Prognostic value of the circumferential resection margin after neoadjuvant treatment in esophageal cancer patients.

Abstract

147 Background: Involvement of the circumferential margin (CRM) is an important factor in esophageal cancer (EC) patients. CRM definitions are commonly based on the College of American Pathologists (CAP) at 0 mm and the Royal College of Pathologists (RCP) at >1 mm. We evaluated which CRM definition is useful in current practice with neoadjuvant chemoradiotherapy (CRT) and whether the CRM cut-off value differs after CRT. Methods: We prospectively included 209 patients (104 with CRT) with locally advanced EC (stage II-III), who underwent radical transthoracic esophagectomy. Patients were followed for at least 2 years after surgery or until death. Patients with <1 mm longitudinal resection margins were excluded. Cancer related death was scored as event and death of other causes as end of follow-up (median 27: IQR 14.0 - 42.8 months). CRMs were measured in tenths of millimetres by experienced pathologists. Pathologic proven tumor regrowth, unequivocal radiologic suspicion or obvious clinical manifestations were marked as recurrence. Prognostic factors with a P<0.1 in univariate analyses were incorporated in multivariate Cox-regression analyses in which both CRM definitions were assessed separately. In an explorative analyses the CRM cut-off values in the surgery-only and CRT group for 2-year disease free survival (DFS) was assessed using CRM between 0-1.5 mm in the Cox-regression model. Results: Independent prognostic factors for 2-year DFS (P<0.05) in the study group were: tumor length (>5cm), >0.2 L/N+ ratio, angioinvasion and CAP R0. In the surgery group; tumor length, >4 N+, angioinvasion and CAP R0 were independent prognostic factors (P <0.05). In the CRT group only pN stage (P<0.01) was independent prognostic for 2-year DFS. The CRM cut-off value was significant at 0.2-0.3 mm for the surgery and CRT group, respectively. Conclusions: The CAP value was only independent prognostic for 2-year DFS in the surgery group. The CRM cut-off value was significant at 0.2 and 0.3 mm in the surgery and CRT group, respectively.