Consolidative Radiotherapy After Gemcitabine-Platinum Chemotherapy in De Novo Metastatic Nasopharyngeal Carcinoma: Impact of Chemotherapy Backbone and Prognostic Factors on Survival.

INTRODUCTION

De novo metastatic nasopharyngeal carcinoma (NPC) has a poor prognosis despite modern chemotherapy. Gemcitabine-cisplatin is the standard chemotherapy backbone, whereas carboplatin is commonly used as a cisplatin alternative for its better tolerability. This study evaluated high-dose locoregional radiotherapy (LRRT) after standardized gemcitabine-platinum chemotherapy and identified prognostic factors for patient selection.

METHODS

This retrospective study included patients with de novo metastatic NPC treated at two Hong Kong tertiary centers (2014-2024) with first-line gemcitabine-platinum chemotherapy followed by high-dose LRRT (≥60 Gy). Baseline characteristics, treatment details, toxicities, and outcomes were collected. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method, and prognostic factors were evaluated with log-rank tests and multivariable Cox regression.

RESULTS

Sixty-six patients were included (median age 58 years; 83.3% male). At diagnosis, 27.3% had liver metastases and 83.8% had >1 metastatic lesion. Most (81.8%) completed six chemotherapy cycles (56.1% gemcitabine-cisplatin; 42.4% gemcitabine-carboplatin). LRRT completion rate was 93.9%. The rates of grade 3 dermatitis and mucositis were 18.2% and 7.6%. Two treatment-related deaths were recorded. At a median follow-up of 42 months, median PFS and OS were 6.8 and 22.3 months, respectively; distant progression was the predominant failure pattern (71.2%). On multivariable analysis, liver metastasis and gemcitabine-carboplatin use independently predicted poorer PFS, while gemcitabine-carboplatin and >1 metastatic lesion portended poorer OS.

CONCLUSION

High-dose LRRT after gemcitabine-platinum was feasible with acceptable toxicity but yielded modest PFS in an unselected population of de novo metastatic NPC, with outcomes strongly influenced by metastatic burden, liver involvement, and platinum choice. Gemcitabine-cisplatin remains the preferred chemotherapy backbone, and LRRT may be best reserved for carefully selected patients in the contemporary chemo-immunotherapy era.