Abstract
BACKGROUND: Hospital operative volume has been shown to impact outcomes in complex oncologic surgeries. However, the effect of hospital volume on surgical quality and survival in patients with T4 rectal cancer following neoadjuvant chemoradiation, including total neoadjuvant therapy (TNT), remains unclear. This study evaluates the relationship between hospital volume and the achievement of optimal surgical resection (OSR) in patients with T4 rectal cancer and its subsequent impact on postoperative outcomes and survival. METHODS: A retrospective cohort study was conducted using the National Cancer Database (NCDB) from 2004 to 2021. Patients with T4 rectal cancer undergoing curative-intent oncologic resection following neoadjuvant chemoradiation were included. Hospitals were categorized into low-, medium-, and high-volume tertiles based on the number of T4 rectal cancer resections performed over the study period. The primary outcome was OSR, defined as negative surgical margins and adequate lymph node yield. Multivariable logistic regression and Cox proportional hazards models were used to evaluate factors associated with OSR and survival. RESULTS: A total of 4914 patients from 916 hospitals were analyzed. OSR rates were significantly higher in high-volume hospitals (66.0%) compared to medium- (59.3%) and low-volume hospitals (52.4%) (p < 0.001). On multivariable analysis, treatment at medium- (OR 1.26, 95% CI 1.09-1.45) and high-volume hospitals (OR 1.59, 95% CI 1.37-1.84) independently increased the odds of OSR. Failure to achieve OSR was associated with increased 90-day mortality (OR 2.06, 95% CI 1.16-3.64). Additionally, treatment at low- (HR 1.24, 95% CI 1.09-1.41) and medium-volume hospitals (HR 1.21, 95% CI 1.06-1.38) was associated with higher mortality risk compared to high-volume hospitals. CONCLUSION: Higher hospital operative volume is associated with improved surgical resection quality and survival in patients with T4 rectal cancer following neoadjuvant chemoradiation. These findings support the centralization of complex rectal cancer care to high-volume centers to optimize patient outcomes.