Women with breast cancer treated with the anti-estrogen drug tamoxifen are at significantly less risk of having a heart attack or symptoms of heart stress such as angina, according to a new study. The study, published in the March 15, 2005 issue of CANCER, a peer-reviewed journal of the American Cancer Society, finds the benefit becomes pronounced within two years of therapy and is maintained throughout its use.

Tamoxifen has been shown to reduce the risk of breast cancer recurrence by as much as 50 percent.

In addition, increasing evidence indirectly supports its protective effects on the heart. Studies have shown women taking tamoxifen show reductions in markers of cardiac disease, such as bad cholesterol and homocysteine. However, there is little direct evidence of tamoxifen’s heart protective benefits by way of reduced morbidity or mortality.

To evaluate its hypothesized cardioprotective affects, Brian D. Bradbury, D.Sc., M.A. and a team of investigators from Boston University’s Schools of Medicine and Public Health reviewed the records of 3030 breast cancer patients treated with tamoxifen and 4233 patients with other cancers not treated with tamoxifen.

Women treated with tamoxifen were less likely to develop symptomatic heart disease than those who did not receive tamoxifen. On further analysis current use of tamoxifen was associated with significantly reduced risk of heart disease. Moreover, the reduced heart disease effects were observed in women who had completed less than two years of therapy and continued throughout the duration of the five years of recommended therapy.

The authors conclude, “These data are consistent with the proposition that treatment with tamoxifen for women with breast cancer may additionally lower a woman’s risk of developing ischemic heart disease.”

SOURCE: John Wiley & Sons, Inc.