Association between obesity and cancer risk in adults with HIV in Korea

Introduction: This study aimed to investigate the association between obesity and cancer risk as well as site-specific cancer risks in adults with HIV using a nationwide health screening database in Korea. Methods: Of the 16,671 adults with a new diagnosis of HIV from 2004 to 2020, 456 incident cancer cases and 1814 individually matched controls by sex, year of birth, year of HIV diagnosis, and follow-up duration (1: 4 ratio) were included in this nested case–control study. The association between obesity (BMI ≥25 kg/m²) and cancer risks was estimated and presented as odds ratios (ORs) and 95% confidence intervals (95% CIs). Results: Of the 456 cancer incident cases, there were 146 AIDS-defining cancer cases and 310 non-AIDS-defining cancer cases. Compared with nonobese adults with HIV, obese adults with HIV were at higher risk of non-AIDS-defining cancer (OR = 1.478, 95% CI = 1.118–1.955). Otherwise, the overall risk of AIDS-defining cancer (OR = 0.816, 95% CI = 0.520–1.279) and each type of AIDS-defining cancer (Kaposi sarcoma and non-Hodgkin’s lymphoma) were not high in obese adults with HIV. Of the specific types of non-AIDS-defining cancers, obesity was associated with an increased risk of colorectal cancer (OR = 3.090, 95% CI = 1.110–8.604) and liver, bile duct, and pancreatic cancers (OR = 2.532, 95% CI = 1.141–5.617). Conclusion: Obesity, which is one of the important health concerns in HIV management, was associated with an increased risk of non-AIDS-defining cancer but not AIDS-defining cancer.