A novel scoring model to predict benefit of additional induction chemotherapy to concurrent chemoradiotherapy in stage II-IVa nasopharyngeal carcinoma.

OBJECTIVES

Induction chemotherapy (IC) is gaining recognition for the treatment of nasopharyngeal carcinoma (NPC). We aimed to develop a model to predict benefit from additional IC to concurrent chemoradiotherapy (CCRT).

MATERIALS AND

METHODS

From an NPC-specific database, 7413 patients with stage II-IVa disease who received CCRT with or without IC were included. Distant metastasis-free survival (DMFS) was the primary outcome and benefit from IC was evaluated by adjusted hazard ratio. Interaction terms between IC and other prognostic factors were identified in multivariate Cox model, and IC benefit score (ICBS) was calculated based on β coefficients from the Cox model.

RESULTS

Nodal category, overall stage, and pre-treatment plasma Epstein-Barr virus DNA (log transformed as continuous variable) interacted with IC and determined ICBS. ICBS could discriminate patients who benefited differently from IC in terms of DMFS well, especially for patients with high and low ICBS. As for patients with medium ICBS, predictive performance of ICBS seemed reduced.

CONCLUSIONS

Based on the ICBS model, we proposed a decision-making process to help in clinical practice. Multi-institutional and prospective studies are warranted to further validate our findings.