Trends in the Incidence of Kaposi's Sarcoma and Non-Hodgkin Lymphoma in Northern Thailand during the Time Period of Universal Access to Antiretroviral Treatment, 1998-2017.

Purpose: We evaluated the trends in incidence of Kaposi's sarcoma (KS) and Non-Hodgkin's lymphoma (NHL)  over the two decades in northern Thailand during which access to antiretroviral treatments (ART) in Thailand was scaled up.

Methods: This is retrospective observational study. Data from 1998 to 2017 of patients diagnosed with KS and NHL from three long-standing, population-based cancer registries in northern Thailand (Chiang Mai, Lampang and Lamphun) were used to describe trends in age-adjusted incidence rate (ASR) of these cancers. The annual percent change (APC) of incidence rates were evaluated over this timeframe.

Results: The incidence of KS significantly increased from 1998 to 2017 in males (APC of 6.9%) and very low incidence for evaluating change in female. NHL incidence significantly increased from 1998 to 2017, 2.2% and 1.8% per year in males and females, respectively (p<0.001).

Conclusion: In the last two decades, the incidence of KS in male and NHL in both sexes have increased in northern Thailand, while the incidence of KS in female remained low. The change in incidences in opposite to the decline in HIV prevalence and increase ART coverage rate supported that other associated factors attributable to the development of KS and NHL should be looked for i.e., environmental, occupational exposures and other infections.