Breast Cancer Health Center

Breast Cancer and Chemotherapy

What Are the Potential Side Effects of Chemotherapy Drugs?

The specific chemotherapy side effects you will experience depend on the type and amount of medications you are given and how long you will be taking them. The most common temporary side effects include:

• Nausea and vomiting
• Loss of appetite
• Hair loss
• Mouth sores
• Changes in menstrual cycle
• Higher risk of infection (due to decreased white blood cells)
• Bruising or bleeding
• Fatigue

Ask your health care provider about specific side effects you can expect from your specific chemotherapy medicines. Also, discuss with your provider any side effects that are troubling or are difficult to manage.

How Will Chemotherapy Affect My Reproductive Life?

Breast cancer and chemotherapy will undoubtedly cause many changes in your life. One change you may experience from chemotherapy is alterations in your menstrual cycles -- from irregular periods to the signs and symptoms of menopause, the period at which a woman stops menstruating permanently. 

Experts don't fully understand all of chemotherapy's effects on the female reproductive system.

How Does Chemotherapy Trigger Menopause?

During chemotherapy, women may have irregular menstrual cycles or amenorrhea (disappearance of menstrual periods). Some chemotherapy drugs may also cause damage to the ovaries, resulting in menopausal symptoms or early menopause.

Menopause triggered by chemotherapy may be immediate or delayed, permanent or temporary. Unfortunately, there is no way to accurately determine how or when chemotherapy or other cancer treatments will affect your menstrual cycle.

However, menopause is rarely a sudden response to chemotherapy. When treatments begin, some menopausal symptoms may set in. But typically, the symptoms are delayed for several months after treatment is started. This is natural. Menopausal symptoms may last for years after treatment is completed.

The most common symptoms of menopause are hot flashes, emotional changes, vaginal dryness, sexuality changes, and weight gain.

Will My Periods Be Different After Chemotherapy?

Menstrual cycles vary from woman to woman. Some women may experience less frequent cycles than they had prior to chemotherapy. They may skip a period or increase the number of days between periods. Other women may have more frequent periods.

Some women may not experience a change in the length of their menstrual cycles; however, the flow pattern may be different than it was before treatment (the number of days or amount of flow may lessen, or the flow may be heavier). Mixed patterns are also common: some women may have shorter menstrual cycles with heavier bleeding, or infrequent cycles with many days of a very high flow.

Even though periods tend to be irregular around the time of menopause, it is important to be aware of bleeding that is not normal for you. It is very important to call your health care provider if you ever have very heavy bleeding that is accompanied by weakness or dizziness.