RISK FACTORS ASSOCIATED WITH RECURRENT DISEASE IN PATIENTS WITH NASOPHARYNGEAL CARCINOMA

A retrospective study was performed, using a univariate method and multivariate analysis, to identify the factors related to locoregional recurrence and distant metastasis in 211 patients with nasopharyngeal carcinoma who were treated with external beam radiation therapy for curative intent between January 1990 and December 1997 at Ankara Oncology Hospital. Patient's age, gender, tumor size (T), lymph node status (N), stage according to TNM classification, histologic type, tumor irradiation dose, lymph node irradiation dose, response to treatment and chemotherapy were used as variables that could be correlated with recurrent disease. Survival curves were calculated by using Kaplan-Meier method. A Cox proportional hazard model was applied to multivariate analysis. The estimated 5-year locoregional recurrence-free and metastasis-free survival were 55% and 79%, respectively. Locoregional recurrence occurred in 95 (46%) of these patients within a mean disease-free period of 18 months. Distant metastasis developed in 44 (21%) patients. The median interval to distant recurrence was 13 months. Although univariate analysis demonstrated that age, gender, T, N, stage, response to treatment were associated with an increased risk of locoregional recurrence (p<0.05), it was found that gender (p=0.0148) and response to treatment (p<0.0001) were statistically significant risk factors when the multivariate analysis was applied. Response to treatment and N were found to be related to distant metastasis by using both univariate and multivariate analyses.

Keywords: nasopharyngeal carcinoma, survival risk factors