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 < 0.001), poor histology (51.9% vs. 19.3%, p = 0.008), and PWDA (3.7% vs. 25.0%, p = 0.015). The rates of LNM and PWDA were 8.4% and 36.1%, respectively, in T1 cancers. Regarding the 73 PWDA cases and 129 non-PWDA cases, the rates of LNM were 0.0% and 13.2%, respectively (p < 0.001). Among the 97 cases with lymphatic or venous invasion, the rates of LNM in 29 PWDA cases and 68 non-PWDA were 0% and 14.7%, respectively (p = 0.029). The agreement of the two pathologists for the diagnosis of PWDA was acceptable (kappa value > 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.
Highlights
Sepharose to purify calmodulinlike proteins from whole cells and from extruded trichocysts
Elution with a pH 8 .0 buffer containing EGTA released a small amount of protein (^-I% of the total eluted) from the affinity column, which consisted of a single polypeptide with the properties of calmodulin
The protein we have purified from whole cells and extruded trichocysts of Paramecium by fluphenazine affinity chromatography has the properties characteristic of Camodulin from many other sources
Summary
Sepharose to purify calmodulinlike proteins from whole cells and from extruded trichocysts. The purified protein from trichocysts is indistinguishable from that of whole cells; it is heat-stable, activates brain phosphodiesterase in a Ca'-dependent fashion, changes mobility on SIDS polyacrylamide gels in the presence of Ca", contains 1 mol of trimethyllysine/17 kdaltons, and has the amino acid composition characteristic of calmodulins. Calmodulin is a major component of purified, extruded trichocysts, of which it represents between 1 and 10% by mass. Trichocysts are specialized secretory organelles found in Paramecium, each enclosed in membranous vesicles lying just beneath the cell surface [1, 2]. We show here that one of these major components of extruded trichocysts is calmodulin, a widely distributed Ca"-binding protein known to mediate the regulation of a wide variety of enzymes by Ca" [17, 18]
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