Trends and variations in the use of adjuvant therapy for patients with head and neck cancer.

BACKGROUND: The National Comprehensive Cancer Network guidelines recommend that patients with surgically resected head and neck cancers that have adverse pathologic features should receive adjuvant therapy in the form of radiotherapy (RT) or chemoradiation (CRT). To the authors' knowledge, the current study is the first analysis of temporal trends and use patterns of adjuvant therapy for these patients.
METHODS: Patients with head and neck cancer and adverse pathologic features were identified in the National Cancer Data Base (1998-2011). Data were analyzed using chi-square, Student t, and log-rank tests; multivariate logistic regression; and Cox multivariate regression.
RESULTS: A total of 73,088 patients were identified: 41.5% had received adjuvant RT, 33.5% had received adjuvant CRT, and 25.0% did not receive any adjuvant therapy. From 1998 to 2011, the increase in the use of adjuvant CRT was greatest for patients with oral cavity (6-fold) and laryngeal (5-fold) cancers. Multivariate analysis demonstrated that Medicare/Medicaid insurance (odds ratio [OR], 1.05; 95% confidence interval [95% CI], 1.01-1.11), distance ≥34 miles from the cancer center (OR, 1.66; 95% CI, 1.59-1.74), and academic (OR, 1.26; 95% CI, 1.20-1.31) and high-volume (OR, 1.10; 95% CI, 1.05-1.15) centers were independently associated with patients not receiving adjuvant therapy. Receipt of adjuvant therapy was found to be independently associated with improved overall survival (hazard ratio, 0.84; 95% CI, 0.81-0.86).
CONCLUSIONS: Approximately 25% of patients are not receiving National Comprehensive Cancer Network guideline-directed adjuvant therapy. Patient-level and hospital-level factors are associated with variations in the receipt of adjuvant therapy. Further evaluation of these differences in practice patterns is needed to standardize practice and potentially improve the quality of care. Cancer 2014;120:3353-3360.