Assessment of criteria and clinical significance of circumferential resection margins in esophageal cancer.

OBJECTIVE To assess the clinical significance of circumferential resection margins according to current criteria of the College of American Pathologists (CAP) and the Royal College of Pathology (RCP) in esophageal and esophagogastric cancer. DESIGN Prospective study. SETTING Single-surgeon database. PATIENTS One hundred thirty-five patients (mean age, 64 years) with T3 tumors who underwent esophageal resection for cancer between 1991 and 2006. Main Outcome Measure Resection margins criteria and survival. RESULTS Three hundred seventy-four consecutive patients were prospectively identified from an institutional review board-approved database between 1991 and 2006. All patients with T3 tumors (n = 135) had their original pathologic slides reassessed by a single gastrointestinal pathologist. Operative mortality was 0.7% and mean follow-up was 3.1 years. Follow-up was complete in 81% of patients. Positive margins were identified in 16 cases in the CAP group vs 83 cases in the RCP group. Five-year Kaplan-Meier survival curves in the CAP group demonstrated a significant (P < .001) difference in survival, whereas the RCP group showed no difference (P = .20). In comparisons of negative vs positive margins, respectively, median survival in the CAP group (29.8 months [95% confidence interval (CI), 22.7-36.9] vs 8.33 months [95% CI, 4.4-12.3]) was significantly different from the RCP group (28.47 months [95% CI, 19.7-37.2] vs 22.23 months [95% CI, 13.6-30.8]). At 60-month follow-up, the positive predictive value with respect to survival was 100% in the CAP group vs 81% in the RCP group. Univariate and multivariate analyses identified R1 margins in the CAP group and lymph node ratio as being directly linked to survival. CONCLUSIONS Positive circumferential resection margins are prognostically important and the CAP criteria provide a more clinically meaningful assessment. Universal adoption of the CAP system can improve interpretation of international clinical trials and allow more accurate comparisons of outcomes.