Host Index and Gallbladder Cancer: An Emerging Prognostic Biomarker.

Background And Objectives: There is emerging evidence that host related variables predict outcomes in various cancers. The Host index (H-index) incorporates various host-related, blood-derived biomarkers (immunological and nutritional parameters) as a single mathematical formula. The aim of this study was to evaluate outcomes using the H-index as a prognostic marker in gallbladder cancer (GBC) patients undergoing curative resection.

Methods: Retrospective cohort study of surgically treated GBCs at a tertiary cancer centre from January 2010 to May 2023 was performed. Patients who had received neoadjuvant therapy, metastatic (M1) disease at time of surgical exploration and incidental GBCs were excluded. Baseline neutrophil, lymphocyte, monocyte and platelet counts, hemoglobin and albumin levels were recorded. H-index was computed and analysed.

Results: 241 curatively resected GBC patients were included. The H-index was inversely associated with disease free survival (DFS), both on univariate (79.7 vs. 61.4% for H-index  3.4 respectively; p = 0.046) and multivariate analysis (Hazard ratio [HR] for recurrence: 1.954 [95% C.I.: 1.366-2.796]; p = < 0.001). Using the maximally distributed rank statistics, a cut-off of 1.31 showed a significant difference in 3-year DFS (86.2 vs. 68.4% for H-index  1.31 respectively; HR: 2.21 [95% CI: 1.16-4.21]; p = 0.013) but not overall survival (OS) (p = 0.269).

Conclusion: A higher H-index predicted for worse DFS in curatively resected GBC patients. This shows host related variables do play a role in influencing outcomes in GBC. However, larger prospective studies are required to further strengthen this finding.

Summary: Host-related, blood derived biomarkers can influence outcomes in various solid tumours. A higher baseline Host index (H-index) value which incorporates various blood-derived biomarkers, predicted for worse disease-free survival in curatively resected gallbladder cancers.