T4-Locally Advanced Nasopharyngeal Carcinoma: Prognostic Influence of Cranial Nerve Involvement in Different Radiotherapy Techniques

Background. Cranial nerve involvement at disease presentation of nasopharyngeal carcinoma was not uncommon. We investigated the prognosis of patients with T4-locally advanced NPC, with or without cranial nerve involvement, and compared the outcome of patients treated using different radiotherapy techniques. Methods. In this retrospective study, 83 T4-locally advanced NPC patients were diagnosed according to the seventh edition of the American Joint Committee on Cancer staging system. All patients were treated using three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiation therapy (IMRT). The survival rate was analyzed using the Kaplan-Meier method. Results. The 5-year overall, locoregional-free, and disease-free survival rates of patients treated using IMRT were 88.9%, 75.2%, and 69.2%, respectively. The outcome in these patients was significantly better than that in patients treated using 3D-CRT, with survival rates of 58.2%, 54.4%, and 47.2%, respectively. There was no significant difference in the 5-year overall, locoregional-free, and disease-free survival rates of the patients with (64.2%, 60.5%, and 53.5%, resp.) and without (76.9%, 63.6%, and 57.6%, resp.) cranial nerve involvement. Conclusion. Locally advanced NPC patients treated using IMRT had significantly better outcomes than patients treated using 3D-CRT. Our results showed that the outcome of T4 NPC patients with or without cranial nerve involvement was not different.