All normal cells in your body divide and grow all the time in an ordered and controlled way. However, cancer cells divide and grow in a disordered and uncontrolled way. Chemotherapy destroys cancer cells by getting in the way of their ability to divide and grow. Different chemotherapy drugs work in different ways and interfere with the cancer cells at different times in their growth. This is why a combination of drugs is often used.
Primary breast cancer is breast cancer that is found in the breast and/or the lymph nodes (glands) under the arm (axilla) and which hasn’t spread anywhere else in the body. To decide whether or not you’re offered chemotherapy, various factors are looked at, such as the size of your breast cancer, whether the lymph nodes are affected, the grade of your cancer (how different your cancer cells are from normal breast cells and how quickly the cancer cells are growing) and the oestrogen receptor (ER) and hormone receptor (HER2) status Your general health and any other medical conditions will also be considered. This decision will be made by a medical oncologist.
Chemotherapy is commonly given in addition to surgery and/or radiotherapy for primary breast cancer. It is given to reduce the risk of the breast cancer returning and is known as adjuvant chemotherapy. Chemotherapy is usually started a few weeks after surgery, giving your body some time to recover from the effects of the operation.. In some circumstances chemotherapy is given before surgery. This is known as primary or neo-adjuvant chemotherapy. For example, it may be used to slow the growth of rapidly growing breast cancer and reduce the chance of it spreading to other parts of the body or to shrink a larger breast cancer before surgery. If you’re offered primary chemotherapy your specialist and/or breast care nurse will explain why.
Chemotherapy is administered orally or intravenously, and is most effective when given as a combination of 2 or more drugs. The drugs travel through the blood stream to reach the breasts and attack the rapidly dividing cancer cells. This therapy is given in cycles, wherein each session of chemotherapy is followed by a period of rest during which time your body can recuperate from the effects of treatment. The period of each cycle varies based on the type of drug used, and the duration of chemotherapy lasts for about 3 to 6 months depending on the severity of your cancer.
Since chemotherapy drugs are designed to target rapidly dividing cells they may also affect other rigorously dividing cells in the body such as the bone marrow cells, hair follicle cells and the cells lining the mouth or the intestine. Some of the most common side effects include:
The severity of the side-effects caused depends on the type of drug, its dosage, and the duration of your treatment. Your doctor monitor’s your response and side-effects you may develop from these drugs, and accordingly continues or changes the medications as needed.