Researchers Find Link Between High Cholesterol and Breast Cancer

Study indicates hyperlipidaemia increases risk of breast cancer by 1.64 times.

Having previously been found to increase the risk of heart disease, high cholesterol may also increase the risk of developing breast cancer, according to research presented at the Frontiers in CardioVascular Biology 2014 conference in Barcelona, Spain.

Using a statistical model that examines the link between hyperlipidaemia and breast cancer, researchers found that high cholesterol increases the risk of breast cancer by 1.64 times, according to a press release from the European Society of Cardiology.

"We found that women with high cholesterol had a significantly greater chance of developing breast cancer,” said study lead author Dr. Rahul Potluri in the press release. “This was an observational study so we can't conclude that high cholesterol causes breast cancer but the strength of this association warrants further investigation.”

Following previous population studies that suggested an association between obesity and breast cancer, researchers conducted a study on mice which indicated that through lowering circulating cholesterol or by disrupting its metabolism, breast cancer may be prevented. Subsequently, investigators searched for an association between hyperlipidaemia and breast cancer, according to the release.

The European Society of Cardiology study examined a clinical database with more than 1 million patients across the United Kingdom over a 14-year span. The study included 664,159 women, of which 22,938 had hyperlipidaemia and 9312 had breast cancer. Approximately 530 of the women with hyperlipidaemia eventually developed breast cancer.

While the results of the observational study did not conclude that high cholesterol causes breast cancer, the researchers noted that the strength of the association should lead to further investigation.

“Caution is needed when interpreting our results because while we had a large study population, our analysis was retrospective and observational with inherent limitations,” Dr. Potluri added. “That said, the findings are exciting and further research in this field may have a big impact on patients several years down the line.”

Should future studies validate the connection between high cholesterol and breast cancer, researchers suggest the next step would be a trial examining whether lowering cholesterol with statins could reduce the risk of developing cancer.

"Statins are cheap, widely available and relatively safe. We are potentially heading towards a clinical trial in 10-15 years to test the effect of statins on the incidence of breast cancer,” Dr. Potluri concluded. “If such a trial is successful, statins may have a role in the prevention of breast cancer especially in high risk groups, such as women with high cholesterol."