Worried you may be at risk for high blood pressure? Chances are you take a daily pill to cut down on the chances of heart attack or stroke. Same goes for people concerned about their cholesterol. In fact, studies have shown that preventive medicine is a safe and effective way to combat disease. So why aren’t more women taking drugs that could help them ward off breast cancer?

That’s a question that baffles some scientists, especially given how prevalent and deadly breast cancer can be. In the United States, more than one-hundred and ninety-two thousand women were diagnosed with breast cancer in 2009, and about forty-thousand women died from the disease.

A number of studies have shown that two widely available drugs, tamoxifen and raloxifene, can cut the risk of developing breast cancer in half for women believed to be at risk for the disease. Yet some women are reluctant to take the drugs. In one recent study, six-hundred and thirty two women who were considered at high risk of developing breast cancer over the next five years were given a thorough briefing about the benefits and drawbacks of tamoxifen. Only six percent of the participants said they would take it. Three months later, only one percent had actually started.

Granted, neither drug is perfectly effective. Both carry some risk of side effects, particularly increased risk of stroke, vaginal dryness and hot flashes. And some women said they didn’t want to take the medicine because they believed there was a stigma attached to taking a cancer drug.

For now, the scientists recommend that women talk to their doctors about their risk of breast cancer and the potential benefits of these drugs. Because for some, the pros might well outweigh the cons.