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. © 2013 Wiley Periodicals, Inc. Head Neck 36: 772–775, 2014