A nomogram integrating clinical stage and pre-EBV DNA to identify the cycles of induction chemotherapy for locoregionally advanced nasopharyngeal carcinoma.

Objective: This research focused on determining the optimal cycles of induction chemotherapy (IC) in high-risk locoregionally advanced nasopharyngeal carcinoma (LA-NPC).

Methods: The retrospective analysis was conducted on 885 patients. Potential bias was minimized by propensity score matching (PSM). Overall survival (OS) served as the primary endpoint. Survival outcomes were analyzed using Kaplan-Meier curves, with statistical comparisons performed via the log-rank test. Prognostic determinants were identified through multivariate cox regression analysis. A nomogram model was constructed to quantify individualized prognosis.

Results: Patients were divided into 2/3-cycle (IC = 2/3) and 4-cycle IC (IC = 4) groups. After PSM, 446 patients remained and were categorized into distinct risk groups according to independent predictors, including clinical stage and pre-treatment Epstein-Barr virus DNA (pre-EBV DNA). For the high-risk cohort (stage IVa with pre-EBV DNA ≥ 4000 copies/mL), the IC = 4 regimen showed higher 5-year OS (70.4% vs. 54.7%, P = 0.036) than the IC = 2/3 regimen. In the low- and middle-risk cohorts, the IC = 2/3 regimen exhibited OS comparable to the IC = 4 regimen. The established nomogram model demonstrated superior prognostic power compared to individual factors. Given the adverse effects, the IC = 4 regimen was associated with significantly higher rates of grade 3-4 neutropenia (24.6% vs. 15.5%, P = 0.017) and thrombocytopenia (8.0% vs. 3.7%, P = 0.049) compared to the IC = 2/3 regimen.

Conclusion: The developed nomogram offers personalized guidance on selecting individual IC cycles for LA-NPC patients.