Chemotherapy for breast cancer

Chemotherapy uses anticancer (or cytotoxic) drugs to destroy cancer cells. Many women with breast cancer have chemotherapy. Your healthcare team will consider the type of breast cancer you have and your personal needs to plan the drugs, doses and schedules of chemotherapy. You may also receive other treatments to help lessen the side effects of chemotherapy.

Chemotherapy is given for different reasons. You may have chemotherapy to:

• shrink a large tumour before surgery (called neoadjuvant chemotherapy) when the cancer hasn’t spread outside the breast or lymph nodes
• destroy cancer cells left behind after surgery and reduce the risk that the cancer will come back (recur) (called adjuvant chemotherapy)
• treat cancer that comes back
• relieve pain or control the symptoms of advanced breast cancer (called palliative chemotherapy)

Chemotherapy is usually a systemic therapy. This means that the drugs travel through the bloodstream to reach and destroy cancer cells all over the body, including those that may have broken away from the primary tumour in the breast.

Chemotherapy is generally given every 3 weeks. Sometimes it is given every 2 weeks (called a dose-dense regimen). Studies have shown that a dose-dense regimen may further lower the risk that breast cancer will come back and it may improve survival.

The level of risk of recurrence of breast cancer after surgery is based on:

• the size and grade of the tumour
• if the cancer has spread to lymph nodes
• if the cancer has spread to lymph vessels or blood vessels
• the hormone receptor status
• the HER2 receptor status

Chemotherapy is always offered to women who have breast cancer with a high risk of recurrence because it significantly reduces risk. Women with a low risk of breast cancer recurrence are not usually offered chemotherapy because it does not significantly reduce risk.

If you have breast cancer with a moderate risk of recurrence, you may be offered chemotherapy after the healthcare team has discussed the risks and side effects of chemotherapy with you.

Chemotherapy may also be offered to women with a low or moderate risk of recurrence who have a high score on the Oncotype DX test.

Your doctors will consider your overall health when deciding if chemotherapy is an option. For example, women with heart disease may not be able to have certain drugs because they can cause more heart damage. Other health problems can also affect whether or not you can have chemotherapy.

If chemotherapy and radiation therapy are both part of your treatment plan, radiation treatments are usually started after chemotherapy is finished. This is because the side effects of some drugs given for breast cancer may be worse when you are also having radiation therapy.

Many different drugs and combinations of drugs can be offered for breast cancer.

The type of breast cancer you have, your overall health and your personal situation and preferences will affect the type of chemotherapy drugs your doctor offers. For example, if you’ve already had chemotherapy for breast cancer, your doctor may not be able to give you more of the same drugs. You should also talk to your doctor about your priorities, such as having fewer side effects or wanting the option to have children in the future.

The different chemotherapy drugs and combinations of drugs offered will depend on the stage of the breast cancer.

Doctors usually offer chemotherapy to treat early stage (stages 1A, 1B and 2A) breast cancer with a high risk of recurrence or locally advanced (stages 2B, 3A, 3B and 3C) breast cancer. Chemotherapy for these stages of breast cancer is generally given as a combination of several drugs because research shows that giving them together is more effective than giving each drug alone.

The following combinations of drugs may be offered. Most of these drugs are given by a needle in a vein (intravenously):

• AC-T – doxorubicin (Adriamycin) and cyclophosphamide (Procytox) followed by paclitaxel (Taxol)
• T-AC – paclitaxel or docetaxel (Taxotere) followed by doxorubicin and cyclophosphamide
• TC – paclitaxel and cyclophosphamide
• doxorubicin and cyclophosphamide followed by docetaxel
• CAF (or FAC) – cyclophosphamide (as a pill), doxorubicin and 5-fluorouracil (Adrucil, 5-FU)
• FAC followed by docetaxel or paclitaxel
• CEF (or FEC) – cyclophosphamide (as a pill), epirubicin (Pharmorubicin) and 5-fluorouracil
• CEF followed by docetaxel or paclitaxel
• EC – epirubicin and cyclophosphamide
• carboplatin (Paraplatin, Paraplatin AQ) and docetaxel
• docetaxel and cyclophosphamide
• adjuvant capecitabine (Xeloda) after a neoadjuvant chemotherapy combination

Women with HER2-positive breast cancer may also be given a targeted therapy drug with some chemotherapy combinations. Trastuzumab (Herceptin) is usually the targeted therapy given.

Advanced (metastatic) breast cancer means that the cancer has spread to other parts of the body. It is stage 4 breast cancer.

Doctors often use one chemotherapy drug to treat advanced breast cancer because it causes fewer side effects than a combination of drugs. However, combination chemotherapy may also be used.

There is no standard drug or drug combination for advanced breast cancer. Chemotherapy is given as long as the cancer responds to it and the side effects do not cause problems. Once the cancer no longer responds to the treatment, doctors may offer a different drug.

The following single drugs may be used:

• doxorubicin
• pegylated liposomal doxorubicin (Caelyx)
• paclitaxel
• nab-paclitaxel (Abraxane)
• capecitabine
• gemcitabine (Gemzar)
• vinorelbine (Navelbine)
• cyclophosphamide
• carboplatin
• docetaxel
• cisplatin (Platinol AQ)
• epirubicin

The following combinations of chemotherapy drugs may be used for advanced breast cancer:

• CAF (or FAC) – cyclophosphamide, doxorubicin and 5-fluorouracil
• CEF (or FEC) – cyclophosphamide, epirubicin and 5-fluorouracil
• AC – doxorubicin and cyclophosphamide
• EC – epirubicin and cyclophosphamide
• docetaxel and capecitabine
• gemcitabine and paclitaxel
• gemcitabine and carboplatin

Women with HER2-positive breast cancer may also be given one or more of the following targeted therapy drugs with some of the chemotherapy combinations listed above:

• trastuzumab (Herceptin)
• pertuzumab (Perjeta)
• trastuzumab emtansine (Kadcyla)

The treatment offered for recurrent breast cancer will depend on if the breast cancer has not spread beyond the breast and the lymph nodes (called localized cancer) or if it has spread (metastasized) to other parts of the body.

Localized recurrent breast cancer is treated the same way as early or locally advanced breast cancer. Your healthcare team will offer your treatment based on what chemotherapy drugs or other treatments you have already had for breast cancer. Treatment is also based on how long after your first treatments the cancer recurred.

Metastatic recurrent breast cancer is treated like breast cancer that was metastatic at the time of diagnosis.

Your healthcare team may offer the following drugs to help your body cope with the side effects of cancer treatment, especially if you are being given chemotherapy over a shorter amount of time (dose-dense chemotherapy).

Colony-stimulating factors may be given with some combinations of chemotherapy drugs used to treat breast cancer. They help improve low white blood cell counts.

Antinausea drugs may be offered to treat nausea and vomiting from some chemotherapy drugs used to treat breast cancer.

Antibiotics may be prescribed to lower the chance of developing an infection during chemotherapy.

Side effects can happen with any type of treatment for breast cancer, but everyone’s experience is different. Some people have many side effects. Other people have few or none at all.

Chemotherapy may cause side effects because it can damage healthy cells as it kills cancer cells. If you develop side effects, they can happen any time during, immediately after or a few days or weeks after chemotherapy. Sometimes late side effects develop months or years after chemotherapy. Most side effects go away on their own or can be treated, but some side effects last a long time or become permanent.

Side effects of chemotherapy will depend mainly on the type of drug, the combination of drugs used, the dose, how it is given and your overall health. Some common side effects of chemotherapy drugs used for breast cancer are:

• low blood cell counts
• infection
• nausea and vomiting
• sore mouth and throat
• hair loss
• diarrhea
• constipation
• fatigue
• loss of appetite
• treatment-induced menopause
• cognitive changes
• nervous system damage
• fertility problems

Tell your healthcare team if you have these side effects or others you think might be from chemotherapy. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.

Details on specific drugs change regularly. Find out more about sources of drug information and where to get details on specific drugs.

Find out more about chemotherapy and side effects of chemotherapy. To make the decisions that are right for you, ask your healthcare team questions about chemotherapy.