C-reactive protein-albumin-lymphocyte index predicts biochemical recurrence in prostate cancer.

INTRODUCTION

Systemic inflammation and nutritional status influence prostate cancer outcomes. The C-reactive protein-albumin-lymphocyte (CALLY) index integrates these parameters, but its ability to predict biochemical recurrence (BCR) is not well-established.

METHODS

In a single-center, retrospective cohort of 600 patients (2018-2022), the pretreatment CALLY index was calculated as (albumin [g/dL] × lymphocytes [cells/μL])/(CRP [mg/dL] × 104]. Patients were stratified by D'Amico risk. BCR was defined as prostate-specific antigen (PSA) ≥0.2 ng/mL after radical prostatectomy (confirmed) or ≥2.0 ng/mL above nadir after radiotherapy. Kaplan-Meier and Cox models evaluated associations; model performance was assessed using receiver operating curve (ROC), C-index, net reclassification improvement (NRI), and decision-curve analysis (DCA).

RESULTS

Over a median followup of 28.4 months, 26.8% developed BCR. The optimal CALLY threshold was 1524.2, demonstrating modest discriminative ability (area under the curve [AUC] 0.684, 95% confidence interval [CI] 0.624-0.744; sensitivity 72.4%, specificity 64.8%). Low CALLY was associated with higher 36-month BCR rates (31.4% vs. 21.6%; log-rank p=0.042). In multivariable analysis, CALLY independently predicted BCR both as a continuous measure (per 100-unit increase: hazard ratio [HR] 0.882, 95% CI 0.778-0.998, p=0.048) and dichotomized at the median (HR 0.798, 95% CI 0.642-0.992, p=0.042), alongside baseline PSA and Gleason ≥4+4. Adding CALLY modestly improved discrimination of CAPRA (C-index 0.71-0.74) and Memorial Sloan Kettering Cancer Center (MSKCC) (0.73-0.76) models, with NRI 0.246 (p=0.006) and net clinical benefit on DCA across 10-40% thresholds. Effects were most pronounced in high-risk and surgically treated patients.

CONCLUSIONS

The pre-treatment CALLY index represents a readily available biomarker that independently predicts BCR and may complement established risk-stratification tools in prostate cancer, although model performance was modest. External validation in prospective cohorts with longer followup is necessary before clinical implementation.