Associations between changes in MASLD status and cancer development in young adults: A nationwide cohort study

Metabolic dysfunction-associated steatotic liver disease (MASLD) is increasingly prevalent among young adults and may contribute to cancer development. However, the impact of longitudinal changes in MASLD status on cancer risk remains unclear. This study aimed to evaluate the association between changes in MASLD status and subsequent cancer incidence in young adults.

Adults aged 20-39 years who underwent two consecutive health screening examinations-one between 2009-2012 and another between 2011-2014-were identified from the Korean National Health Insurance Service database. Participants were classified into four groups based on changes in MASLD status: non-MASLD, resolved MASLD, incident MASLD, and persistent MASLD. Cox proportional hazards models were used to calculate adjusted hazard ratios (HRs) and 95 % confidence intervals (CIs) for the development of cancer.

During a median follow-up of 10.6 years, 95,666 (2.7 %) of 3536,172 participants developed cancer. Compared with the non-MASLD group, the persistent MASLD group exhibited the highest overall cancer risk (HR = 1.15; 95 % CI = 1.13-1.18), followed by the incident MASLD group (HR = 1.03; 95 % CI = 1.00-1.06). The resolved MASLD group showed no significant difference in cancer risk (HR = 1.02; 95 % CI = 0.98-1.05). Persistent MASLD was further associated with elevated risks of laryngeal, biliary, renal, hepatic, pancreatic, and colorectal cancers. Among women, persistent MASLD was linked to higher risks of uterine corpus, cervical, and ovarian cancers.

Incident and persistent MASLD in young adults are associated with increased overall and site-specific cancer risks, whereas individuals whose MASLD improved showed no significant excess risk. Early identification and management of MASLD may help reduce future cancer burden.