Trastuzumab is the chemical name of the drug Herceptin. It is an IgG1 class antibody that treats HER2-positive breast cancer. HER2-positive breast cancer is a type of cancer that grows more rapidly and aggressive than other cancers. The HER2 gene is known as the human epidermal growth factor receptor 2. It is a protein that informs the cells whether or whether not to grow. At times, an unusual genetic mutation or additional copies of the gene which encodes HER2, causes the cells to grow when they are not supposed to. Furthermore, HER2-positive breast cancer has the same symptoms as the other kinds of breast cancer. Individuals usually discover a lump, or a mammogram discovers one. To find out if the breast cancer is HER2-positive, two common tests will be conducted. The first test is Immunohistochemistry (IHC) which calculates the number of HER2 on the cell’s surface with a score of zero to three. If the score is zero to one, then it is HER2-negative. If the score is two, then it is characterized as borderline. If the score is three, then it is HER2-positive. The second test is called the Fluorescence in situ hybridization (FISH). This test occurs when the IHC results are not visible, which usually happens when the IHC score is two. The FISH test uses specific labels that connect to the HER2 proteins. This type of test is more expensive and takes longer to receive results, but it gives a more accurate result.

Breast cancer is a type of heterogenous disease and is the most prevalent malignancy. Trastuzumab is a monoclonal antibody drug that specifically attacks the HER-positive protein. It blocks cancer cells from obtaining chemical messenges, which allows cell growth. The HER2 gene is a type of breast cancer cell that creates too many copies. This gene develops a protein called the HER2 receptor. The HER2 receptor obtains signals which activates growth and multiplication of the cells. Although, when breast cancer cells have an overflow of HER2 receptors, they can acquire a lot of growth signals. This results in an oversupply because the cells are multiplying and growing at a faster pace. The breast cancer cells that make too many copies of the HER2 gene are known as HER2-positive. Trastuzumab binds to the HER2 receptor and blocks it from obtaining the growth signals. By preventing the signals, this type of drug can stop or slow down the production of the cells. This drug clinically benefits every stage of HER2-positive cancer. Moreover, trastuzumab is given by an intravenous infusion only, which is delivered into the bloodstream directly. The occurrence of this treatment will depend on if the individual is receiving other medications with it. If an individual has an early stage of HER2-positive breast cancer, then they will receive both Trastuzumab and a chemotherapy schedule. If an individual has a metastatic HER2-positive breast cancer, then they will be treated with Trastuzumab as long as they are receiving benefits from it and without any bad side effects.

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