Older women who take popular cholesterol-lowering drugs called statins are not more susceptible to breast cancer as some previous data suggest, and one type of these drugs might even reduce risk of the disease, according to a new University of Pittsburgh study.
"At minimum, our findings suggest that women can now be reassured that they are not increasing their risk of developing breast cancer by taking these drugs," said Pitt epidemiologist Jane Cauley
, the study's lead author.
Prior reports on statin use and breast cancer risk have yielded mixed results, providing no consensus on whether these widely prescribed drugs -- Lipitor and Zocor, for example -- impact women's risk of developing the disease.
"The earlier data were basically on all sides -- increased risk, protective effect, no relationship," Cauley said.
To try to clarify the link between breast cancer and statins, Cauley and her colleagues analyzed seven years of data from more than 156,000 postmenopausal women enrolled in the federally funded Women's Health Initiative.
Of these women, approximately 11,700, or 7.5 percent, took statins, and almost 4,400, or 2.8 percent, developed breast cancer.
In their study appearing in today's issue of the Journal of the National Cancer Institute, the researchers report that they found no significant association between the use of statins overall and breast cancer incidence.
But their results suggest that the type of statin might matter.
Specifically, women who took so-called hydrophobic statins that cannot dissolve readily in water -- such as Zocor, Mevacor and Lescol -- had an 18 percent less chance of developing invasive breast cancer than women who did not take these drugs, the study found.
These results are consistent with recent laboratory studies that show hydrophobic statins might inhibit the growth of cancer.
It is too early, however, for cardiologists to begin choosing cholesterol-lowering drugs based on their potential cancer-preventive effects or to recommend that people at high risk for breast cancer start taking statins for their anti-tumor properties, said Boston University epidemiology professor Lynn Rosenberg, who wasn't involved in the research.
"It does look as if there is any effect of statins at all on cancer it is going to something quite small," Rosenberg said. "But we are early on in the use of these drugs so there is still much to learn."
is planning additional large-scale studies to investigate further the potential impact of statin type on breast cancer risk.
By: Jennifer Bails | Pittsburgh Tribune-Review
May 17, 2006