How to prevent breast cancer with chemoprevention

A healthy living blog from Marshfield Clinic Health System

How to prevent breast cancer with chemoprevention

Oct 9, 2023

Getting a mammogram is the most common way to catch breast cancer. However if you have increased risk for the disease, chemoprevention is a relatively new process that actually works to prevent breast cancer in the first place.

Woman on her phone in the kitchen - Can you prevent breast cancer? Chemoprevention — Chemoprevention is a relatively new process that works to prevent breast cancer.

Chemoprevention involves taking a medication that binds estrogen receptors to reduce estrogen for five years. This reduces your chance of developing breast cancer during that time by up to 50 percent.

“For patients who have a higher risk than the general population to develop breast cancer, we try to prevent it. One way of preventing it is to give a medication to reduce the future development of cancer,” said Dr. Patcharin Tanawattanacharoen, an oncologist/hematologist with Marshfield Clinic Health System.

Despite the name, chemoprevention is not actually chemotherapy. It does not cause hair loss or other common side effects of receiving chemotherapy.

Increased risk needed for chemoprevention

To take chemoprevention medications, you need to have more than a 1.7 percent chance of developing breast cancer in the next five years.

Your primary care provider uses a special formula to determine if you have risks that make you eligible.

Risk factors include:

Family history
Personal history of breast biopsy
Personal history of atypical breast pathology

If your primary care provider finds you to be at an increased risk for breast cancer in the next five years, they should refer you to a High Risk Breast Clinic.

Specifics about chemoprevention

Chemoprevention uses two different types of medications:

Tamoxifen: For pre- and post-menopausal women
Aromatase inhibitors: For post-menopausal women

Both options may have a few side effects, but Dr. Tanawattanacharoen said the benefits usually outweigh the risks.

“If we determine the risk is high enough that there will be a benefit to preventing breast cancer development, then we offer these medications to reduce the risk,” Dr. Tanawattanacharoen said.

Before participating in chemoprevention, you must be 35 years or older and cannot be pregnant. These medications can be harmful to a developing fetus.

While chemoprevention can reduce your risk of developing breast cancer, Dr. Tanawattanacharoen said you should continue to have a regular mammogram after age 40. Younger women with a family history or other risk factors should consult their doctor.

Dr. Tanawattanacharoen does not recommend chemoprevention when the risk for developing breast cancer is too high. One example is if through genetic testing you are found to be BRCA1 or BRCA2 positive. This increased risk would be too large, so she would instead recommend a more proactive approach.

For more information about chemoprevention or to find out if you are at an increased risk of breast cancer, please talk to your doctor.