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. In some cases, 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.

Several chemotherapy drugs can affect nerve endings in your hands and feet, leading to numbness, pain, burning or tingling, sensitivity to cold or heat, or weakness in your extremities. 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.

"Chemo brain," "chemo fog" and "chemo memory" are terms used to describe controversial and little-understood short-term memory and concentration problems that may occur after chemotherapy. In most cases, these problems go away within a year of completion of the chemotherapy.

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

Your doctor can prescribe drugs to help reduce nausea and vomiting caused by chemotherapy. You can also talk with your doctor and chemotherapy nurse about measures you can take to minimize side effects.

If chemotherapy damages your infection-fighting blood cells, your doctor may adjust your doses or add medications that help your bone marrow to recover more quickly.

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 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. But because the effects of chemotherapy are dangerous to the fetus, talk with your doctor about birth control options before treatment begins.

  • Osteopenia and osteoporosis. 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.
  • Leukemia. Rarely, chemotherapy for breast cancer can trigger a secondary cancer, such as cancer of the blood cells (leukemia), several years after the chemotherapy was 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 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 cancer-survivor hotline, support group or online community.

Nov. 15, 2017
References
  1. Chemotherapy for breast cancer. American Cancer Society. http://www.cancer.org/cancer/breastcancer/detailedguide/breast-cancer-treating-chemotherapy. Accessed July 5, 2017.
  2. Breast cancer. Fort Washington, Pa.: National Comprehensive Cancer Network. http://www.nccn.org/professionals/physician_gls/f_guidelines.asp. Accessed June 28, 2017.
  3. Sikov WM. General principles of neoadjuvant therapy for breast cancer. https://www.uptodate.com/content/search.
  4. What to expect when having chemotherapy. Cancer.Net. http://www.cancer.net/navigating-cancer-care/how-cancer-treated/chemotherapy/what-expect-when-having-chemotherapy. Accessed July 5, 2017.
  5. What you need to know about breast cancer. National Cancer Institute. https://www.cancer.gov/publications/patient-education/wyntk-breast-cancer. Accessed June 29, 2017.
  6. Taghian A, et al. Overview of the treatment of newly diagnosed, non-metastatic breast cancer. https://www.uptodate.com/content/search. Accessed July 5, 2017.
  7. Fertility concerns and preservation for women. Cancer.Net. http://www.cancer.net/navigating-cancer-care/dating-sex-and-reproduction/fertility-concerns-and-preservation-women. Accessed Aug. 23, 2017.
  8. Chemotherapy. National Cancer Institute. http://www.cancer.gov/about-cancer/treatment/types/chemotherapy. Accessed July 5, 2017.
  9. Long-term side effects of cancer treatment. Cancer.Net. http://www.cancer.net/survivorship/long-term-side-effects-cancer-treatment. Accessed July 5, 2017.
  10. Sikov WM. Neoadjuvant therapy for patients with HER2-positive breast cancer. https://www.uptodate.com/content/search.
  11. Hartmann LC, et al. Treating invasive breast cancer. In: the Mayo Clinic Breast Cancer Book. Boston, Mass.: Da Capo Press; 2012.
  12. Barbara Woodard Lips Patient Education Center. Breast Cancer Handbook. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2012.
  13. Nangia J, et al. Effect of a scalp cooling device on alopecia in women undergoing chemotherapy for breast cancer. The SCALP randomized clinical trial. JAMA. 2017;317:596.
  14. Boland TA. Financial Planning and Analysis. Mayo Clinic, Rochester, Minn. July 5, 2017.
  15. Alvaro Moreno A (expert opinion). Mayo Clinic, Jacksonville, Fla. July 17, 2017.
  16. Melisko ME, et al. Objective assessment of physical activity during chemotherapy for breast cancer. Journal of Clinical Oncology. In press.
  17. Goetz MP, et al. Tumor sequencing and patient-derived xenografts in the neoadjuvant treatment of breast cancer. Journal of the National Cancer Institute. 2017;109:djw306.
  18. Von Roemeling C, et al. Breaking down the barriers to precision cancer nanomedicine. Trends in Biotechnology. 2017;35:159.
  19. Breast cancer prevention — Patient version (PDQ). National Cancer Institute. https://www.cancer.gov/types/breast/hp/breast-prevention-pdq. Accessed July 11, 2017.
  20. AskMayoExpert. Breast cancer. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2017.