HER-2/neu gene product in serum - An oncoprotein in the diagnosis and therapy of breast carcinoma

The HER-2/neu oncogene codes a protein of the family of epidermal growth factor receptors. The extracellular domain has a MW from 95-105 kDa and is shed into the blood. In some patients with malignant tumors there is a high expression of HER-2/neu connected with high levels of HER-2/neu protein in the serum. High concentrations signal aggressive growth, bad prognosis and shorter survival. The reference range lies between 4.0 and 14.0 ng/ml with a mean of 9.0 ng/ml There is a significant difference of values between patients with and without metastases, but not between healthy people and patients without metastases. The advantage of this parameter lies in the early diagnosis of recurrence in the therapy of metastasizing breast carcinomas especially on treatment with Herceptin.