Breast Cancer Drugs Not Without Their Own Risk

By Rachel Stockton

They say that knowledge is power, which is true for the most part.  However, there is a downside with having knowledge of certain information, as it forces us to make choices that are difficult.   For example, now that researchers have determined the genetic mutation that causes familial breast cancer in pre-menopausal women, those who have the gene must consider some of their options, which aren’t without their own set of problems.

After a woman learns she is at a greater risk for breast cancer, there are two or three difficult courses of action she and her doctor must consider. The first one is to decide whether or not to have an elective, double mastectomy to mitigate that risk.

And, if that decision wasn’t gut wrenching enough, an at risk female must decide whether or not to take raloxifene or tamoxifen, two drugs approved to reduce the risk of breast cancer.  They’ve both proven their efficacy; they can reduce a woman’s risk of developing invasive breast cancer by up to half.

According to the journal Annals of Internal Medicine, both drugs carry certain risks that a woman may decide outweigh the benefits.  Several clinical trials have revealed that of every 1000 women who take the drugs, 7-10 fewer of them will get cancer.

On the flip side, both drugs carry a significant risk of blood clots, especially tamoxifen.  For every 1000 women who take it, there will be 4-7 additional cases of blood clots.  Tamoxifen also increases the risk of endometrial cancer and cataracts.

Finally, to further muddy the waters for a woman trying to make an informed decision, the Federal Trade Commission issued a Facts for Consumers bulletin in 2006 that states that “having a particular gene doesn’t necessarily mean that a disease will develop; not having a particular gene doesn’t necessarily mean that the disease will not.”

When it comes to breast cancer, it seems clear that the more we learn, the more difficult our decisions become.