Clinical Relevance of the CALLY Index in Prognostic Stratification of Intrahepatic Cholangiocarcinoma

Recent investigations have highlighted the prognostic significance of the C-reactive protein-albumin-lymphocyte (CALLY) index across various malignancies. However, its prognostic relevance in patients with intrahepatic cholangiocarcinoma (ICC) treated with surgical resection remains to be fully clarified. This study aimed to evaluate whether the prognostic significance of preoperative CALLY index for long-term outcomes in patients with intrahepatic cholangiocarcinoma undergoing surgical resection.

We retrospectively examined 131 patients who underwent curative-intent hepatectomy for ICC between January 2007 and June 2022. The optimal cutoff value of the CALLY index for predicting overall survival (OS) was identified using the minimum p-value method. Clinicopathological features and survival outcomes were then compared between patient groups with high and low CALLY index, and multivariate statistical analyses were subsequently performed to determine independent prognostic indicators.

The median preoperative CALLY index was 3.5 (interquartile range=1.1-10.1). A cutoff value of 3.0 best stratified OS, classifying 73 patients into the high CALLY group and 58 into the low CALLY group. Patients with CALLY ≤3.0 had significantly poorer disease-free survival (DFS) and OS compared with those with CALLY >3.0 (5-year DFS: 27.1% vs. 49.7%, p<0.001; 5-year OS: 31.2% vs. 62.2%, p=0.003). Multivariate analysis, using pre/intra-operative variables, confirmed a low CALLY index as an independent predictor of both DFS (hazard ratio=2.05, p=0.004) and OS (hazard ratio=1.79, p=0.046).

A preoperative CALLY index threshold of 3.0 provides significant prognostic discrimination in patients undergoing resection for ICC. This easily measurable biomarker may serve as a valuable tool for prediction of long-term outcomes in clinical practice.