Statins Don't Affect Breast Cancer Risk

Large study counters previous research on the cholesterol-lowering drugs

MONDAY, Oct. 24, 2005 (HealthDay News) -- Cholesterol-busting statins have no effect on a woman's risk of breast cancer, a new study suggests.

Previous studies have indicated that statins, which include widely used drugs such as Lipitor, Pravachol and Zocor, might slow tumor growth and work with chemotherapy to fight breast cancer.

On the other hand, separate research has indicated that statins might increase the risk of breast cancer.

However, a new study involving nearly 80,000 women finds that statins have no effect on breast cancer one way or the other.

"We found that women who used statins for up to six years had a similar risk for breast cancer as women who did not use statins," said study author A. Heather Eliassen, a research fellow at Brigham and Women's Hospital, in Boston. "It appears that statins neither increase nor decrease the risk of breast cancer," she added.

The report appears in the Oct. 24 issue of the Archives of Internal Medicine.

In their study, Eliassen's team collected data on nearly 80,000 women who participated in the ongoing Nurses' Health Study between 1988 and 2000. During that time, 3,177 cases of invasive breast cancer occurred in the group, including 1,727 cases arising in women who were taking statins. Among both statin users and nonusers, the absolute risk of developing breast cancer was less than 1 percent, the researchers found.

The researchers also found no association between breast cancer risk and the use of other cholesterol-lowering drugs or a woman's individual cholesterol level.

"This is good news," Eliassen said. "Women who are using statins, which are proven beneficial in lowering cholesterol, should not be concerned that the drug might increase their risk for breast cancer."

Eliassen noted that heart disease, not breast cancer, is the major cause of death in women. "Given that heart disease is the leading cause of death among women, at this time, breast cancer need not be a consideration as women and their health-care providers make decisions about statin use," she said.

Another expert had hoped statins might fight breast malignancies.

The findings were "a little disappointing, I must say," said Dr. Carolyn Runowicz, the president-elect of the American Cancer Society and director of the Carole and Ray Neag Comprehensive Cancer Center at the University of Connecticut Health Center.

Runowicz is disappointed the study didn't show a reduction in breast cancer from drugs now used by millions. "With something that is so widely used, and a disease that affects 200,000 women per year, if it did reduce the risk of breast cancer, it would have a significant public health effect," she said.

She noted that another study involving women older than those enrolled in the Nurse's Health Study found that statins did reduce the incidence of breast cancer. "There may be certain subsets of women that will benefit," she said.

Runowicz remains hopeful that statins might still reduce risks for breast cancer in some users. "Maybe a longer duration of statin use, or a different subset of women, might show what other studies have shown," she said.

"I think it's reassuring to women who are taking the drug," Runowicz said. "And I think it leaves the door open for more research."

More information

For more on breast cancer, head to the American Cancer Society.

SOURCES: A. Heather Eliassen, Sc.D., research fellow, Brigham and Women's Hospital, Boston; Carolyn Runowicz, M.D., president-elect, American Cancer Society, and director, Carole and Ray Neag Comprehensive Cancer Center, University of Connecticut Health Center, Farmington; Oct. 24, 2005, Archives of Internal Medicine
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