Breast Cancer 

Breast cancer is the most common cancer among women. 

There are many types of breast cancer that differ in their capability of spreading (metastasize) to other body tissues. 

The causes of breast cancer are not yet fully known, although a number of risk factors have been identified.

•  There are many different types of breast cancer. 
•  Breast cancer symptoms and signs include 
•  a lump in the breast or armpit, o bloody nipple discharge, 
• inverted nipple, 
• orange-peel texture or dimpling of the breast's skin, 
• breast pain or sore nipple, 
• swollen lymph nodes in the neck or armpit, and 
• a change in the size or shape of the breast or nipple. 
• Breast cancer is diagnosed during a physical exam, by a self-exam of the breasts, mammography, ultrasound testing, and biopsy. 
• Treatment of breast cancer depends on the type of cancer and its stage (0-IV) and may involve surgery, radiation, or chemotherapy.

There are many risk factors that increase the chance of developing breast cancer. Although we know some of these risk factors, we don't know the cause of breast cancer or how these factors cause the development of a cancer cell. 

We know that normal breast cells become cancerous because of mutations in the DNA, and although some of these are inherited, most DNA changes related to breast cells are acquired during one's life. 

Proto-oncogenes help cells grow. If these cells mutate, they can increase growth of cells without any control. Such mutations are referred to as oncogenes. Such uncontrolled cell growth can lead to cancer. 

Although breast cancer can be diagnosed by the above signs and symptoms, the use of screening mammography has made it possible to detect many of the cancers early before they cause any symptoms. Women should have the choice to begin annual screening between 40-44 years of age. Women age 45 and older should have a screening mammogram every year until age 54. Women 55 years of age and older should have biennial screening or have the opportunity to continue screening annually. Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or longer.

A bio similar is a new type of biologic drug. A biologic drug or product is made from living things, such as antibodies or proteins. 

Herceptin (chemical name: trastuzumab) and Avastin (chemical name: bevacizumab) are two examples of biologic drugs used to treat breast cancer. Both Herceptin and Avastin are created from monoclonal antibodies, a type of protein made in the lab that can bind to substances in the body, including cancer cells. Because they’re made from living organisms, biologic drugs are much more complex to make than drugs that are made from a mixture of chemicals, such as acetaminophen (brand name: Tylenol) or pseudoephedrine (brand name: Sudafed). The structure of chemical drugs can be easily analyzed, identified, and duplicated. This is why there are so many generic drugs on the market. After the patent on a chemical drug expires, another manufacturer can make an exact copy of the drug. Because they are identical, generic drugs and name-brand drugs can be used interchangeably