What is chemotherapy?

Chemotherapy is a type of cancer therapy that uses drugs to stop or slow the growth of cancer cells. Chemotherapy treatment is usually given as a regimen, a combination of two or more different drugs, in order to target multiple phases of growth and division in the cancer cells.

Who would be offered chemotherapy?

If the risk of your cancer returning after surgery outweighs the risk of the side effects of chemotherapy, you might be offered chemotherapy. Your doctor will take into account all the characteristics of your cancer (size and grade of the tumour, hormone receptor status,  any lymph node involvement, etc.) as well as your personal health history and age in deciding whether to recommend chemotherapy. Sometimes a doctor may request another test called a genomic assay to determine whether you would benefit from having chemotherapy. This test examines the activity of genes within breast tumour tissue to see how active they are. Knowing the activity of certain genes can help estimate the risk of a breast cancer recurrence.

The Oncotype DX Breast Cancer Assay is a commonly used genomic assay test. It can be used for women with early stage hormone receptor positive breast cancer to predict the  likelihood of breast cancer returning. The result of the test is given as a number between 0 and 100, known as the recurrence score. A lower score means the cancer has a lower chance of returning. A higher score means that there is a higher chance of the cancer returning and that you would benefit from chemotherapy. The Oncotype DX test is currently publicly funded for qualified patients in British Columbia, Alberta, Saskatchewan, Ontario, Quebec, Nova Scotia and Newfoundland.

How and when is chemotherapy given?

Chemotherapy is usually given within three to six weeks after surgery. In some cases, chemotherapy is given before surgery to shrink a tumor if it is quite large, or if lymph node involvement has been detected. This is called neoadjuvant therapy.

Most chemotherapy drugs for breast cancer are given through an intravenous or IV tube, so you will need to go to the hospital or cancer centre to get your treatment. Chemotherapy  is usually given every 2 to 3 weeks. You may have a total of 4 to 8 treatments. Women with metastatic breast cancer may be on a different treatment plan.

I try to make chemotherapy days as positive as possible. I treat myself to a specialty coffee or a fancy soup.That gives me something to look forward to and increases my fluid intake!

What are the common side effects?

Although chemotherapy is intended to kill cancer cells, it also affects normal cells as well, resulting in a number of side effects. Side effects will vary depending on the type and dose  of drug.

Common side effects include:

  • Hair loss
  • Nausea/vomiting
  • Changes in appetite
  • Diarrhea/constipation
  • Dry mouth
  • Mouth sores
  • Tiredness/fatigue
  • Low blood cells

There are drugs and other treatments available to help prevent or control some of the side  effects of chemotherapy. It is important to tell your medical team about any side effects you are experiencing so they can be effectively managed.

Links to more information

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Susan G. Komen for the Cure

Questions to Ask Your Doctor about Breast Cancer Chemotherapy
Susan G. Komen for the Cure

Chemotherapy for Breast Cancer
Cancer Help UK

Chemotherapy and Other Drug Therapies: A Guide for People with Cancer
Canadian Cancer Society


Chemotherapy and You: Support for People with Cancer
National Cancer Institute

Chemotherapy Side Effects
National Cancer Institute

The Scott Hamilton CARES Initiative

Chemotherapy (video)