C-reactive protein-albumin-lymphocyte index and survival outcomes in renal cell carcinoma: a systematic review and meta-analysis

Background The C-reactive protein-albumin-lymphocyte (CALLY) index is a composite biomarker integrating systemic inflammation, nutritional status, and immune competence. Although its prognostic value has been investigated in several malignancies, its clinical relevance in renal cell carcinoma (RCC) remains incompletely defined. We conducted a systematic review and meta-analysis to evaluate the association between the CALLY index and survival outcomes in patients with RCC. Methods PubMed and Embase were systematically searched from database inception to August 2026 for cohort studies evaluating the prognostic value of the CALLY index in RCC. Hazard ratios (HRs) and 95% confidence intervals (CIs) for progression-free survival (PFS) and overall survival (OS) were extracted and pooled using random-effects models. Subgroup analyses were performed according to the clinical populations represented by localized/clear cell RCC (ccRCC) and metastatic/mixed-histology RCC. Results Five retrospective cohort studies comprising 587 patients were included. Across clinically heterogeneous RCC populations, a low CALLY index was associated with worse PFS (pooled HR = 2.89, 95% CI: 1.82–4.58; I² = 24.7%) and OS (pooled HR = 2.32, 95% CI: 1.61–3.35; I² = 0%). The 95% prediction interval included the null value for PFS (0.84–9.98) but not for OS (1.30–4.17). Subgroup analyses comparing localized/ccRCC with metastatic/mixed-histology populations did not identify statistically significant differences between subgroups for PFS or OS. Conclusion A low CALLY index was associated with poorer PFS and OS across the heterogeneous RCC populations represented in the available retrospective studies. These findings support the potential role of CALLY as an adjunctive prognostic biomarker but do not establish stage-specific or treatment-specific effects. Prospective multicenter studies using standardized measurement protocols and externally validated cut-offs are needed to determine its incremental prognostic value and clinical utility. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420261484115 , identifier CRD420261484115.