Gastroenterology Research and Practice (Jan 2018)
Pure Well-Differentiated Adenocarcinoma Is a Safe Factor for Lymph Node Metastasis in T1 and T2 Colorectal Cancer: A Pilot Study
Abstract
Background and Aims. Various risk factors for lymph node metastasis (LNM) have been reported in colorectal T1 cancers. However, the factors available are insufficient for predicting LNM. We therefore investigated the utility of the new histological factor “pure well-differentiated adenocarcinoma” (PWDA) as a safe factor for predicting LNM in T1 and T2 cancers. Materials and Methods. We reviewed 115 T2 cancers and 202 T1 cancers in patients who underwent surgical resection in our center. We investigated the rates of LNM among various clinicopathological factors, including PWDA. PWDA was defined as a lesion comprising only well-differentiated adenocarcinoma. The consistency of the diagnosis of PWDA was evaluated among two pathologists. In addition, 72 T1 cancers with LNM from 8 related hospitals over 10 years (2008–2017) were also analyzed. Results. The rates of LNM and PWDA were 23.5% and 20.0%, respectively, in T2 cancers. Significant differences were noted between patients with and without LNM regarding lymphatic invasion (81.5% vs. 36.4%, p 0.5). A multicenter review showed no cases of PWDA among 72 T1 cancers with LNM. Conclusions. PWDA is considered to be a safe factor for LNM in T1 cancer.