Clinical and pathologic significance of the c-erbB-2 (HER-2/neu) oncogene.

Activation of the c-erbB-2 oncogene can occur by amplification of c-erbB-2 DNA and by overproduction of c-erbB-2 mRNA and c-erbB-2 protein. Approximately 20 percent of breast carcinomas show evidence of c-erbB-2 activation, which correlates with a poor prognosis primarily in patients with metastasis to axillary lymph nodes. Studies that have attempted to correlate c-erbB-2 activation with other prognostic factors in breast carcinoma have reported conflicting conclusions. The pathologic and clinical significance of c-erbB-2 activation in other neoplasms is unclear and should be assessed by additional studies.