An Analysis of Prognostic Factors Affecting the Outcome of Radiation Therapy for Nasopharyngeal Carcinoma / 대한방사선종양학회지

ABSTRACT

PURPOSE: This retrospective study was conducted to analyze the treatment results and to evaluate the prognostic factors affecting the survival of nasopharyngeal carcinoma patients. MATERIALS AND METHODS: From 1987 to 2002, we analyzed 43 patients who had nasopharyngeal carcinomas that were histologically confirmed and who had also completed the planned radiation therapy course at Keimyung University Dongsan Medical Center. According to the 6th edition of American Joint Committee on Cancer staging system, 12 patients (27.9%) were at Stage II, 13 (30.2%) were at Stage III and 18 (41.9%) were at Stage IV. Histopathologically, there were 15 (34.9%) squamous cell carcinomas, 8 (18.6%) nonkeratinizing carcinomas, 17 (39.5%) undifferentiated carcinomas, and 3 (7.0%) lymphoepitheliomas. Among the total 43 patients, 31 patients (72.1%) were treated with only radiation therapy. Neoadjuvant chemotherapy was performed on 7 patients (16.3%) and concurrent chemoradiotherapy was performed on 5 patients (11.6%). Cisplatin and 5-Fluorouracil were administered to 11 patients for 4 cycles, and Cisplatin and Taxotere were administered to 1 patient for 6 cycles. The range of the total radiation dose delivered to the primary tumor was from 61.2 to 84 Gy (median 70.4 Gy). The follow-up period ranged from 2 to 197 months with median follow-up of 84 months. RESULTS: The local control rate at 6 months after radiation therapy was 90.7%. The five year overall survival and disease free survival rates were 50.7% and 48.9%, respectively. On the multivariate analysis, the age, T-stage (T1-3 vs T4), N-stage and AJCC stage were the statistically significant prognostic factors affecting survival (p<0.05). The patterns of failure were as follows: local failure only in 3 patients (7.0%), local and systemic failure in 1 patient (2.3%), and distant metastasis only in 11 patients (25.6%). CONCLUSION: The prognostic factors affecting the outcome of nasopharyngeal carcinoma were age, T-stage (T1-3 vs T4), N-stage and stage. Because systemic metastasis was the main failure pattern noted for nasopharyngeal carcinoma, systemic chemotherapy is needed to decrease the rate of distant metastasis for nasopharyngeal carcinoma. In addition, research for more effective chemotherapeutical regimens and schedules is also needed.