Secondary Neuroendocrine Carcinoma Following High-Dose Radiotherapy for Head and Neck Cancer: Report of Two Cases

Patients treated with radiation have an increased risk of developing second cancers, of which carcinomas, sarcomas, and hematological malignancies have most commonly been reported. Neuroendocrine carcinomas (NEC) are rarely reported in patients previously treated with radiation. Two patients, who had successfully undergone chemoradiotherapy for head and neck cancers at our institution, developed secondary NEC within the radiation field more than five years after the treatment. Both patients underwent curative-intent treatment of secondary malignancies, one with chemotherapy, radiation and surgery (Case 1) and the other with chemotherapy and surgery (Case 2). Both had no evidence of disease at a short follow-up of twelve months (Case 1), and three months (Case 2) after treatment. NEC can develop post-radiotherapy; a multidisciplinary approach is necessary to successfully treat these patients.