Amplification of ERBB-2 was detected in 14 out of 63 (22%) cases of breast carcinoma, in 1 out of 23 patients with ovarian cancers, in 1 out of 19 cases of colon carcinoma and in 1 out of 27 patients with thyroid cancer.
Amplification of the HER-2 (c-erbB-2) gene and overexpression of the p185HER-2 gene product is found in approximately one-third of primary human breast and ovarian cancers and is associated with a poor clinical outcome of early relapse and death.
Overexpression of the EGFR and c-erbB-2 oncoproteins was found in respectively 3/31 (9%) and 10/31 (32%) ovarian carcinomas, 13/18 (72%) and 7/18 (38%) cervical carcinomas, and 2/15 (13%) and 2/15 (13%) endometrial carcinomas.
Although the human neu gene was shown to be amplified/overexpressed in a large portion of human breast and ovarian cancer, no reports indicate that the human neu gene is activated by a point mutation in human tumor.
Therefore, neither c-erbB2 gene amplification nor c-erbB2 protein over-expression appears to be a significant prognostic marker in patients with ovarian carcinoma.
No significant association was found between AKT2 amplification and amplification of the proto-oncogenes MYC and ERBB2, suggesting that amplification of AKT2 defines an independent subset of breast and ovarian cancers.
Nevertheless, few reports suggest that c-erbB-2/neu, which is a prognostic marker in breast cancer, epidermal growth factor receptor (EGFR), which is overexpressed in a variety of neoplasms, and fibroblast growth factor-3 (FGF-3/INT-2), which has been found to be amplified in breast and ovarian cancer, could be implicated in the development of endometrial adenocarcinoma.
These data suggest that amplification of the C-erbB-2 gene may play a role in the pathogenesis of ovarian carcinoma; it is frequently observed in advanced ovarian cancer and is associated with poor prognosis for these patients.
Overexpression of HER-2/neu, a 185-kDa tyrosine kinase growth factor receptor, in human ovarian cancers has been correlated with a poor prognosis for survival of the disease.
The finding that erbB2 product in ovarian cancer is mostly localised in cytoplasm and not in the membrane as in breast cancer and that it has a lower molecular weight than the p185 in breast cancer suggest that this oncogene plays a different biological role in these two neoplasms.
Although expression of the HER-2/neu oncogene may be of some prognostic importance in advanced ovarian cancer, its role in early-stage disease has not been established.