Chemotherapy is a standard medicinal approach to treating various types of cancer(s). This approach takes powerful chemicals to kill the multiplying cancer cells within your body. Because chemotherapy medicines affect the body in its entirety and targets the healthy cells in your body too, it is used to treat advanced stage breast cancers. Note that chemotherapy can sometimes be used to treat an overactive immune system; disorders such as Lupus and rheumatoid arthritis. It is said that chemotherapy has been around since the time of Ancient Greeks, however it became useful in treating cancer in the 1940’s (chemocare.com). Side effects to this type of treatment depends on the chemotherapy cocktail and how your body responds to it. Your chemotherapy cocktail will likely differ from the patient next to you. Your cocktail is determined by several factors to include your age, grade of tumor and estrogen status.