| Abstract: | PURPOSE In colon cancer surgery, it is recommended that en bloc resection involving extended lymphadenectomy, characterized as a hemicolectomy, be performed by ligating the primary feeding artery at a high position and resecting proximal and distal with 5-cm to 10-cm bowel margins. However, there is little evidence to unequivocally support such extensive lymphovascular resection. METHODS The distribution of nodal metastases was obtained by the clearing method in 164 patients with colon cancer. RESULTS For pericolic spread, for pT1 tumors, the distance from the primary tumor to a diseased node was 2.5 cm; for pT2, the distance was less than 5 cm; for 97.0 percent of pT3 tumors and 93.3 percent of pT4 tumors with nodes involved, the distance was less than 7 cm. For central spread, for pT1 tumors, the rate of spread to central nodes was 0 percent; for pT2, the rate of spread was 20.0 percent to intermediate nodes (for tumors more than 5 cm from the feeding artery, the rate for central nodes was 0 percent); for pT3, the rate was 30.6 percent to intermediate nodes and 15.3 percent to main nodes; for pT4, the rate was 44.4 percent to intermediate nodes and 22.2 percent to main nodes. For curative resection cases with pT3 tumors more than 7 cm from the feeding artery, the rate to central nodes was 0 percent. CONCLUSIONS In T1 tumors, central node dissection is not required, but resection with proximal and distal 3-cm margins are required; in T2, central node dissection that includes the intermediate node should be performed in addition to resection with proximal and distal 5-cm margins. In T3 and T4, central node dissection that includes the main node should be performed in addition to resection with proximal and distal 7-cm margins. However, for T2 more than 5 cm from the primary feeding artery, and for T3 more than 7 cm from the primary feeding artery, proximal and distal resection alone may be adequate. |
