Nomograms Based on Blood-Based Biomarkers for Predicting Prognosis in Locally Advanced Nasopharyngeal Carcinoma Patients.

Purpose: This study aimed to investigate the prognostic significance of the platelet-to-platelet distribution width ratio (P/PDW), systemic inflammation response index (SIRI), and systemic immune inflammation index (SII) in patients with locally advanced nasopharyngeal carcinoma (LA-NPC). Methods: A total of 549 LA-NPC patients were included in this retrospective analysis. Clinicopathological characteristics and blood test data were obtained from patient records. Receiver operating characteristic (ROC) curve analysis was employed to determine the optimal cutoff values for P/PDW, SIRI, and SII. The χ ² test was used to compare clinicopathological characteristics. Survival rates were calculated using the Kaplan-Meier method. Prognostic factors were evaluated using univariate and multivariate analyses via Cox regression. Additionally, we developed a nomogram to predict outcomes and assessed its acuracy using the concordance index (C-index) and a calibration curve. Results: The median follow-up time was 47.1 months. Elevated P/PDW levels were associated with advanced N stages and higher risks of disease progression (all p  < 0.05). Patients with high SIRI or SII levels were more likely to have advanced T stages, clinical stages, and to develop metastasis (all p  < 0.05). Univariate analysis revealed that P/PDW, SIRI, SII, and T stage were significantly correlated with both overall survival (OS) and progression-free survival (PFS; all p  < 0.05). Clinical stage was significantly related only to PFS (p=0.009). Multivariate Cox regression analysis identified P/PDW (hazard ratio (HR): 0.544, 95% confidence interval (CI): 0.390-0.759, p  < 0.001; HR: 0.406, 95% CI: 0.268-0.615, p  < 0.001) and T stage (HR: 0.539, 95% CI: 0.378-0.768, p=0.001; HR: 0.545, 95% CI: 0.364-0.815, p=0.003) as independent prognostic factors for both OS and PFS, while SIRI (HR: 0.525, 95% CI: 0.333-0.827, p=0.006) was an independent predictor of OS. Nomogram C-indexes for the nomogram of OS were 0.717 and PFS were 0.711, respectively. Survival predictions and actual survival were consistent according to the calibration curve. Conclusion: Our findings suggest that P/PDW is a convenient and effective marker for predicting outcomes in LA-NPC patients.