# Prognostic value of the C-reactive protein-albumin-lymphocyte (CALLY) index in surgically treated non-small cell lung cancer

## TL;DR

The CALLY index, a new biomarker combining inflammation, nutrition, and immunity, predicts better survival in surgically treated lung cancer patients.

## Contribution

The study introduces the CALLY index as a novel prognostic biomarker for non-small cell lung cancer.

## Key findings

- The CALLY index showed the highest AUC (0.675) for predicting overall survival in NSCLC patients.
- A high CALLY index was independently associated with improved overall survival in multivariable analysis.
- The association between CALLY index and survival was consistent across different stages and smoking statuses.

## Abstract

The C-reactive protein-albumin-lymphocyte (CALLY) index is a novel composite biomarker integrating systemic inflammation, nutrition, and immunity. It has shown prognostic value in various malignancies. However, its role in non–small cell lung cancer (NSCLC), particularly in surgically treated patients, remains uncertain. Therefore, we evaluated the prognostic value of the CALLY index in comparison with established prognostic markers in patients with resected NSCLC.

We retrospectively analyzed 680 patients who underwent curative-intent surgery for NSCLC. The independent prognostic value of the CALLY index was assessed using Cox proportional hazards models, and its discriminative performance was compared with established inflammatory, nutritional, and immune markers using time-dependent receiver operating characteristic analysis. The optimal cut-off value was determined by maximally selected log-rank statistics based on overall survival (OS). Propensity score matching (PSM) was applied to balance baseline characteristics. OS and recurrence-free survival (RFS) were evaluated using Kaplan–Meier analyses. Stratified Cox analyses and interaction tests were performed by pathological stage and smoking status to evaluate effect consistency of the CALLY index.

The CALLY index yielded the highest area under the curve (AUC = 0.675) for predicting OS among the evaluated markers, indicating relatively better prognostic performance. The optimal cut-off value was 5.14. In multivariable Cox analyses, a high CALLY index remained independently associated with improved overall survival [hazard ratio (HR) 0.40, 95% confidence interval (CI) 0.26–0.64; p < 0.001]. After 1:1 PSM, 208 matched pairs (n = 416) were generated with well-balanced clinical characteristics. Patients with a high CALLY index (>5.14) had significantly longer OS than those with a low index (≤5.14) (log-rank p < 0.001). However, RFS did not differ significantly between two groups (p = 0.701). The associations between the CALLY index and survival outcomes were consistent across pathological stage and smoking status.

The preoperative CALLY index is an independent and accessible prognostic biomarker for OS in resected NSCLC. It may serve as a practical tool for risk stratification, guiding postoperative surveillance and adjuvant treatment planning.