Clinical Pathophysiological Characteristics and Immunohistochemistry of β-catenin Protein and p53 Protein, and Analysis on Microsatellite Instability in Colorectal Laterally Spreading Tumors

Haruki Yamada¹⁾, Hiroshi Iino¹⁾, Hideki Fujii¹⁾, Hideo Eguchi²⁾, Hiromasa Hasegawa³⁾ and Yoshiro Matsumoto¹⁾

¹⁾First Department of Surgery, Yamanashi Medical University, ²⁾Department of Surgery, Municipal Uenohara Hospital, ³⁾Department of Oral Pathology, Matsumoto Dental University

Aims: We studied clinical pathophysiological characteristics and the tumorigenic and carcinogenic process from immunohistochemistry of β-catenin protein and p53 protein and microsatellite instability (MSI) analysis in 31 lesions in 31 patients of laterally spreading tumor (LST) of the large intestine. Results: LSTs were divided into three groups, of which Granular-Homogenous (G-H), Granular-Nodular mixed (G-N) and Non Granular (NG). The rate of involving cancer was significantly higher in group G-N and NG than in group G-H, particularly in group NG, in which all tumors with a diameter of less than 20 mm were cancerous. The incidence of p53 protein increased as heteromorphism advanced. The incidence of β-catenin protein was high in the nucleus and cytoplasm regardless of heteromorphism. We saw no MSI-H (igh) case. Conclusions: 1) group NG was high in biological malignancy. 2) β-catenin protein played a role in LST tumorigenesis.3) The carcinogenic process was principally LOH.4) LST was not one distinct concept-disease.

Key words
colorectal laterally spreading tumor, β-catenin protein, p53 protein, microsatellite instability

Reprint requests
Haruki Yamada First Department of Surgery, Yamanashi Medical University 1110 Shimokato, Tamaho-cho, Nakakoma-gun, Yamanashi, 409-3898 JAPAN

Accepted
October 31, 2001

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