Women are reluctant to take tamoxifen to help prevent cancer, according to the results of a study published in Cancer Epidemiology, Biomarkers & Prevention (February 2010;19[2]:443-446).

Tamoxifen can reduce the risk of developing breast cancer in women who are at increased risk for developing the disease, say the authors in background information accompanying the study results.

To determine the number of women aged 40-79 who were taking tamoxifen for the prevention of breast cancer, lead author Erika A. Waters, PhD, MPH, assistant professor at Washington University School of Medicine in St. Louis, and colleagues at the National Cancer Institute collected data from surveys of more than 10,000 women for each year between 2000 and 2005.

Researchers found that the prevalence of tamoxifen use among the women surveyed was 0.2% in 2000 and 0.08% in 2005. “Our results indicated that very few women were using tamoxifen to prevent cancer,” stated Dr Waters. “However, we don’t know exactly why.”

The authors suggest that low prevalence of tamoxifen use may be linked to the side effects of the medication, which may include hot flashes, sexual complications, uterine cancer, blood clots, and cataracts. Another possible explanation given by the authors is that physicians may be unaware of the drug’s availability, physicians are reluctant to prescribe it, patients are reluctant to take it, lack of patient or physician education about the drug, or skepticism about whether the benefits outweigh the risks.

“The decision to use a drug like tamoxifen in women at high-risk for, but who do not yet have a diagnosis of, breast cancer is not easy. It is dependent upon the women’s personal choice, which can be influenced by many factors, not just her medical eligibility. There is no right answer,” said Dr Waters.