Impact of treating facilities' type and volume in patients with major salivary gland cancer.

OBJECTIVES/HYPOTHESIS: Investigate the relationship between facility volume and type on overall survival (OS) in patients with major salivary gland cancer undergoing surgical treatment.

STUDY DESIGN

Retrospective review of the National Cancer Database (NCDB) 2004-2015.

METHODS

The NCDB was queried for patients with surgically treated major salivary gland cancer. The mean number of cases treated at each institution was calculated. High-volume facilities (HVFs) were defined as the top 10% of centers. Univariate and multivariate propensity score-matched analyses were performed to evaluate the impact of facility volume and type on OS.

RESULTS

A total of 8,658 patients were analyzed. Distribution among facilities was highly skewed, with a median value of 1.38 cases/year (range, 0.11-23.25). On univariate analysis, treatment at HVFs was not associated with improved OS. However, there were significantly more patients with adverse clinical features treated at HVFs. Treatment at HVFs was associated with increased rates of concomitant neck dissections and lower rates of positive margins. In propensity-score matched cohorts, OS was not significantly improved in patients treated at HVFs (hazard ratio [HR]: 0.979; 95% confidence interval [CI]: 0.879-1.091) or academic/research institutions (HR: 0.914; 95% CI: 0.821-1.018).

CONCLUSIONS

Regionalization of care is occurring in patients with major salivary gland malignancies. Patients treated at HVFs had greater rates of adverse clinical features and more commonly underwent neck dissections, although adjuvant radiotherapy rates were similar between facility types. There was no apparent survival benefit to patients treated at HVFs or academic/research institutions, although there were lower rates of positive margins at HVF.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:2321-2327, 2019.