Chemotherapy for breast cancer

Chemotherapy (chemo) is the use of cancer-killing drugs. These drugs can be put into a vein, given as a shot, or taken as a pill or liquid. They enter the bloodstream and reach most parts of the body, making this treatment useful for cancers that have spread to distant organs. While these drugs kill cancer cells, they also damage some normal cells, which can lead to side effects.

When is chemo used?

There are several cases where chemo may be used.

After surgery (adjuvant chemo): When treatment given to patients after surgery who do not seem to have any spread of cancer is called adjuvant therapy. When used this way after breast-conserving surgery or mastectomy, chemo reduces the risk of the breast cancer coming back.

Even in the early stages of the disease, cancer cells can break away from the first breast tumor and spread through the bloodstream. These cells don't cause symptoms, they don’t show up on an x-ray, and they can’t be felt during a physical exam. But if they are allowed to grow, they can form new tumors in other places in the body. Adjuvant chemo can be given to find and kill these cells, which lowers the chance that the cancer will come back later.

Before surgery (neoadjuvant chemo): Chemo given before surgery is called neoadjuvant therapy. The major benefit of this approach is that it can shrink large cancers so that they are small enough to be removed with breast-conserving surgery instead of mastectomy. Another possible advantage is that doctors can see how the cancer responds to the chemo. If the tumor does not shrink, then different drugs may be used. Giving chemo before surgery works as well as giving the same treatment after surgery (as adjuvant treatment) in terms of lowering the chance that the cancer will come back later.

For advanced breast cancer: Chemo can also be used as the main treatment for women with cancer that has already spread outside the breast and nearby lymph nodes when it is found, or if it spreads after the first treatments.

How is chemo given?

In most cases, chemo works best if more than one drug is used. Doctors give chemo in cycles, with each round of treatment followed by a rest period. The time between cycles (the beginning of each treatment) is most often 2 or 3 weeks, but can vary according to the drug or combination of drugs being used. For early stage breast cancer, the total course of treatment usually lasts for 3 to 6 months. Treatment is often longer for advanced breast cancer.

Dose-dense chemo: Doctors have found that giving the cycles of certain chemo drugs together for neoadjuvant or adjuvant treatment can lower the chance that the cancer will come back and improve survival in some women. This usually means giving the same chemo that is normally given every 3 weeks but giving it every 2 weeks. A drug called a growth factor is also given to help boost the white blood cell count. This approach can lead to more side effects and be harder to take, so it is only used for treatment in women with a higher chance of the cancer coming back after treatment.

Possible side effects

The side effects of chemo depend on the type of drugs used, the amount given, and the length of treatment. You could experience some of these short-term side effects:

• Hair loss
• Mouth sores
• Loss of appetite or increased appetite
• Nausea and vomiting
• A higher risk of infection (from low white blood cell counts)
• Changes in menstrual cycle (this could be permanent)
• Easy bruising or bleeding (from low blood platelet counts)
• Being very tired (called fatigue, often caused by low red blood cell counts or other reasons)

Most of these side effects go away when treatment is over. For example, your hair will grow back and your blood counts will return to normal. If you have any problems with side effects, be sure to tell your doctor or nurse because there are often ways to help.

Menstrual changes: For younger women, changes in menstrual periods are a common side effect of chemo. Permanent side effects can include early change of life (menopause) and not being able to become pregnant (infertility). But even if the chemo has caused your periods to stop, you may still be able to get pregnant. Getting pregnant while having chemo could lead to birth defects and cause problems with treatment. If you are having sex, you should discuss birth control with your cancer doctor. Women who have completely finished treatment (like chemo) can safely go on to have children, but it's not safe to get pregnant while on treatment. If you are pregnant when you get breast cancer, you still can be treated. Certain chemo drugs can be safely given during the last 2 trimesters of pregnancy. This is discussed in the section, “Treatment of breast cancer during pregnancy.”

Neuropathy: Some drugs used to treat breast cancer can damage nerves. This can sometimes lead to symptoms (mainly in the hands and feet) such as pain, burning or tingling, sensitivity to cold or heat, or weakness. In most cases this goes away once treatment is stopped, but it may last a long time in some women. You can learn more about this in our document Peripheral Neuropathy Caused by Chemotherapy. 

Heart damage: Some of the drugs may cause heart damage if used for a long time or in high doses. Doctors are careful to control the doses of these drugs and watch for signs of problems.

Hand-foot syndrome: Certain chemo drugs can cause problems with the palms of the hands and the soles of the feet. This is called hand-foot syndrome. Early symptoms include numbness, tingling, and redness. If it gets worse, the hands and feet become swollen with discomfort or even pain. The skin may blister, leading to peeling of the skin or even open sores. There is no specific treatment, but these symptoms slowly get better when the drug is stopped or the dose is decreased. The best way to prevent severe hand-foot syndrome is to tell your doctor when early symptoms come up so that the drug dose can be changed.

Chemo brain: Many women who have been treated for breast cancer notice a change in concentration and memory. This is often called “chemo brain.” Although many women link this to chemo, it also has been seen in women who did not get chemo as a part of their treatment. These problems can last a long time, but they are not often severe, and do get better over time. Most women function well after treatment. In studies that have found chemo brain to be a side effect of treatment, the symptoms most often go away in a few years. For more information, see our document, Chemo Brain.

Increased risk of leukemia: Very rarely, years after treatment for breast cancer, certain chemo drugs may lead to a disease called myelodysplastic syndrome or even a cancer called acute myeloid leukemia (AML). But for most women the benefit of treating the breast cancer far outweighs the risk of this rare event.

Feeling unwell or tired: Many women do not feel as healthy after having chemo as they did before. Extreme tiredness, called fatigue, can be another long-lasting problem for women who have had chemo. This may last for many years, but it can be helped. Talk to your doctor if fatigue is a problem for you. You can also get more information in our document Fatigue in People With Cancer.