Women with breast cancer who take tamoxifen are less likely to have a heart attack than women with other types of cancer who are not taking the drug, according to a new report.

Dr. Susan S. Jick and colleagues, from the Boston University School of Medicine, say their findings suggest that tamoxifen may protect against the development of heart disease.

The researchers note in the medical journal Cancer that treatment with tamoxifen is known to have a beneficial effect on cholesterol levels and other heart disease risk factors, but it was unclear if it actually reduced the likelihood of developing heart disease.

To investigate, Jick’s team studied women with tamoxifen-treated breast cancer or with bladder, colorectal, or skin cancer. The study focused on 151 patients who had experienced a heart attack of heart-related chest pain and a “control” group of 585 similar patients who had not had heart problems.

The investigators found that tamoxifen users were 60 percent less likely than non-users to experience a heart attack or angina. Moreover, the likelihood decreased as the tamoxifen dose and duration of use increased.

The overall analysis suggests that taking tamoxifen is “cardioprotective,” they conclude.

SOURCE: Cancer, March 15, 2005.