Radiotherapy for Nasopharyngeal Carcinoma

Lee, Myung Za; Chun, Ha Chung

Abstract

PURPOSE: To evaluate the results of radiation management on recurrence, survival and prognostic factors of patients with nasopharyngeal cancer.
MATERIALS AND METHODS
Forty-nine patients, treated for nasopharyngeal cancer by radiotherapy between January 1984 and June 2000, were retrospectively studied. All patients were followed up for at least 2.5 years. Their median age was 52 years (range 17~78). The histological types were 21 squamous cell carcinoma, 25 undifferentiated carcinoma, and 3 adenoid cystic carcinoma. The tumor stages were as follows: T1 in 14 patients, T2 in 24, T3 in 3, and T4 in 8, and N0 in 17 patients, N1 in 15, N2 in 4 and N3 in 13. Stages I, IIa, IIb ,III, IV and IVb were 4, 7, 12, 5, 8, and 13 patients respectively. Radiation doses of 58~70 Gy (median 68.7 Gy) were given to the nasopahryngeal and involved lymphatic areas and of 46~50 Gy to the uninvolved neck areas.
RESULTS
The overall 5 and 10-year actuarial and disease free survival rates were 54.53% and 47%, and 55.7% and 45.3%, respectively. The overall five-year survival rates were 100% in stage I , 80% in stage IIa, 59.5% in stage IIIb, 40% in stage III, and 42.2% in stage IV tumors. Twenty-three patients failed either loco-regionally or distantly. Incidences of local failure, regional failure and distant metastasis for the first failure were 20.4%, 8.2% and 20.4%, respectively. Local recurrences were 4.3% in T1, 12.5% in T2, 0% in T3, and 62.5% in T4 lesions. Distant metastasis was seen in 41.2% of N2-3 lesions. Fifty percent of local recurrence appeared within 2 years of treatment at the primary lesion, whereas 70% of distant metastasis appeared within 2 years following treatment. Young age, female, early T stage, N0 stage, and poorly differentiated carcinoma were all related with good survival. However only stage showed statistically significance.
CONCLUSION
Based on the results of this study, radiation therapy to nasopharyngeal cancer showed high local recurrence in T4 and increased metastasis in N2-3 lesions. To improve local failure, further radiation doses, such as stereotactic radiation or IMRT radiation, are necessary especially in T4 lesions. The high incidence of distant metastasis in positive lymph node patients, indicates that combined radiation and effective chemotherapeutic agents with appropriated schedule are necessary.