Chemotherapy refers to special medicines that work to kill cancer cells. Your doctor may recommend chemotherapy if you are at risk of having your cancer spreading beyond the breast or if you already have cancer that has spread. Chemotherapy is not used for cancers with a low risk of spreading to other parts of the body.
You may need chemotherapy if:
- The cancer was more than a centimeter (half an inch).
- There was cancer in the underarm lymph nodes.
- The cancer had the potential to grow quickly. This kind of cancer may be described on your pathology report by words like:
- high grade
- lymphatic invasion
- vascular invasion
- high growth rate
For men with hormone-receptor-positive cancer, hormonal therapy is usually the treatment of choice. If the cancer recurs or progresses on hormonal therapy, then chemotherapy may be added.
Chemotherapy may be given through an IV placed in your vein or by pills. Your doctor may put in a "port." This is a plastic device that sits just under the upper chest or upper arm and empties into a blood vessel. A needle fits into the port to give chemotherapy or to take blood for tests.
Chemotherapy may be given for a few days with a week or more off before the next dose. This cycle of treat-then-rest is repeated until the treatment course is finished. Depending on what medicines your doctor prescribes, the chemotherapy will usually be over in about 3-6 months.
Often two or more chemotherapy medications are used at the same time or one after the other. This will improve the chance of killing the different kinds of breast cancer cells that come from the same cancer. The medication combinations are known by the first letters in the medication names.
Here are a few of the most commonly used chemotherapy combinations:
- AC±T: Adriamycin (chemical name: doxorubicin) with Cytoxan (chemical name: cyclosphosphamide), with or without Taxol (chemical name: paclitaxel) or Taxotere (chemical name: docetaxel)
- TAC: involves the same medicines as above but in a different order
- AT: Adriamycin with Taxol or Taxotere
- CMF: Cytoxan, methotrexate, and fluorouracil (also called 5-FU or 5-fluorouracil)
- CAF: Cytoxan, Adriamycin, and fluorouracil
- CEF: Cytoxan, Ellence (chemical name: epirubicin), and fluorouracil
- FAC or CAF: fluorouracil, Adriamycin, and Cytoxan; these drugs are given in different orders
Other chemotherapy medicines that may be used alone or in combination include:
- Xeloda (chemical name: capecitabine): A pill taken to treat advanced (metastatic) breast cancer.
- Gemzar (chemical name: gemcitabine): Taken in combination with Taxol to treat advanced breast cancer.
- Navelbine (chemical name: vinorelbine): An intravenous (IV) chemotherapy that is used in patients with metastatic breast cancer. Navelbine is approved for second-line therapy — after an initial chemotherapy (first-line) regimen has been used and has stopped working.
- Abraxane (chemical name: albumin-bound or nab-paclitaxel): An injectable formulation of paclitaxel for treating metastatic breast cancer. Abraxane is approved as second-line therapy.
Your doctor will tell you which medication combination is likely to work best for you.
Chemotherapy attacks all the cells in your body that are fast-growing. Cancer cells tend to grow fast—but so do cells in your mouth, nose, and blood. The cells on your head that make hair are also fast-growing, and so are cells in your immune system and digestive system.
When chemotherapy affects normal cells, it can cause side effects including:
- vomiting and diarrhea
- mouth sores
- tiredness and fatigue
- higher risk of infection
- hair loss
- aches and discomfort
- changes in taste and smell
Medicines can take away or reduce most of the side effects. You will be able to take some of these medicines before and after each treatment. Most side effects go away within weeks or months after the end of chemotherapy treatment.
Chemotherapy medicines can be given one at a time or in combination with other chemotherapies. But chemotherapy is not usually given at the same time as hormonal therapy. Chemotherapy may also be delivered together with Herceptin (chemical name: trastuzumab), a targeted form of therapy for people with HER2-positive disease.