Impact of Hospital Procedure Volume on Surgical Operation and Long-Term Outcomes in High-Risk Curatively Resected Rectal Cancer: Findings From the Intergroup 0114 Study

PURPOSE: Prior studies have demonstrated superior outcomes after a curative surgical resection of rectal cancer at hospitals where the volume of such surgeries is high. However, because these studies often lack detailed information on tumor and treatment characteristics as well as cancer recurrence, the true nature of this relation remains uncertain. PATIENTS AND METHODS: We studied a nested cohort of 1,330 patients with stage II and stage III rectal cancer participating in a multicenter, adjuvant chemoradiotherapy trial. We analyzed differences in rates of sphincter-preserving operations, overall survival, and cancer recurrence by hospital surgical volume. RESULTS: We observed a significant difference in the rates of abdominoperineal resections across tertiles of hospital procedure volume (46.3% for patients resected at low-volume, 41.3% at medium-volume, and 31.8% at high-volume hospitals; P <.0001), even after adjustment for tumor distance from the anal verge. However, this higher rate of sphincter-sparing operations at high-volume centers was not accompanied by any increase in recurrence rates. Hospital surgical volume did not predict overall, disease-free, recurrence-free, or local recurrence-free survival. However, among patients who did not complete the planned adjuvant chemoradiotherapy (270 patients), those who underwent surgery at low-volume hospitals had a significant increase in cancer recurrence (adjusted hazard ratio, 1.94; 95% CI, 1.01 to 3.72; P =.04 for the trend) and a nonsignificant trend toward increased overall mortality (P =.08) and local recurrence (P =.10). In contrast, no significant volume-outcome relation was noted among patients who did complete postoperative therapy. CONCLUSION: Using prospectively recorded data, we found that hospital surgical volume had no significant effect on rectal cancer recurrence or survival when patients completed standard adjuvant therapy. Sphincter-preserving surgery was more commonly performed at high-volume centers.