Is the circumferential resection margin a predictor of local recurrence after preoperative radiotherapy and optimal surgery for rectal carcinoma?

OBJECTIVE: Circumferential resection margin (CRM) involvement has been correlated with a high risk of developing local recurrence. The aim of this study was to examine the prognostic significance of the CRM involvement after curative resection of rectal cancer in patients treated with preoperative radiotherapy and postoperative chemotherapy where indicated. METHOD: All patients with rectal cancer treated in a regional central unit from 1996 to 2004 were identified. A surgical resection was performed on 257 patients, and in 229 of these this was assessed as potentially curative. The CRM was examined in all patients. A CRM of < or = 1 mm was considered positive. RESULTS: A positive margin was seen in 19 (8%) patients. At a median follow up of 40 months, only four (1.7%) patients had developed local recurrence, one of whom had a positive CRM. In the four patients the tumour was 5 cm or less from the anal verge. There were no significant differences regarding local recurrence and survival between CRM positive and negative tumours. CONCLUSION: Rectal cancer managed by combined radiochemotherapy and surgery resulted in a low positive CRM rate and a low local recurrence rate. An involved CRM was not a predictor of local recurrence.