Epidemiology and Prognosis of T-Cell Lymphoma

Abstract

T/NK-cell lymphoid neoplasms account for approximately 6 % of all lymphoid neoplasms. While the incidence rates of many B-cell lymphomas have begun to decline in the United States (US) in recent years, incidence rates for T-cell lymphomas have continued to rise. The causes of the majority of T-cell lymphomas remain unexplained. T-cell lymphomas comprise multiple subtypes and their distinct descriptive epidemiology—e.g., striking differences between incidences of T-cell lymphoma subtypes by age, over time and by race/ethnicity—likely reflect their distinct etiologies (e.g., celiac disease and extranodal T-cell lymphomas; human T-cell lymphotropic virus I (HTLV-1) and adult T-cell leukemia/lymphoma). Differences in T-cell lymphoma subtypes further extend to their clinical characteristics and care; they each have differential treatment, survival and prognosis. The rarity of T-cell lymphomas has historically posed challenges for furthering our understanding of these tumors, particularly as we now understand that each T-cell lymphoma subtype requires investigation independently. However, we expect important clues to emerge as on-going large international consortium efforts aim to accrue sufficient sample sizes of T-cell lymphomas and its subtypes for both etiological and prognostic studies.