Breast Cancer - Herceptin and HER2

One of the biggest and most exciting advances in recent history in the fight against breast cancer is a drug called Herceptin. (Trastuzumab) The drug has shown to be very successful against certain types of advanced breast cancers. Some more recent clinical trials have shown that herceptin may also be successful against certain types of earlier stage breast cancers. Herceptin has been approved for use in 1998 by the FDA.

By certain types of cancers we are referring to those that over-express a protein that is called HER2. HER2 stands for human epidermal growth factor receptor 2. HER2 can be found on the surface of cells and it is what is responsible for keeping the growth of the cell in check. When HER2 malfunctions and begins to produce too much of itself due to a mutation it can cause the cells to produce too much of themselves too quickly. This in turn can make cancers behave in a much more aggressive manner. The HER2 over-expression is a factor in 20% to 30% of breast cancer occurrences.

The official scientific big word description of Herceptin is that it is a monoclonal antibody, engineered via biotechnology. The way it works is by attaching itself to any cells that are overproducing the HER2 protein. It attacks the protein receptors which then slows the growth of the cells down. It targets the HER2 protein as opposed to traditional types of treatment which tend to destroy all fast growing cells in their path, healthy or cancerous. This is a big improvement over certain types of chemotherapy. The development of targeted treatments like Herceptin is the wave of the future.

So how does a breast cancer patient receive herceptin? Their cancer must show that it over-expresses the HER2 protein. This is determined by having a pathologist test the cancerous cells that were removed from the breast during surgery. He or she will stain the tissue with a solution that will highlight any instance of overproduction of HER2. If a patient has the HER2 over-expression present, they are considered to be HER2 positive and therefore it could be possible to treat their cancer with herceptin if needed.

Herceptin is not for everyone. It is approved for treatment of women with advanced cancer in combination with the chemotherapy drug, paclitaxel. There are side effects associated with the drug and one of those includes cardiotoxicity which can cause serious heart problems in patients. Therefore heart monitoring before, during and after treatment is crucial. Less serious side effects include fever, chills, increased cough, diarrhea and weakness. If herceptin is given with chemotherapy, nausea is possible. Other moderately severe side effects include loss of white blood cells and anemia.

A diagnosis of breast cancer can be a frightening thing, especially if you are in the percentage of patients that have the more aggressive HER2 cancer. Knowing that there is another treatment that has been proven to be effective against those types of cancers brings increased hope of survival to these women and men.