Epidemiological trends of lymphoma in Sri Lanka: A national cancer registry study (2005-2021)

Globally, lymphoma incidence has been steadily rising, with notable regional and gender-based variations. Understanding these trends in developing countries like Sri Lanka is essential to address cancer control strategies.

Cancer incidence and mortality data from the National Cancer Control Program (NCCP) registries (2005-2021) were analyzed. Temporal trends in age-standardized rates (ASR) were assessed using Joinpoint Regression to estimate annual percent change (APC) and average APC (AAPC).

A total of new 15,577 lymphoma cases were reported with male predominance (60 %, n = 9346) and non-Hodgkin lymphoma (NHL) being the predominant subtype (79 %, n = 9561). The overall incidence increased significantly over 16 years (AAPC: 4.1 %; p < 0.05), with a 1.4-fold rise in both sexes and a marked rise among 0-19-year-olds, exclusively post-2019 (p < 0.05). NHL incidence was highest in individuals aged ≥ 60 years, with a 2-fold rise in both gender (APC: 3.2; 95 % CI: 0.4 - 6.1; p < 0.05) during 2011-2021. Hodgkin lymphoma (HL) showed a significant 3-fold increase in females, while trends in males fluctuated, with a significant average AAPC in both sexes from 2011 to 2021 (p < 0.05). Despite the non-significant rise in female incidence across most age groups, males in 40-59 and > 60 years age groups showed a decline. A significant rise in NHL-related deaths among males (p < 0.05) was noted, with a non-significant increase in females.

Our findings indicate an apparent rising burden of lymphoma in Sri Lanka, particularly among males and the elderly. However, this observed increase may be partly attributable to improvements in cancer diagnostics and NCCP reporting over time. Additionally, evolving WHO classifications and their gradual adoption may also have influenced the observed trends.