Body mass index and serum alpha-fetoprotein level associated with PD1 expression and prognosis in patients with hepatocellular carcinoma.

Background: Many factors affect the outcome of treatment with programmed death 1 (PD1) inhibitors for hepatocellular carcinoma (HCC). The objective of this study was to investigate the associations of clinicopathological parameters with PD1 expression and HCC prognosis.

Methods: A total of 372 HCC patients (Western population) from The Cancer Genome Atlas (TCGA), and 115 primary HCC tissues and 52 adjacent tissues (Dataset GSE76427, Eastern population) from Gene Expression Omnibus (GEO) database were enrolled in this study. The primary outcome was 2-year relapse-free survival. Kaplan-Meier survival curves with the log-rank test were used to analyze the differences in prognosis between the two groups. X-tile software was used to confirm the optimal cut-off for clinicopathological parameters while assessing the outcome. Immunofluorescence was performed on HCC tissues to evaluate PD1 expression.

Results: Expression of PD1 was up-regulated in tumor tissue from both TCGA and GSE76427 patients, which positively correlated with body mass index (BMI), serum alpha-fetoprotein (AFP) level, and prognosis. Patients with higher PD1, lower AFP, or lower BMI had longer overall survival than those with lower PD1, higher AFP, or higher BMI, respectively. AFP and PD1 expression were validated in 17 primary HCC patients from the first affiliated hospital, Zhejiang University School of Medicine. Finally, we confirmed longer relapse-free survival with higher PD1 or lower AFP.

Conclusion: The findings indicate that BMI and AFP are associated with PD1 expression and HCC prognosis, offering insight for clinical management and personalized immunotherapy for HCC.