Chemoprevention: Lowering the Chance of Breast Cancer

In the fight against breast cancer, prevention has become as important as finding a cure or prolonging survival ― perhaps more so. Baptist Health’s Miami Cancer Institute is leading the effort to reduce breast cancer in women at risk by taking part in a clinical trial to better educate women on chemoprevention ― medications designed to stop cancer from developing.

The Southwest Oncology Group study, called Making Informed Choices on Incorporating Chemoprevention Into Care (MiCHOICE), is for women ages 35-74 who have no history of cancer themselves, but have been diagnosed with atypical hyperplasia or lobular carcinoma in situ (abnormal cells in the breast that can become cancerous). The national study hopes to determine whether patients, when provided with information and the pros and cons of taking chemoprevention medications, may feel more confident about their decision to take or not take the drugs for their specific risk level and medical history.

Ana Cristina Sandoval, M.D., breast medical oncologist with Miami Cancer Institute.

“These medications have been FDA-approved, have been around for more than 20 years and have been proven to decrease breast cancer risk by 50 to 60 percent,” says Ana Cristina Sandoval, M.D., the Miami Cancer Institute breast medical oncologist who is the study’s principal investigator. “Even though about 15 percent of U.S. women could benefit from chemoprevention, only about 5 to 15 percent of women who are offered chemoprevention agree to take the medication. If we can increase understanding and awareness so that more people with risk factors take these preventive measures, we can decrease breast cancer incidence.”

One in eight American women today will develop breast cancer, according to statistics from the American Cancer Society. The odds increase significantly for those with risk factors.

At the Breast Cancer Prevention Clinic at Miami Cancer Institute, a multidisciplinary team led by Jane Mendez, M.D., chief of breast surgery, works with those who have a number of breast cancer risks. They include known breast cancer genetic mutations, a strong family history of breast cancer, a breast cancer risk of greater than 20 percent as calculated by predictive medical models and underlying high-risk conditions.

Clinic patients may receive additional and frequent breast imaging tests and surveillance, genetic education and counseling, individualized breast health plans and lifestyle modification recommendations. Among those are exercise and diet and lifestyle changes known to reduce the risk of many cancers.

For some patients, chemoprevention drugs ― the most common are tamoxifen, raloxifene and aromatase inhibitors― are also on the table. The medications are taken, usually daily, in oral pill form, for at least five years.

“As with any medications, there can be side effects,” Dr. Sandoval says. “So it’s important that we choose the best medication for the patient and weigh the pros and cons.” Side effects may include menopause symptoms such as hot flashes, vaginal dryness and weight gain. A patient’s age and medical history are taken into account before prescribing any of the medications. If a patient does experience a side effect, it is often possible to reduce the dose or take the pills less frequently, Dr. Sandoval says.

While the purpose of the MiCHOICE study isn’t to track the long-term outcomes of women taking chemoprevention drugs (other studies do that), it is trying to determine if patients who use the online tool to learn more about the medications feel more confident in their personal decision for or against chemoprevention. A recently published study concluded that the lack of chemoprevention awareness makes it impossible for a woman to make educated decisions about her care. In 2019, after an extensive review of chemoprevention medications, the U.S. Preventive Services Task Force publicly endorsed the move to prescribe the drugs to women at increased risk for breast cancer.

Dr. Sandoval knows that communication is key when she is talking to patients about chemoprevention and she believes the study will help better educate women. “From a patient perspective, it is easy to see that many don’t want to take medications for something they don’t yet have. They don’t have cancer. They feel healthy,” Dr. Sandoval says. “But decreasing a patient’s risk of developing breast cancer by half ― that is a pretty good response.”

If you’ve already been diagnosed with atypical hyperplasia or lobular carcinoma in situ and you have never taken risk-reducing chemoprevention drugs, you can see if you are eligible for the study by calling 786-527-8861. Or, if you have those risk factors or others and you’d like to learn more about the Breast Cancer Prevention Clinic at Miami Cancer Institute, you may make an appointment by calling 954-704-6941.

The Institute also offers other breast cancer clinical trials, including the GLORIA study, which is testing the use of a vaccine to prevent the recurrence of triple negative breast cancer. For information on the GLORIA study and other clinical trials available at Miami Cancer Institute, please visit: https://cancer.baptisthealth.net/miami-cancer-institute/clinical-trials.