Dynamic body mass index trajectories are associated with survival outcomes in advanced Hepatocellular Carcinoma...

Obesity paradoxically increases both cancer risk and anti-tumor efficacy. However, the prognostic association of dynamic body mass index (BMI) trajectories in advanced hepatocellular carcinoma (HCC) patients receiving immunotherapy remains underexplored.

This retrospective cohort study included 563 advanced HCC patients treated with anti-PD-1/PD-L1 immunotherapy at the First Affiliated Hospital of Sun Yat-sen University from January 2019 to May 2023. Longitudinal BMI trajectories were modeled using latent class mixed model (LCMM). Survival outcomes were analyzed using Kaplan-Meier, Cox regression, and landmark analyses.

A four-class BMI trajectory model was identified: high-stable (10.3%, median baseline BMI [bBMI]: 27.8 kg/m²), moderate-stable (53.1%, 23.0 kg/m²), moderate-rapid-decline (10.7%, 23.0 kg/m²), and low-slow-decline (25.9%, 20.0 kg/m²). The high-stable group showed superior survival outcomes (median progression-free survival [PFS]: 13.17 months; overall survival [OS]: 32.36 months), while the moderate-rapid-decline group had the worst prognosis (PFS: 4.40 months; OS: 10.87 months). After adjusting for lymph node metastasis, Child-Pugh classification, bBMI, combination therapy, and alpha-fetoprotein (AFP), the hazard ratios (HRs) for PFS in high-stable, moderate-stable, and low-slow-decline groups compared to moderate-rapid-decline were 0.37 (P < 0.001), 0.60 (P = 0.003), and 0.75 (P = 0.151), respectively; for OS, the HRs were 0.25 (P < 0.001), 0.44 (P < 0.001), and 0.73 (P = 0.210). BMI trajectory contributed substantially to survival models.

Dynamic BMI trajectories were associated with survival outcomes in advanced HCC patients receiving immunotherapy, with high-stable patterns showing favorable outcomes. Continuous BMI monitoring may provide a practical prognostic indicator, but prospective validation is required before clinical intervention thresholds can be recommended.