Hospital Volume for Rectal Cancer Resection Plays a Pivotal Role in Improving Outcomes

Objective: Assessing the association between hospital surgical volume (SV) and outcomes after rectal cancer surgery (RCS), using national population-based data. Background: For RCS, the association of higher SV with improved short-term and/or long-term outcomes remains controversial. Methods: National Cancer Registry data and administrative data were used to select patients diagnosed with stage I to III rectal cancer in 2009 to 2018 and who underwent RCS. The average annual SV of RCS was categorized as low (<15; LV), medium (15–29; MV), or high (≥30; HV). The association between SV and 90-day and 1-year excess postoperative mortality (90DPM and 1YEPM) and 5-year observed survival (5YOS) was evaluated. Results: From the 11,519 patients, RCS was performed in LV (4088; 36%), MV (2795; 24%), or HV (4636; 40%) hospitals. Observed 90DPM was significantly better in HV (2.3%; 95% CI: 1.9, 2.8) than in LV (3.7%; 95% CI: 3.2, 4.4) and MV (3.5% 95% CI: 2.9, 4.3) with adjusted OR of 1.4 ( P <0.0001). Continuous regression analysis showed significantly higher 90DPM in annual SV<35 compared with ≥35 (OR=1.6; 95% CI: 1.21, 2.11; P =0.0009). Observed 1YEPM was significantly better in HV (2.9%; 95% CI: 2.2, 3.6) compared to LV (4.7%; 95% CI: 3.9, 5.6) with adjusted excess HR of 1.31 (95% CI: 1.00, 1.73) and P =0.05, and to MV (5.0%; 95% CI: 4.0, 6.1) with adjusted excess HR of 1.45 (95% CI: 1.09, 1.94) and P =0.01. The 5YOS was significantly better in HV (75.9%; 95% CI: 74.6, 77.2) than in LV (70.3%; 95% CI: 68.8, 71.8) and MV (71.5%; 95% CI: 69.7, 73.2) with adjusted HR of 1.4 in both LV and MV versus HV ( P ≤0.003). Conclusion: This population-based study identified robustly superior outcomes at 90 days, 1 year, and 5 years after RCS in hospitals with higher volumes.