Purpose: Failure pattern 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.
Methods: Prospectively collected clinicopathological data of 107 patients (T3-T4 tumors) who underwent curative radical resection were analyzed. The CRM represents the retroperitoneal or peritoneal adventitial soft tissue margin closest to the deepest penetration of tumor.
Results: CRM was not involved in 96 patients and involved in 11 patients. There was a significant association between CRM involvement and lymphatic vessel invasion, lymph node positivity, number of involved lymph nodes, and overall TNM stage (p<0.01). Number of involved lymph nodes and overall TNM stage were independent predictors of clinical outcome. CRM positive tumors were associated with increased local recurrence and distant metastasis (p<0.01). The median survival for patients with CRM involvement was only 13 months compared to 20 months without CRM involvement. CRM status had a significant prognostic value in T4 tumors (Figure 1).
Conclusion: The CRM involvement in the colon can be considered to be representative of advanced tumor spread. The CRM status is an important predictor of local and distant recurrence as well as survival. Patients with CRM involvement may benefit from adjuvant treatment. It should be routine to comment on this prognostic factor in histopathology reports of resected colonic specimens.