HER-2 / neu markers in serum

Reference values ​​of HER-2 / neu concentration in blood serum - less than 15 ng / ml.

The HER-2 / neu - human epidermal growth factor receptor is a protein found on normal cells of epidermal origin with a molecular weight of 185,000. It consists of

3 functional parts: internal( cytosolic), short transmembrane and extracellular. The cytoplasmic region of the HER-2 / neu receptor molecule has tyrosine kinase activity and is responsible for signal transmission. The hydrophobic transmembrane portion connects the intracellular kinase and extracellular ends of the receptor. As a result of proteolytic processes, the extracellular part of the HER-2 / neu receptor enters the blood, where it can be identified. It is a glycoprotein with a molecular mass of 97,000-115,000.

Until recently, the presence of HER-2 / neu receptors in breast cancer patients was determined histochemically after the puncture of the tumor. These receptors are found only in 20-30% of women with breast cancer. The main goal of the histochemical study is to determine the indications for the treatment of trastuzumab( AT to HER-2 / neu receptors), which is shown when more than 10% positive cells( 2+ or 3+) are detected. Later it was found out that a significant number of patients with breast cancer respond positively to trastuzumab treatment with a negative histochemical result.

A test system for the quantitation of HER-2 / neu in blood serum has now been obtained, which correlates well with histochemical data. An increase in serum HER-2 / neu concentration is observed in women with breast cancer, especially in the presence of metastases. The value of 15 ng / ml is used as the separation point. Values ​​above this level indicate HER-2 / neu-positive breast cancer. Elevated levels of HER-2 / neu strongly correlate with poor prognosis, low survival and aggressive course of the disease( such tumors have high proliferative and metastatic activity).Effective specific( trastuzumab), hormonal and chemotherapy are accompanied by a decrease in the level of HER-2 / neu in the serum.

Serum HER-2 / neu determination is used:

■ for monitoring metastatic breast cancer;

■ for the selection of patients for specific therapy( zomab trust);

■ for the diagnosis of recurrences of breast cancer;

■ to determine the prognosis and course of breast cancer;

■ for monitoring specific therapy, as well as for treatment with hormonal and chemotherapeutic drugs.