Adjuvant radiotherapy and survival for patients with node-positive head and neck cancer: an analysis by primary site and nodal stage.
OBJECTIVE
Adjuvant radiotherapy (RT) is frequently recommended for node-positive head and neck squamous cell carcinoma (HNSCC) treated with primary surgery. The impact of RT on survival for various subgroups of node-positive HNSCC has not been clearly demonstrated.


METHODS
Within the Surveillance, Epidemiology, and End Results (SEER) Database, we identified 5297 patients with node-positive (N1 to N3) HNSCC treated with definitive surgery with or without adjuvant RT between 1988 and 2001. The median follow-up was 4.4 years.


RESULTS
Adjuvant RT significantly improved 5-year overall survival (46.3%: 95% confidence interval [CI], 44.7-48.0% for surgery + RT, vs. 35.2%: 95% CI, 32.0-38.5% for surgery alone, p < 0.001) and cancer-specific survival (54.8%: 95% CI, 53.2-56.4% for surgery + RT, vs. 46.2% for surgery alone 95% CI, 42.4-50.0%, p < 0.05). Use of adjuvant RT remained a significant predictor of survival on multivariable analysis (hazard ratio [HR], 0.75; 95% CI, 0.68-0.83; p < 0.001). Subset analyses demonstrated that adjuvant RT was associated with significantly improved survival for N1 (HR, 0.78; 95% CI; 0.67-0.90; p = 0.001), N2a (HR, 0.82; 95% CI, 0.67-0.99, p = 0.048) and N2b to N3 nodal disease (HR, 0.62; 95% CI, 0.51-0.75; p < 0.001). Adjuvant RT increased overall survival for node-positive patients with oropharynx (HR, 0.72; 95% CI, 0.57-0.90; p = 0.004), hypopharynx (HR, 0.66; 95% CI, 0.49 to 0.88; p = 0.004), larynx (HR, 0.66; 95% CI, 0.52-0.84; p = 0.001), and oral cavity (HR, 0.84; 95% CI, 0.73-0.98; p = 0.025) primary tumors.


CONCLUSIONS
In a large population-based analysis, adjuvant RT significantly improves overall survival for patients with node-positive HNSCC. All nodal stages, including N1, appear to benefit from the addition of RT to definitive surgery.
Kao
Johnny
J
Department of Radiation Oncology, Mount Sinai School of Medicine, New York, NY 10029, USA. johnny.kao@mountsinai.org
Lavaf
Amir
A
Teng
Marita S
MS
Huang
Delphine
D
Genden
Eric M
EM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002294:Carcinoma, Squamous Cell / Q000401:mortality* / Q000532:radiotherapy* / Q000556:secondary / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006258:Head and Neck Neoplasms / Q000401:mortality* / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D018714:Radiotherapy, Adjuvant; D018426:SEER Program