522 Background: Body mass index (BMI) is a recognized risk factor for hepatocellular carcinoma (HCC), but its relationship to stage at diagnosis, survival, and the “obesity paradox” remains uncertain. Methods: We analyzed Renown Health patients with HCC. Median BMI was calculated in two windows: 0–60 days prior to diagnosis and 1–10 years prior. Logistic regression tested associations between BMI and stage (early I–II vs. late III–IV), adjusting for age, sex, viral hepatitis, and alcohol use. Cox proportional hazards models assessed associations with all-cause mortality. We also evaluated whether frequency of BMI monitoring related to stage at diagnosis. Results: Among 82 staged patients, 62.2% experienced BMI decline between time windows, with a median decrease of 3.2%. Obesity within 60 days of diagnosis was associated with reduced odds of late-stage HCC (adjusted OR 0.30, 95% CI 0.09–0.89), whereas BMI measured years prior showed no association. In 343 patients with sufficient prior medical record, obesity near diagnosis was associated with improved survival (HR 0.69, 95% CI 0.48–0.98). In contrast, weight loss prior to diagnosis predicted poorer survival: HR 1.08 (95% CI 1.01–1.14) per 1-point BMI decrease, HR 1.11 (95% CI 1.01–1.21) per 5% decrease, and HR 1.87 (95% CI 1.20–2.92) for patients transitioning from obese to non-obese. Diagnostic checks suggested these effects were most pronounced in the first 6 months after diagnosis. Frequency of BMI monitoring was not associated with stage at presentation. Conclusions: Obesity at the time of HCC diagnosis, but not years earlier, was associated with earlier stage and improved survival, while pre-diagnosis weight loss predicted worse outcomes, particularly within the first months after diagnosis. These findings suggest that apparent survival benefits of obesity may partly reflect occult weight loss as a marker of aggressive disease, contributing to the broader discussion of the obesity paradox in cancer. Limitations include lack of reliable cirrhosis severity data, which may confound associations between BMI and outcomes. These findings may contribute to the “obesity paradox” discussion in cancer outcomes, in which obesity appears to increase cancer risk overall but paradoxically appears to offer survival protection after diagnosis. Additionally, further studies are needed to investigate this relationship. If validated, consideration should be made as to whether BMI at diagnosis could play a role in both prognostic discussions and risk stratification in HCC.
Ermi et al. (Sat,) studied this question.