US researchers suggest there is an underlying mechanism that affects both cancer and low LDL (so-called “bad”) cholesterol, because they found low LDL cholesterol in people with no history of taking drugs to lower their cholesterol precedes cancer risk by decades.

Lead investigator Dr Paul Michael Lavigne, of Tufts Medical Center in Boston, presented the findings, which are based on new data from the Framingham Heart Study (FHS) offspring cohort, at the American College of Cardiology’s 61st Annual Scientific Session in Chicago on Sunday.

The benefits of using cholesterol-lowering drugs to prevent heart disease are well established. However, studies of these drugs have suggested there could be a link between low levels of low-density lipoprotein cholesterol (LDL-C) and cancer risk.

Still, what is not clear from those studies, is whether the link is because of the drugs, or in spite of them.

This new investigation by Lavigne and colleagues, is the first to try and untangle the problem: it looks at the relationship between low LDL-C and cancer risk over a long time in patients with no history of using cholesterol-lowering drugs.

Lavigne said in a statement:

“There has been some debate as to whether or not medications used to lower cholesterol may contribute to cancer, but the evidence so far tells us that the drugs themselves do not increase the risk of cancer.”

He said they wanted to “take those medications out of the equation”, and just study the link between cancer and low LDL-C in people who had never taken statins or other cholesterol-lowering drugs.

For their matched case control study, Lavigne and colleagues compared 201 participants with cancer and 402 controls who were cancer free.

Cancer cases and controls were matched by age, gender, tobacco use, blood pressure, body mass index, diabetes, and other factors.

Neither the participants with cancer nor the controls had any history of taking cholesterol-lowering medication.

The researchers assessed the trend of low LDL-C for an extended period of time prior to cancer diagnosis, using data taken at four points over an average of 18.7 years prior to diagnosis.

The results showed that LDL cholesterol levels were lower in the participants with cancer than their matched controls at each of the data points.

Compared to cancer-free participants, the trend of low LDL-C in those who developed cancer was consistent throughout the period of study.

The results were the same when the researchers took into account levels of high-density lipoprotein (HDL, or “good”) cholesterol.

Lavigne pointed out that these findings do not suggest that having LDL-C inevitably leads to cancer.

And he recommended that people with high LDL-C should follow the current guidelines, including using cholesterol-lowering drugs, to prevent heart disease.

Lavigne said they suspect there is some third factor, an underlying mechanism behind both cancer and low LDL-C.

But for now, all they can be sure of is there is a link between cancer and low LDL-C, and it exists for a long time before cancer diagnosis.

These findings highlight the need for further studies into the link and its underlying mechanism, he added.

Written by Catharine Paddock PhD