Abstract

Automated quantitative computer-assisted morphometric analysis of immunohistochemical expression of markers of neoplastic development and progression in experimentally induced and in human neoplasms showed very high sensitivity and reproducibility, allowing analysis of large numbers of cell and tissue components. Totals of 26 million pixels, 25,000 cells and 1500 vessels were examined, with a sensitivity exceeding 99% and reproducibility exceeding 99%.

The total expression of proliferating cell nuclear antigen (PCNA) and p53 increased consistently during 7H-dibenz[c, g] carbazole (DBC)-induced formation of dysplasias and squamous cell carcinomas (SCC:s) in hamster lung. In dysplasia, nuclear size and PCNA staining intensity increased; in SCC:s nuclear size decreased. In a retrospective study on archival material of human laryngeal squamous cell carcinomas, the occurrence and location of PCNA-positive cells were specifically related to the degree of differentiation. In SCC:s nuclear size decreased, while shape alterations and PCNA staining intensity increased in relation to degree of malignancy.

In DBC-induced respiratory carcinogenesis increased collagen matrix synthesis occurred prior to neoplasm development. Among squamous cell carcinomas, in well-differentiated tumors, collagen deposition increased, as did fiber size, in moderately differentiated tumors collagen synthesis and the deposition of new collagen decreased. The increase in transforming growth factor beta expression in differentiated cells and in the matrix was isoform-specific.

Increased angiogenesis in laryngeal tumor development occurred in preneoplastic states and in SCC: s, inversely related to the degree of differentiation. In well-differentiated neoplasms the vessels were lying in the direction of the BM, in moderately differentiated neoplasms vessels were lying in the direction of tumor invasion and in poorly differentiated neoplasms irregular, partly abnormal vessels intermixed with tumor cells. Small regular vessels predominated in benign conditions and large, irregular vessels in malignant conditions.

Experimental models provided the advantage of examining homogenous, well-characterized neoplasm progression without interfering with the process. Morphometric methods provided detailed information on large numbers of cells, useful for studies of tumor behavior and with potential clinical applications.