Impact of Facility Head and Neck Cancer Resection Volume On Positive Margin Rate

Presentation: AHNS065
Topic: Quality of Care and Clinical Pathways
Type: Oral
Date: Thursday, April 19, 2018
Session: 3:30 PM - 4:30 PM Quality Engineering and Pathways
Authors: Cheryl C Nocon, MD1, Gaurav S Ajmani, MHS2, Mihir K Bhayani, MD1
Institution(s): 1NorthShore University HealthSystem, 2University of Chicago Pritzker School of Medicine

Background: The achievement of complete tumor resection and clear tumor-free margins is one of the main principles of oncologic surgery for head and neck squamous cell carcinoma (HNSCC). The negative prognostic impact of a positive margin (PM) across all head and neck subsites has been well-established.

Objective: Our aim was to determine the incidence of PMs in HNSCC across multiple subsites and the factors associated with their occurrence. We hypothesized that margin status is associated with treating facility factors, a potentially modifiable factor in HNSCC treatment that could impact patient outcomes.

Methods: Using the National Cancer Database, we identified patients with clinical stage I-IVb HNSCC, excluding T4b tumors, diagnosed 2010-2014 and treated with definitive surgery. Univariable analysis was conducted using chi-square tests to compare PM rates between demographic, clinical, and facility factors. Multivariable analysis of predictors of PM was performed using a generalized estimating equation (GEE) model adjusting for the same factors, to estimate odds ratios (ORs) per 10-year increase in annual case volume. An interaction between facility volume and facility type was added to assess whether the volume-outcome relationship differed according to type of facility. Finally, a GEE model was used to estimate impact of facility volume in receipt of adjuvant chemoradiation (CRT) among patients with PM.

Results: We identified 28,840 patients with an overall PM rate of 17.6% and average age of 62.4 years (range 40-90+ years). The most common primary site was the oral cavity (53.7%). In univariable analysis, a lower PM rate was associated with higher facility volume (26.3% for the lowest volume quartile; 16.5% for the middle two quartiles; and 10.8% for the highest volume quartile) (P<.001), and treatment at academic centers versus non-academic centers (14.0% vs. 22.7%; P<.001). In multivariable analysis, those treated at lower-volume facilities remained significantly more likely to have PM (OR 0.85; P<.001). The trend of decreasing PM rate with increasing facility volume was observed in both academic and non-academic facilities (OR 0.88 and 0.76, respectively; both P<.001). There was no association between facility volume and patient likelihood of receiving adjuvant CRT in the setting of PM (OR 0.96; P=.071).

Conclusions: Higher volume facilities have lower rates of positive margins in the surgical treatment of HNSCC in both the academic and non-academic settings. Facility volume for head and neck oncologic surgeries may be considered a benchmark for quality of care. Further evaluation of hospital and surgeon factors that are associated with positive margins is warranted.