Immunohistochemical study, in situ hybridization and computerized image analysis of colorectal epithelial progression from adenoma to carcinoma

ABSTRACT

This work aimed to study formalin fixed, paraffin embedded tissues from 60 cases of adenomas and 100 cases of carcinomas from patients who underwent surgery for the removal of colorectal adenoma and/or carcinoma in the VAPHS [Veterans Administration of Pittsburgh Healthcare System] and UPMC [University of Pittsburgh Medical Centre]. These cases included 28 adenomas with a definite evidence of progression to carcinoma. Proliferation and apoptosis in normal colonic mucosa, adenomas and carcinomas were determined and related to the expression of cell cycle and apoptosis associated proteins [Ki-67, bcl-2, bax and p53] using streptavidin biotin, in situ hybridization and computerized image analysis techniques. Bcl-2 expression reached its highest level in adenomas, followed by carcinomas, which displayed a higher level than adjacent normal mucosa in the same specimen. There was a progressive increase in bax, p53, Ki-67 and ApopTag labeling indices along normal-adenoma-carcinoma sequence. It was found that bax LI was significantly higher in large adenomas and p53 LI and Ki67 LI were significantly lower in tubular adenomas