Prognostic Factors for Loco-regional Control and Outcome of Re-irradiation for Patients with Poorly-differentiated Squamous Cell Carcinoma of the Nasopharynx

: Retrospective analysis was performed to evaluate the prognostic factors for loco-regional control and the results of re-irradiation for 28 patients with recurrent, poorly-differentiated squamous cell carcinoma (PDSCC) of the nasopharynx. Twenty-four of them received re-irradiation. Local, local plus regional and regional recurrences were observed in 19, five and four patients, respectively. Except for three patients, all had Stage IV disease at the initial diagnosis. The only parameters influencing loco-regional recurrence were T and N stage categories. The median latent period from initial treatment to recurrence was 18.5 (range, 2-100) months. There was no difference in latent period by first recurrence site, although recurrent tumors confined to the nasopharynx or those only regionally developed had a longer latent period. Only four patients developed secondary distant bone metastases with a median latency of three months from loco-regional relapse. The patients with local recurrent tumors confined to the nasopharynx, and those with regional recurrences only, could be salvaged by re-irradiation, with five-year survival rates of 44 and 100%, respectively. Five of 28 patients (18%) developed severe chronic radiation sequelae: cerebrospinal complications in four patients, bilateral neck fibrosis in one. We conclude that recurrent PDSCC of the nasopharynx can be controlled by re-irradiation with some success. Radiation therapy techniques must, however, be carefully planned in order to avoid the severe late post re-irradiation sequelae. For patients with advanced non-curable local recurrences, palliative care should be recommended instead of agressive re-irradiation.