title: Clinicopathologic evaluation of the trend toward histologically poor differentiation with submucosal invasion in superficial early colorectal adenocarcinomas.
abstract: We examined differences in the degree of differentiation in intramucosal and submucosal areas of involvement in early colorectal adenocarcinomas of 131 patients and compared these findings with tumor morphology. In addition, K-ras and p53 protein expression was determined in cases where poorly differentiated adenocarcinoma was detected in the submucosa. We identified 6 patients with both intramucosal differentiated (well-to-moderately differentiated) adenocarcinoma and submucosal poorly differentiated adenocarcinoma (MwSp). The morphological tumor type was superficial in all MwSp cases. The observed MwSp adenocarcinomas had a significantly higher frequency of lymphatic invasion than the more common superficial type of adenocarcinoma. Genetic analysis of these MwSp lesions was carried out using the polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method to detect the presence of K-ras codon 12 point mutations, and an immunologic staining technique was used to identify the presence of p53 protein overexpression. The K-ras mutation rate was 33.3%, and the p53 overexpression rate was 66.7% for the MwSp adenocarcinomas. Our findings suggest that the rapidly reduced histologic differentiation observed in some of these superficial colorectal adenocarcinomas may play a role in their higher degree of invasiveness.
authors.affiliation: Institute of Gastroenterology, Tokyo Women's Medical University, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Suzuki
authors.forename: K
authors.initials: K
authors.lastname: Nagasako
authors.forename: T
authors.initials: T
authors.lastname: Fujimori
authors.forename: Y
authors.initials: Y
authors.lastname: Ono
authors.forename: S
authors.initials: S
authors.lastname: Suzuki
authors.forename: N
authors.initials: N
authors.lastname: Hayashi
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D003106:Colon / Q000473:pathology; D015179:Colorectal Neoplasms / Q000473:pathology*; D011905:Genes, ras / Q000235:genetics; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D009154:Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012007:Rectum / Q000473:pathology; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis
chemical_list: D016159:Tumor Suppressor Protein p53