Distal Spread of Rectal Cancer and Optimal Distal Margin of Resection for Sphincter-preserving Surgery

Background: Ascertaining the optimal distal margin of resection in sphincter-preserving surgery has become an important problem. This study was designed to examine distal rectal spread of rectal carcinoma and to determine the optimal distal margin of resection for sphincter-preserving surgery.

Methods: Six hundred ten consecutive specimens of resected rectal carcinomas were analyzed retrospectively and pathologically.

Results: Sixty-one patients (10%) had distal spread. In patients who underwent curative surgery, distal spread was observed in only 3.8% (19/505). Distal spread was not found in patients with Stage I disease (0/150), according to the International Union Against Cancer stage. Only 1.2% (2/162) of patients with Stage II disease and 5.1% (10/195) with Stage III disease had slight spread but this was confined within a 1 cm length. Most patients with distal spread had a lower survival rate and died of distant metastasis rather than local recurrence, even after curative surgery.

Conclusions: Distal spread seems to be an important risk factor for distant metastasis. Distal margin of resection of 1 cm may be appropriate clearance for most rectal cancers.