HER2

HER2: Human (epidermal growth factor) receptor 2, a receptor that plays an essential role in cell proliferation and differentiation. It is a member of a family of transmembrane tyrosine kinases. The 20 to 25 percent of breast cancers that over-express HER2 have a high rate of recurrence in the first two or three years after surgery. The HER2 gene is on the short arm of chromosome. Over-expression of this gene increases the malignancy of affected cancer cells, enhancing growth and proliferation and increasing their metastatic tendency. The monoclonal antibody drug trastuzumab (Herceptin) which blocks this receptor is effective in reducing the dangers of HER2-expressing breast cancers.