Radiation-induced squamous cell carcinoma of the nasopharynx after radiotherapy for nasopharyngeal carcinoma.

Background: The purpose of this study was to investigate the treatment outcome of radiation-induced squamous cell carcinoma (SCC) of the nasopharynx after radiotherapy (RT) for nasopharyngeal carcinoma (NPC).

Methods: We conducted a retrospective review of patients who underwent radiation therapy for NPC, which resulted in radiation-induced SCC of the nasopharynx.

Results: Between 1998 and 2011, 24 patients had radiation-induced SCC of the nasopharynx. The median age of diagnosis was 68.2 years. The majority of patients (66.7%) presented with early-stage NPC initially, and they were treated with RT alone (n = 18) or concurrent chemoradiation (n = 6). The mean latency period for the second malignancy was 10.5 years. All the patients were treated with maxillary-swing nasopharyngectomy. Clear resection margin was achieved in 66.7%, and 75% of those with involved margin received adjuvant RT. The mean follow-up duration was 48.2 months. The overall 5-year actuarial local tumor control was 56% and the overall 5-year disease-free survival was 38%.

Conclusion: Radiation-induced SCC of the nasopharynx is rare after RT for NPC. The prognosis remained poor despite aggressive surgery and adjuvant RT.