Clinicopathologic Analysis of Lateral Margin Measured by Whole-mount Section in T3 Rectal Cancer.

ABSTRACT

PURPOSE: Total mesorectal excision is a standard technique for rectal cancer. The whole-mount section can encompass the entire specimen, so it is a more appropriate for measuring circumferential margin than conventional section. We analyzed the clinical characteristics and prognosis based on lateral margins measured by whole-mount sections. MATERIALS AND METHODS: Medical records of patients who were operated on for T3 rectal cancer from 2005 to 2015 were reviewed retrospectively. A total of 154 patients were included. The slides of the whole-mount sections were re-reviewed by a single pathologist. RESULTS: We divided the groups according to the length of the lateral margin (LM 1mm, 1.5mm and 2mm). There was significantly frequent lymphovascular invasion and N state was higher when LM was short in all groups. There were more micrometastasis in group LM.