-PLL in the first decade from 2000-2010 was 350, whereas from 2011 to 2021 was 742. Patients with T-PLL were distributed in the following income groups: $40,000-$79,000 (55%), $80,000-$119,000 (39%), and only 6% in the > $120,000 income group. Overall, 1- and 5-year relative survival was 59.6% and 17.3%. 5-year relative survival was lower at 12.5% in African Americans as compared to other races (White: 17.6%, Asian: 17.5%, Hispanic: 19.3). 5-year relative survival was affected by income, which was 0% in the lowest quartile income group, followed by 17.6% in the 2nd quartile income group, followed by 15.8% in the 3rd quartile, and 26.4% in the highest quartile income group. 5-year relative survival in urban vs rural population was 16.4% vs 22.9%. Cause of death was available for 633 patients. The most common cause of death was T cell PLL in 41%. The SEER database also reported 16% of deaths from ‘other leukemia; not specified. While this was the listing term captured in the database, these may also have included death from progressive T-PLL. Survival was worse in patients aged > 65 years HR 1.95 (95% CI: 1.44 - 2.63; p < 0.00) and African American race HR 1.40 (95% CI: 1.03 - 1.91; p <0.05). Although survival was adversely affected by lower income, living in urban areas, and female sex, these were not statistically significant. Conclusions: Our SEER database study suggests that T-PLL appeared to be more common among Caucasian race and patients aged > 65 years. The increase in incidence rates and disparities in outcomes based on age, race, and socio-economic status warrant further investigation into the underlying factors and further research to improve equitable care across groups, morbidity, and mortality from this rare and aggressive leukemia.