Angiogenesis in preinvasive, early invasive bronchial lesions and micropapillomatosis and correlation with EGFR expression

Abstract

To study the association between morphological changes of the bronchial epithelium and its angiogenic status evaluated by microvessel count (MVC), in order to gain a better understanding of bronchial carcinogenesis. Also, to correlate MVC with epidermal growth factor receptor (EGFR) expression. Eighty-three biopsy specimens were assessed for MVC: four normal bronchial epithelia, 23 hyperplasias, 26 metaplasias, two mild dysplasias, five moderate dysplasias, nine severe dysplasias, three carcinomas in situ, six early invasive squamous cell carcinomas (EIC) and five cases of micropapillomatosis. We observed a statistically significant difference in terms of MVC between EIC and all other subgroups and between micropapillomatosis and all other subgroups. There was also a statistically significant difference between micropapillomatosis and EIC. We did not observe any difference in MVC between normal mucosa, metaplasias, hyperplasias, dysplasias or carcinoma in situ. EGFR expression was higher in severe dysplasia, carcinoma in situ and EIC, whereas it was very low in micropapillomatosis. A statistically significant difference was observed in the expression profile of EGFR vs. MVC. EGFR expression was increased in severe dysplasia, whereas an increase in MVC occurred only in EIC. During bronchial carcinogenesis, except for micropapillomatosis, EGFR expression appears to be a prerequisite for neoangiogenesis in bronchial carcinogenesis.