Risks

Chemotherapy medications travel throughout the body. Side effects depend on the drugs you receive and your reaction to them. Side effects may get worse during the course of treatment. Most side effects are temporary and subside once treatment is finished. Sometimes chemotherapy can have long-term or permanent effects.

Short-term side effects

In the process of targeting fast-growing cancer cells, chemotherapy drugs can also damage other fast-growing healthy cells, such as those in the hair follicles, bone marrow and digestive tract. These side effects often go away after treatment is finished or within a year after completing chemotherapy. In some cases, they may be long lasting.

Common short-term side effects include:

• Hair loss
• Fatigue
• Loss of appetite
• Nausea and vomiting
• Constipation or diarrhea
• Mouth sores
• Skin and nail changes
• Increased risk of developing infection (due to fewer white blood cells that help fight infection)
• Nerve damage (neuropathy)
• Problems with cognitive function that affect memory and concentration, also known as chemo brain

Long-term side effects

Certain chemotherapy drugs for breast cancer can cause long-term side effects, including:

• Infertility. One possible side effect that may not go away is infertility. Some anti-cancer drugs damage the ovaries. This may cause menopause symptoms, such as hot flashes and vaginal dryness. Menstrual periods may become irregular or stop (amenorrhea). If ovulation ceases, pregnancy becomes impossible.

  Depending on your age, chemotherapy may induce a premature permanent menopause. Discuss with your doctor your risk of permanent menopause and its consequences.

  If you continue to menstruate, you may still be able to get pregnant, even during treatment or after treatment is completed. But because the effects of chemotherapy are dangerous to the fetus, talk with your doctor about appropriate birth control options before treatment begins.

• Bone thinning. Women who experience menopause early because of chemotherapy may have a higher risk of the bone-thinning conditions osteopenia and osteoporosis. It's generally recommended that these women have periodic bone density tests and, possibly, treatments to prevent further bone loss.
• Heart damage. Chemotherapy carries a small risk of weakening the heart muscle and causing other heart problems. Certain chemotherapy medications are associated with a higher risk of future heart problems.
• Leukemia. Rarely, chemotherapy for breast cancer can trigger a secondary cancer, such as cancer of the blood cells (leukemia), several years after the chemotherapy is completed.

Other side effects

Feelings of fear, sadness and isolation can compound the physical side effects of chemotherapy, both during and after treatment. During chemotherapy, you have regular contact with and support from oncologists and nurses. Everyone involved is working toward the same goal — completion of treatment with the best possible outcome. When it's over, you can feel as if you're alone, with no one to help you return to normal life or deal with fears of breast cancer recurrence.

Consider talking with a mental health professional or other health care professional who works with people who have cancer. It may also help to talk with someone who has been in the same situation. Connect with others through a hotline, support group or online community for people who have been treated for cancer.