The CALLY index as a comprehensive inflammation-nutrition-immunity marker for prognosis in gastric cancer surgery.

[BACKGROUND] Reliable preoperative prognostic tools that comprehensively reflect host-related factors remain limited for gastric cancer (GC). The C-reactive protein-albumin-lymphocyte (CALLY) index integrates systemic inflammation, nutritional status, and immune competence. We evaluated its prognostic performance compared with commonly used inflammation-nutrition indices.

[METHODS] We conducted a single-center retrospective cohort study of consecutive patients undergoing curative gastrectomy for gastric adenocarcinoma, with temporal validation. Preoperative laboratory parameters obtained within 1 week before surgery were used to calculate the CALLY index. Outcomes included overall survival (OS), disease-free survival (DFS), and 30 day postoperative morbidity. Discrimination was assessed using receiver operating characteristic (ROC) analysis; survival outcomes were analyzed using Kaplan-Meier methods and multivariable Cox regression; postoperative morbidity was evaluated using multivariable logistic regression.

[RESULTS] The development cohort included 992 patients, and the temporal validation cohort included 302 patients. In the development cohort, the optimal CALLY cutoff was 2.61. For 5 year OS, the CALLY index showed the highest discriminative ability (AUC = 0.708), comparable to mGPS (AUC = 0.705) and superior to other indices (AUC ≤ 0.675). A low CALLY index was significantly associated with poorer OS and DFS (both p < 0.001) and remained independently prognostic after multivariable adjustment (OS HR 1.56, 95% CI 1.20-2.03; DFS HR 1.48, 95% CI 1.16-1.90). Low CALLY was also independently associated with increased risks of overall and severe postoperative complications, with consistent directions observed in the validation cohort.

[CONCLUSIONS] The preoperative CALLY index independently predicts long-term survival and short-term postoperative morbidity in patients with GC undergoing curative gastrectomy. Compared with conventional inflammation-nutrition scores, CALLY shows comparable-to-slightly better and more consistent prognostic performance across endpoints, although absolute gains in discrimination are modest. Prospective multicenter validation with standardized assays, prespecified analyses, and recalibration is warranted.