Impact of the CALLY Index in Predicting Overall Survival and Disease-Free Survival in Patients Undergoing Radical Cystectomy for Muscle-Invasive Bladder Cancer.

Background: Muscle-invasive bladder cancer (MIBC) is associated with poor survival outcomes despite radical cystectomy (RC), creating a clinical need for simple and reliable prognostic biomarkers.

Aim: The CALLY index, a composite biomarker derived from serum C-reactive protein (CRP), albumin, and lymphocyte counts, reflects systemic inflammation, nutritional status, and immune function. Its prognostic utility in MIBC has not been fully elucidated. To evaluate the prognostic value of the CALLY index in predicting overall survival (OS) and disease-free survival (DFS) in patients undergoing RC for non-metastatic MIBC.

Methods: In this retrospective cohort study, 134 patients who underwent RC for non-metastatic MIBC between February 2014 and January 2024 were included. Patients who received neoadjuvant chemotherapy, had secondary malignancies, or active infections were excluded. The CALLY index was calculated as follows: (Albumin [g/dL] × Lymphocyte count [10⁹/L])/CRP [mg/dL] ×10⁴. Kaplan-Meier and receiver operating characteristic curve analyses were used to evaluate survival outcomes and the predictive performance of the index.

Results: Patients with a CALLY index of ≥1.33 had significantly longer OS (median 62 vs. 29 months, p < 0.001), and a cut-off of ≥1.11 was predictive of improved DFS (p = 0.004). The index demonstrated moderate discriminative ability (AUC: 0.682 for OS; 0.647 for DFS). CRP and albumin were independent prognostic factors, whereas lymphocyte count was not.

Conclusion: The CALLY index may serve as a valuable prognostic tool in patients with non-metastatic MIBC undergoing RC. Its incorporation into clinical risk stratification models could enhance individualized treatment planning. Prospective studies are warranted to validate these findings.