Abstract
BACKGROUND: Digestive system cancers remain a leading cause of cancer-related mortality globally, underscoring the need for reliable prognostic tools. The C-reactive protein-Albumin-Lymphocyte (CALLY) index, which reflects inflammation, nutrition, and immunity, has shown potential in predicting survival. However, comprehensive evaluations of its role in digestive system cancers are still limited. METHODS: A meta-analysis of English-language studies from online databases was performed to assess the prognostic value of the CALLY index. Pooled hazard ratios (HRs) were calculated for overall survival (OS), disease-free survival (DFS), recurrence-free survival (RFS), and cancer-specific survival (CSS). RESULTS: A total of eighteen articles (19 studies, encompassing 7,951 patients) were included. A lower CALLY index was significantly associated with poorer outcomes across all survival endpoints. The pooled HR for OS was 1.973 (95% CI: 1.734-2.244), with HRs for DFS, RFS, and CSS being 2.093 (95% CI: 1.682-2.604), 1.462 (95% CI: 1.292-1.654), and 2.456 (95% CI: 1.887-3.221), respectively (all P < 0.001). Subgroup analyses for OS demonstrated consistent prognostic significance across various treatment strategies, cancer types, cutoff values, sample sizes, and regions. Notably, the CALLY index was a strong predictor of OS in surgical patients (HR = 2.014, 95% CI: 1.794-2.260, P < 0.001). Sensitivity analyses validated the robustness of these findings, with minimal publication bias (Egger's test P = 0.053). CONCLUSIONS: The CALLY index serves as a cost-effective and reliable biomarker for predicting prognosis in digestive system cancers. Its utility as a pre-treatment risk stratification tool, which integrates key factors of inflammation, nutrition, and immunity, renders it valuable for guiding clinical decision-making.