Diagnostic value of C-reactive protein-albumin-lymphocyte index in breast cancer cases

The most frequently diagnosed malignancy among women worldwide is breast cancer. Inflammation, nutritional status, and immune competence are increasingly recognized as major determinants of tumor progression and prognosis in cancer cases. The C-reactive protein-albumin-lymphocyte (CALLY) index, a composite biomarker reflecting these parameters, has shown promise in studies of various tumors. However, research on the CALLY index in breast cancer remains limited in the literature.

In this study, we evaluated the diagnostic significance and staging performance of the CALLY index in patients with breast carcinoma.

A total of 303 female patients diagnosed with breast cancer between November 2018 and December 2024 were retrospectively analyzed. Pre-treatment serum CRP, albumin, and lymphocyte counts were used to calculate the CALLY index (Albumin [g/dL] × Lymphocyte count [/µL])/(CRP [mg/dL] × 10⁴⁾. Patients were classified into early-stage (Stage I-II) and advanced-stage (Stage III-IV) groups. Group comparisons were performed using Mann-Whitney U and Kruskal-Wallis tests. ROC analysis and supervised machine learning algorithms were used to evaluate the discriminative performance of the CALLY index and CA-15-3.

The mean CALLY index was significantly higher in early-stage patients compared to those with advanced-stage disease (p < 0.001). The index demonstrated excellent discriminative ability for staging, with an optimal cut-off value of 0.693 (AUC: 1.00; sensitivity: 100%; specificity: 100%). In multivariate analysis, the CALLY index outperformed CA 15-3 in predicting tumor stage. Machine learning classification confirmed that the CALLY index was the most important variable for stage prediction, and the neural network model achieved an accuracy of 84.9% on the test set.

The CALLY index is one of the non-invasive and easily accessible biomarkers that can distinguish between early and advanced breast cancer by integrating inflammatory, nutrition and immune parameters. Furthermore, the CALLY index holds significant potential for pre-treatment prognostic stratification of breast cancer in clinical practice.