Background. Circumferential resection margins (CRM) for esophageal cancer (EC), defined by the College of American Pathologists (CAP; >0 mm) or the Royal College of Pathologists (RCP; >1 mm) as tumor-free (R0), are based on a surgery-alone approach. We evaluated the usefulness of both definitions in current practice with neoadjuvant chemoradiotherapy (nCRT).
Methods. CRMs were measured in 209 patients (104 with nCRT) with locally advanced EC after transthoracic esophagectomy. Local recurrence and cancer related death were scored as events. Patients were followed for at least 2 years or until death. Prognostic factors (P <0.1 in univariate analyses) for 2-year disease-free survival (DFS) and local recurrence-free survival (LRFS) were incorporated in multivariate Cox regression analyses. Both CRM measurements were analyzed separately and prognostic cutoff values (0-1.0 mm) were assessed in both groups.
Results. Independent prognostic factors (P <0.05) for 2-year DFS were tumor length, lymph node ratio, angioinvasion, and CAP R0 in the surgery-alone group and pN stage (P <0.01) in the nCRT group. Prognostic factors (P <0.05) for 2-year LRFS were CAP, lymph node ratio, and tumor length in the surgery-alone group, and CAP and grade in the nCRT group. Optimal CRM cutoff values between 0.0 and 0.2 mm were prognostic for 2-year DFS in the surgery-alone and at 0.3 mm for the nCRT group.
Conclusions. nCRT affected the CRM cutoff values. After nCRT, the CRM R0 according to the CAP was only prognostic for 2-year LRFS. However, in the surgery-alone group, it was prognostic for both the 2-year DFS and LRFS.