Researchers hope that one day, taking a pill to prevent breast cancer will be as routine as taking cholesterol medicine to prevent heart disease.

“One day is today. We know how to do that already,” professor Jack Cuzick told LifeZette.

The problem, to him, is this: “It is not being used.”

Cuzick, from the Queen Mary University of London, is co-author of an international study that looked at more than 21,000 women of all ages who are at high risk for breast cancer. The study’s meta-analysis found that 5 out of 6 women rejected drugs like tamoxifen, which could reduce their chance of getting breast cancer by 50 percent. The study was released this week to coincide with the 2015 San Antonio Breast Cancer Symposium.

“It’s the first real cancer in which we think we can do a lot more about preventing disease in high-risk women with drug therapy,” he said. 

The study, funded by Cancer Research UK, found that just 1 in 6 women at higher risk overall chose to take the five-year course of medication.

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“Understandably women are hesitant, often because of the anticipated side effects,” professor Sam Smith, co-author of the study, told LifeZette. “But many factors are involved.”

A quick check of the blogosphere will tell you that tamoxifen has a reputation for undesirable side effects such as weight gain. It’s an undeserved reputation, though, according to Cuzick.

“That’s a classic example of something that’s gone completely wrong,” Cuzick told LifeZette. “It’s not true.”

“It’s the first real cancer that we think we can do a lot more about preventing disease in high-risk women with drug therapy.”

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There is, however, the potential for side effects other than weight gain — things like menopausal symptoms, endometrial cancer and blood clots, Cuzick said. Those side effects are not universal and often rare, he added.

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“Concerns about side effects have been very much overstated for tamoxifen in breast cancer prevention, and it’s had a very negative effect,” Cuzick said.

Other research shows that high-risk patients and even their doctors aren’t aware of the potential value of tamoxifen, Cuzick said.

For third-generation breast cancer survivor Angela Banker, 36, the results of the UK study are not a big surprise. She didn’t even know tamoxifen was available prior to her diagnosis.

“I was never provided the option for preventive medication,” she told LifeZette from her home in Wenatchee, Washington. “It wasn’t on the table.”

Banker was diagnosed at age 33 and is currently taking tamoxifen to reduce the chance her cancer will come back. Though her side effects are minimal, she doubts she would have taken the drug had she known about it prior to her diagnosis. It would have meant putting off having a child, since women shouldn’t get pregnant while taking the drug.

For her, taking tamoxifen eventually meant giving up on the dream of having more than one child.

“Once I got this drug, it was like, OK, there goes our two-child family,” she said.

For diagnostic breast specialist Dr. Dawn Mussallem of the Mayo Clinic Center for Breast Health in Jacksonville, Florida, the study emphasizes that doctors must have a better opportunity to communicate with their patients.

“Today, many physicians have very limited time to discuss prevention with patients, in part because the system is crowded with treating what has already occurred,” Mussallem told LifeZette. “This is why I love what I do. I get to help women prevent cancer from ever occurring.”

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When it comes to potential side effects of drugs like tamoxifen and raloxifene, Mussallem said treating the whole patient is crucial. Her patients at Mayo have the opportunity to learn about restorative yoga and stress management. The breast center works closely with patients to encourage healthy eating, exercise, no tobacco use and limited alcohol.

Study author Smith told LifeZette that educating primary care physicians is a big part of preventing breast cancer with drug therapy.

“We should be looking to educate clinicians to ensure they are equipped to have these conversations with patients,” he said.

The new study is published in the Annals of Oncology.