Thus, the protein products of the amplified c-erbB-2 gene may have a role in the evolution of adenocarcinomas, as does the EGF receptor in some squamous-cell carcinomas.
The use of immunohistological staining to detect the level of expression of the c-erbB-2 protein in human breast adenocarcinomas may be of value in predicting tumour behaviour.
Southern blot analysis of paired tumor and normal lung samples demonstrated that amplification of the c-erbB-2 gene is rare in NSCLC (2/60) and not restricted to adenocarcinomas.
Using avidin-biotin-peroxidase techniques and monoclonal antibody TA1, 313 archival primary adenocarcinomas of the breast were evaluated for c-erbB-2 overexpression; 290 of these were used for multiparametric statistical analysis.
Immunohistochemical staining of tumor tissue sections with p185 HER-2/neu antibodies demonstrated that only the 3 gastric adenocarcinomas with corresponding HER-2/neu gene amplification displayed membrane immunoreactivity.
In cervical adenocarcinomas, expression of c-myc was seen in 5 of 7 cases (71.6%), EGFR in all cases and c-erbB-2 in 2 of 7 cases (28.6%). c-myc immunoactivity was observed as nuclear or cytoplasmic stain or both, EGFR as membrane and cytoplasmic stain, c-erbB-2 as membrane stain.
Poorer survival rates and elevated recurrence rates following treatment have been shown in patients whose breast adenocarcinomas demonstrate increased c-erbB-2 expression.
Amplification and/or overexpression of the erbB-2 gene have been demonstrated in 20-30% of adenocarcinomas of the breast, ovary, lung, and stomach and are associated with aggressive clinical course and poor prognosis.
These findings imply that a significant proportion of invasive mammary adenocarcinomas expressing c-erbB-2 protein is derived from ductal in situ carcinomas of the comedo type.
It is also concluded that errors in the onco-suppressor gene p53, and especially in the external and internal domains of c-erbB2, which is also often expressed in Barrett's mucosa, may be implicated in the development of adenocarcinoma of the oesophagus.
We conclude that immunohistochemical positivity for c-erbB-2 is an indicator of aggressiveness in both adenocarcinoma and adenocarcinoma in pleomorphic adenoma of the major salivary glands.
These results suggest a role for the NEU gene product in the physiology of benign ovarian surface epithelium and the neoplastic epithelium of preinvasive borderline and some invasively malignant adenocarcinomas.
In marked contrast, c-erbB-2 proto-oncogene expression was found only in adenocarcinoma cells, and thus can be used as a marker for malignancy in diagnostic respiratory cytopathology.