Patterns Of Care And Outcomes Of Adjuvant Therapy For High Risk Head And Neck Cancer After Surgery

To analyze the patterns of care and survival for patients undergoing surgery for head and neck cancer and found to have locally advanced disease, positive margins, or extracapsular extension (ECE) The National Cancer Database was explored to identify patients’ ≤70 years old that were diagnosed with head and neck squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx between 2004-2012. Patients were included if they underwent surgery (> local excision) and were staged as pT3-4N0-3, pT1-4N2-3, or any stage with positive margins and/or ECE. Patients were then stratified into receipt of postoperative radiation alone (postopRT) or postoperative chemoradiation (postop chemoRT). Those who received surgery alone, and those who survived <6 months were excluded. Univariable and multivariable logistic regression was used to assess for predictors of chemoradiation. Univariable and multivariable Cox Regression was similarly performed to assess for covariables that had an impact on survival. Propensity matching was performed and the multivariable Cox Regression was repeated utilizing the propensity matched sample. There were 12,224 patients included in this study, from which 4,636 (37.9%) received postop RT and 7,588 (62.1%) received postop chemoRT. Those with positive margins and/or ECE received chemoRT 67.1% of the time and those with negative margins and no ECE received chemoRT 54.0% of the time. On multivariable logistic regression, the strongest predictors for postop chemoRT were ECE (OR 2.21, 95% CI 2.03-2.41, p<0.001) and N2-3 disease (OR 2.27, 95% CI 1.98-2.59, p<0.001), followed by positive margins (OR 1.56, 95% CI 1.42-1.72, p<0.001). The 5 year overall survival was 61.6% for postop RT versus 67.4% for postop chemoRT (p<0.001). On multivariable Cox Regression, postop chemoRT was associated with improved survival (HR 0.87, 95% CI 0.0.82-0.93, p<0.001). Propensity score matching identified a cohort of 5,584 patients in a 1:1 match. Multivariable Cox Regression on the propensity matched sample revealed a persistent improvement in survival associated with postoperative chemoradiation (HR 0.87, 95% CI 0.79-0.96, p=0.006). On subset analysis of the matched sample, there was no longer a survival benefit for those with negative margins and no ECE (p=0.15), but the survival benefit persisted for those with positive margins or ECE (p=0.006). In this large, hospital-based sample, the use of postop chemoRT appeared relatively underutilized (67%) for patients with positive margins or ECE and over utilized (54%) for patients with negative margins and no ECE. On the propensity matched cohort, postop chemoRT was associated with improved overall survival for those with positive margins or ECE only.