[Prognostic factors in nasopharyngeal carcinoma in childhood and adolescence].

OBJECTIVE

To analyze the prognostic factors affecting long-term result in pediatric or adolescent nasopharyngeal carcinoma.

METHODS

From January 1984 to December 1998, 117 cases of pediatric and adolescent nasopharyngeal carcinoma proven by pathology were treated by radiotherapy and/or chemotherapy. Their data were retrospectively analyzed. Of the 117 patients, 35 received chemotherapy before radiotherapy, 36 were treated with continuous radiotherapy and the other 81 with split-course radiotherapy. A dose of 56 - 80 Gy/6 - 13 weeks (66.32 +/- 4.72 Gy) was given in the nasopharynx and 47 - 73 Gy/5 - 13 weeks (57.90 +/- 5.80 Gy) in the neck. The survival rates were assessed by Kaplan-Meier analysis and the survival curves compared by Log-rank test. The multivariate analysis was conducted by Cox model.

RESULTS

The 1-, 3- and 5-year overall survival rate was 86.3%, 66.6% and 56.4%, respectively; and disease-free survival rate at 1, 3 and 5 years was 71.8%, 53.9% and 50.4%, respectively. A monovariate analysis showed that the age (P = 0.0015), mode of biopsy (P = 0.0234), N stage (P = 0.0001), mode of irradiation (P = 0.0027), chemotherapy (P = 0.0056) and short-term result (P = 0.0000) were the significant prognostic factors. The multivariate analysis demonstrated that the age (P = 0.027), N stage (P = 0.048), mode of irradiation (P = 0.009) and short-term result (P = 0.000) were the factors influencing prognosis of nasopharyngeal carcinoma in childhood and adolescence. Radiation-induced brain injuries were observed in 17 patients including brain stem injury in 1 (0.9%), temporal brain lobes in 3 (2.6%) and cranial nerves in 13 (11.1%).

CONCLUSION

The mode of irradiation, N stage and short-term result are the significantly influencing factors of prognosis in pediatric and adolescent nasopharyngeal carcinoma. Radiation-induced brain injuries during radiotherapy should not be overlooked.