Low frequency of bcl-2 expression in large non-polypoid colonic neoplasms.
Large non-polypoid colorectal adenomas that spread over the mucosa and morphologically flat lesions are included in a group called granule-aggregating tumours. These are uncommon in the West. We aimed to clarify the biological differences between granule-aggregating tumours and colorectal polypoid adenomas. We evaluated the extent of apoptotic cell loss and expression of bcl-2 and p53 oncoproteins in 26 granule-aggregating tumours and 19 polypoid adenomas. The mean apoptosis index value of granule-aggregating tumours was significantly higher than that of polypoid adenomas. Only two (7.7%) granule-aggregating tumours and 13 (68.4%) polypoid colorectal adenomas expressed bcl-2, while 12 (46.2%) granule-aggregating tumours and six (31.6%) polypoid colorectal adenomas were p53-positive. Our results show that the higher apoptosis index and frequent expression of bcl-2 oncoprotein differentiates granule-aggregating tumours from polypoid colorectal adenomas. We propose that large non-polypoid granule-aggregating tumours of the colorectum are a biologically distinct entity.
First Department of Surgery, Yamanashi University, School of Medicine, Yamanashi, Japan.
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Yamada
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Hasegawa
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Iino
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Eguchi
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Fujii
D000236:Adenoma / Q000378:metabolism*; D018256:Adenomatous Polyps / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D002467:Cell Nucleus / Q000378:metabolism; D003110:Colonic Neoplasms / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism; D004724:Endoscopy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis
D004277:DNA, Single-Stranded; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53