The prognostic significance of circumferential resection margin involvement in colon cancer

Objective: Failure patterns after colon cancer surgery demonstrated that tumors localized at non-peritonealized part of the colon and sited adjacent to anatomically narrow mesentery were responsible for locoregional recurrent disease and reduced survival. The aim of this study was to assess the prognostic significance of circumferential resection margin(CRM) involvement in patients who underwent potentially curative resection for colonic cancer.Material and Methods: Between January 2005 and January 2008, 179 patients who underwent curative radical resection for colon carcinoma(pT3-pT4) in Dokuz Eylül University School of Medicine, Department of Surgery, Division of Colorectal Surgery were evaluated for clinicopathologic data and final oncologic outcomes prospectively. In histopathological assessment, CRM represents the retroperitoneal or peritoneal adventitial soft tissue margin closest to the deepest penetration of tumor.Results: CRM was involved in 25(%14) patients. There were was significant associations between CRM involvement and tumor diferentiation, tumor invasion depth, lymph node involvement, venous invasion lymphatic vesssel invasion, type of tumor invasion border, and local recurrence (p<0.05). Significant relation was observed between CRM and venous invasion positivity and tumor invasion depth in multivariate analysis(p<0.05). Compared with CRM negative tumors, CRM positive tumors were associated with increased local recurrence(p<0.01). Median disease free survival was 355±74 days for patients with CRM involvement whileas, 609±45 days for patients without CRM involvement(p<0.05). CRM involvement has 0.5 times negative effect on disease free survival(p=0.027; CI=0.276-0.926).Conclusion: CRM involvement in colon carcinoma was determined as indicator of advanced tumor spread. The CRM status was an important predictor of local and distant recurrence as well as survival. Patients with CRM involvement may benefit from postoperative chemotherapy and/or radiotherapy. It should be routine to comment on this prognostic factor in histopathology reports of resected colonic specimens.