Impact of Surgical and Pathologic Variables in Rectal Cancer: A United States Community and Cooperative Group Report

Abstract

PURPOSE: Substantial and successful effort has been focused on decreasing the risk of local failure after rectal cancer surgery through the use of adjuvant therapies. Our study examined data from studies conducted by United States cooperative groups to investigate the impact of surgical and pathologic variables in rectal cancer outcomes. PATIENTS AND METHODS: Surgical and pathologic reports from 673 patients with stage II/III rectal cancer enrolled onto three adjuvant clinical trials were reviewed for tumor and surgical variables. Additional information on individual institutions and operating surgeon was collected. Variables were tested for association with 5-year local recurrence and survival after adjustment for adjuvant treatments and other important prognostic factors. RESULTS: Five-year local recurrence and survival rates were 16% and 59%, respectively. Surgeons treating more than 10 study cases had lower local recurrence rates than those treating ≤ 10 (11% v 17%, P = .02). Free radial margins also correlated with local recurrence (P = .01). Type of surgery, distal margins, and tumor radial spread were not significant. Tumor adherence to adjacent structures predicted local recurrence (35% v 14%, P < .001) and survival (30% v 63%, P < .001), regardless of en bloc resection. Although T and N classification predicted survival (P < .001), only N classification correlated with local recurrence. The number and percentage of positive nodes correlated with survival, but only the percentage independently predicted local recurrence. Several pathologic and surgical variables were reported suboptimally. CONCLUSION: Moderate variability in outcomes among surgeons was detected in this high-risk population. Efforts to improve surgical results will require changes in reporting practices to allow for more accurate assessment of the quality of surgery.