Higher inflammatory response in hepatocellular carcinoma is associated with immune cell infiltration and a better outcome.

Abstract

Hepatocellular carcinoma (HCC) often develops from chronic liver inflammation. Inflammation within a tumor can either promote cancer progression or activate an immune response against it. This study aims to determine the clinical significance of enhanced inflammation in HCC. Data from 655 HCC patients across four cohorts (TCGA, GSE6764, GSE76427, GSE89377) were examined. Inflammatory response was quantified using a scoring system derived from the gene set variation analysis of the "INFLAMMATORY_RESPONSE" gene set. A stepwise increase in inflammatory response was noted from normal liver to cirrhosis, with consistently lower levels in HCC across both GSE6764 and GSE89377 cohorts (both p < 0.001). Similar trends were observed in interferon response, pathways such as IL6/JAK/STAT3 and complement signaling, coagulation cascade, and allograft rejection (all p < 0.02). HCCs with high inflammatory response were associated with increased immune cell infiltrations (p < 0.01) and cytolytic activity (p < 0.001). Interestingly, these HCCs had reduced mutation rates, no relationship with cell proliferation, and displayed both immune responses and pro-cancerous signals including epithelial-mesenchymal transition, KRAS, and hypoxia. Further, a high inflammatory score correlated with improved disease-free survival in TCGA (p = 0.034) and overall survival in GSE76427 (p = 0.008). HCC with higher levels of inflammatory response demonstrated increased immune cell infiltration, enhanced immune-related and other pro-cancerous-related signaling, and showed a trend toward a better patient prognosis.