COMPARATIVE-ANALYSIS OF THE EXPRESSION OF TENASCIN AND ESTABLISHED PROGNOSTIC FACTORS IN HUMAN BREAST-CANCER

Tenascin is an extracellular matrix glycoprotein expressed during morp hogenesis in embryonal life. It reappears in the stroma of benign and malignant tumors. The distribution of tenascin in variants of fibrocys tic disease and infiltrating breast carcinoma was assessed in cryostat sections by immunofluorescence using a polyclonal antibody. The tenas cin immunoreactivity was compared with various prognostic factors. In fibrocystic disease (n = 10), tenascin appeared as periductal and peri acinar bands. In infiltrating carcinomas (n = 32) the tenascin express ion was markedly increased. Tenascin immunoreactivity was noted around the ducts (78%), extended into the distal stroma (56%), or was distri buted in smaller (reticular) septa around and within tumor-cell nests (34%). Nineteen percent of infiltrating carcinomas did not express ten ascin. None of the patterns correlated with prognostic factors such as nodal metastasis, tumor necrosis, invasion of blood vessels, or with flow cytometry results, such as ploidy and S-phase fraction. However, a significantly higher reticular and periepithelial tenascin expressio n was noted in cases with increased stromal inflammatory reaction. The se findings indicate that the appearance of tenascin is neither an ind icator of malignancy nor predictive of invasiveness or metastasis but that it is related to local inflammatory response.