Trends in Cancer Diagnoses Among People Living with HIV: A 20-Year Retrospective Study from a Tertiary Center in Thailand

<b>Background</b>: Cancer epidemiology data for people living with human immunodeficiency virus (PLWH) in Thailand, particularly in the era of combination antiretroviral therapy (ART), remain limited. In this study, we describe the prevalence, temporal trends, clinical characteristics, and survival outcomes of patients with AIDS-defining cancers (ADCs) and non-AIDS-defining cancers (NADCs). <b>Methods</b>: We retrospectively reviewed adult PLWH diagnosed with malignancy at Songklanagarind Hospital in Thailand during 2003-2023. Demographic, human immunodeficiency virus (HIV)-related, and clinical data were analyzed using chi-square and Wilcoxon rank-sum tests and the Kaplan-Meier method. <b>Results</b>: Among 444 patients, 231 had NADCs and 213 had ADCs. The NADC proportion increased markedly over time. Common ADCs included non-Hodgkin lymphoma and cervical cancer; common NADCs included lung cancer, non-nasopharyngeal head and neck cancer, and hepatocellular carcinoma. Compared with patients with ADCs, those with NADCs were older, more often male, and had higher proportions of undetectable HIV viral load, CD4 counts ≥200 cells/µL, and ART use. Approximately one-third of patients presented with advanced-stage disease, and the median overall survival was 15.9 months. <b>Conclusions</b>: Over two decades, NADCs have become the predominant malignancy in Thai PLWH, associated with older age, male sex, and improved immune function. This reflects the evolving cancer risk in the era of combination ART. We suggest employing multidisciplinary approaches involving HIV and cancer care to improve survival outcomes and integrating age-appropriate screening for common NADCs into HIV care.