M. R. Ju1, G. Leonard1, S. C. Wang1, P. M. Polanco1, J. C. Mansour1, A. C. Yopp1, H. J. Zeh1, S. Reznik1, M. R. Porembka1 1University Of Texas Southwestern Medical Center, Surgery, Dallas, TX, USA
Introduction:
Performance of major lung resections at high-volume (HV) hospitals has been shown to reduce operative mortality. However, what threshold of case volume meaningfully impacts surgical outcomes is unknown. We determined a clinically meaningful cut-point for defining HV centers for major lung resections and assessed the impact of hospital volume on surgical outcomes and overall survival.
Methods:
We identified adult NCDB patients with SCLC/NSCLC undergoing lobectomy or pneumonectomy between 2004-2015. A multivariable model with restricted cubic splines was built to predict 5-year overall survival according to average yearly case volume, adjusting for demographic/clinicopathologic factors. This data was then analyzed using a change-point procedure which identified two regression lines and a distinct segmentation at 54 cases/year. Hospitals were subsequently divided into HV (>/=54 cases/year) and low-volume (LV, <54 cases/year) groups. Chi-square tests were used to analyze group differences. Logistic regression was utilized to assess the impact of hospital volume on surgical outcomes. Overall survival was estimated using the Kaplan-Meier method and compared using log-rank tests.
Results:
Our cohort consisted of 284,138 patients (31.5% treated at HV centers). Treatment at a HV center was associated with increased likelihood of R0 resection (OR 1.40, 95% CI 1.35-1.46). Patients treated at HV centers were also significantly more likely to have an adequate lymph node evaluation of 10 or more nodes (OR 1.71, 95% CI 1.68-1.74). HV centers also had significantly decreased 30- and 90-day postoperative mortality (OR 0.76, 95% CI 0.72-0.80 and OR 0.81, 95% CI 0.78-0.84; respectively) after adjusting for age, sex, race, comorbidities, histology, surgery type, and stage. Stage-specific overall survival was significantly improved at HV vs LV centers.
Conclusion:
Treatment at a HV center is associated with significantly improved oncologic and surgical outcomes. The performance of 54 major lung resections a year is a clinically meaningful cutoff to differentiate HV and LV centers. This should be considered when evaluating regionalization of lung cancer care to improve patient outcomes.