Study links high cholesterol to increased risk of breast cancer

A new study recently presented at the Frontiers in Cardiovascular Biology meeting in Barcelona, Spain, suggests that women who have high cholesterol may be at higher risk of developing breast cancer.

woman checking breast
Using a statistical model, the researchers estimated that women with high cholesterol were 1.64 times more likely to develop breast cancerthan women with normal cholesterollevels.

The research team, led by Dr. Rahul Potluri of the Algorithm for Comorbidities, Associations, Length of Stay and Mortality (ACALM) Study Unit at Aston University School of Medicine in the UK, says their findings indicate that statins – drugs used to reduce levels of low-density lipoprotein, or “bad” cholesterol, in the blood – could be used to prevent breast cancer.

Past research has indicated a link between obesity – which can cause high cholesterol – and increased risk of breast cancer. A 2013 study reported by Medical News Today found that the obesity status of a woman may influence the rate of breast cancer cell growth and tumor size.

The researchers note that a more recent study suggested that cholesterol levels are what feeds this association. But the team wanted to investigate the link further.

Women with high cholesterol ‘1.64 times more likely to develop breast cancer’

To reach their findings, the investigators analyzed information from the ACALM clinical database between 2000 and 2013, which included more than 1 million patients.

Of the 664,159 women in the database, 22,938 had hyperlipidemia, or high cholesterol, and 9,312 had breast cancer. The team found that 530 of the women who had high cholesterol developed breast cancer.

Using a statistical model, the researchers estimated that women with high cholesterol were 1.64 times more likely to develop breast cancer than women with normal cholesterol levels.

The researchers say although their findings are purely observational at this point, they could have important long-term implications for women with high cholesterol.

Dr. Potluri says:

“We found a significant association between having high cholesterol and developing breast cancer that needs to be explored in more depth.

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

According to the American Cancer Society, breast cancer is the second leading cause of death among women in the US. This year alone, approximately 232,670 American women will be diagnosed with invasive breast cancer.

The researchers point out that if their findings are validated through further research, they would like to see whether reducing cholesterol with statins could also lower the risk of breast cancer.

“Statins are cheap, widely available and relatively safe,” says Dr. Potluri. “We are potentially heading towards a clinical trial in 10-15 years to test the effect of statins on the incidence of breast cancer. 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.”

Medical News Today recently reported on a study by researchers from University College London in the UK, which revealed thedevelopment of a simple blood test that could predict how likely a woman is to develop breast cancer.

Advertisements

Cholesterol feeds prostate cancer

Cholesterol feeds prostate cancer  BBC News
Prostate images

Prostate cancer can be a killer

High cholesterol levels accelerate the growth of prostate tumours, research has found.A team from Boston’s Children Hospital also found that cholesterol-lowering statin drugs may inhibit prostate cancer growth.

The findings may help explain why prostate cancer is more common in the West, where diets tend to be high in cholesterol.

Details are published in the Journal of Clinical Investigation.

Our data support the notion that cholesterol-lowering drugs might be effective in prevention of prostate cancer
Dr Michael Freeman

Rates of prostate cancer in rural parts of China and Japan, where low fat diets are the norm, are up to 90% less than in the West.Yet when Eastern men migrate to the West their chances of being diagnosed with prostate cancer increase.

This has led doctors to suspect that environmental factors – such as diet – may play a significant role in the development of the disease.

Mice experiments

The Boston team injected human prostate cancer cells into mice and watched them grow.

When the animals were fed high cholesterol diets, cholesterol was found to accumulate in the outer membranes of tumour cells.

This appeared to alter chemical signalling patterns within the cells.

As a result, they resisted signals telling them to commit suicide and instead continued to proliferate in the uncontrolled fashion seen in cancer.

The increased cholesterol levels did not trigger new cancers in the mice.

But six weeks after the tumour cells were injected, mice on the high-cholesterol diets had twice as many tumours as animals on ordinary diets.

Their tumours were also much larger in size.

When the cells were exposed to the cholesterol-lowering drug simvastatin, cell death increased and tumours stopped proliferating.

But replenishing cell membranes with cholesterol caused the cancer to run out of control again.

Lead researcher Dr Michael Freeman said: “Our study opens up a new paradigm in thinking about how cancer might be controlled pharmacologically by manipulating cholesterol.

“Our data support the notion that cholesterol-lowering drugs – which are widely used and fairly safe – might be effective in prevention of prostate cancer, or as an adjunctive therapy.”

Chris Hiley, of the UK Prostate Cancer Charity, said: “This research is clearly at an early stage, as it was accomplished in mouse cells, not men, but it’s heartening to see a plausible connection made between processes inside cells and the Westernised high fat diet that seem to increase the risk of prostate cancer occurring.

“The results do open up thinking about new drug therapies.

“But there is also a low tech option any man could attempt today.

“Adopt a healthy low cholesterol diet and active lifestyle.

“Cut down on saturated fats, reduce the total amount of fat eaten but eat oily fish, and eat a high fibre diet – with porridge oats, and plenty of fresh fruit and vegetables.”

Every year 27,000 men are diagnosed with prostate cancer and 10,000 men die from it.

Brain tumours feed off cholesterol

Scientists say their finding that most glioblastoma tumours are reliant on cholesterol to survive, opens the door to drugs that could be developed to stop them.

American researchers found that up to 90 per cent of glioblastomas – themselves the most common form of brain cancer – have what they called a “hyperactive signalling pathway” for cholesterol.

This means that their cells become programmed to suck up LDL cholesterol, which further feeds their growth.

Dr Deliang Guo, assistant professor of radiation oncology at the Ohio State University Comprehensive Cancer Centre, and lead author of the study, published in the journal Cancer Discovery, said: “Our research shows that the tumor cells depend on large amounts of cholesterol for growth and survival, and that pharmacologically depriving tumor cells of cholesterol may offer a novel therapeutic strategy to treat glioblastoma.”

Dr. Paul Mischel, professor of pathology at the Jonsson Cancer Centre at the University of California Los Angeles, added: “It potentially offers a strategy for blocking that mechanism and causing specific tumor-cell death without significant toxicity.

“Overall, our findings suggest that the development of drugs to target this pathway may lead to significantly more effective treatments for patients with this lethal form of brain cancer.”

The results came from a laboratory study of cells from human brain tumours, as well as animal experiments.

About 5,000 people are diagnosed with brain cancer every year in Britain, while they cause about 3,600 deaths annually.

Glioblastoma multiforma (GBM) tumours are the most common in adults. They are also the most aggressive and are frequently difficult to treat. Average survival time from diagnosis is 15 months.

Controlling ‘bad cholesterol’ production could prevent growth of tumors, study finds

Several studies have recognized a link between obesity and cancer. Richard Lehner, professor of Pediatrics and investigator at the University of Alberta’s Faculty of Medicine & Dentistry, has taken his research further to understand how tumour cells grow through scavenging very low-density lipoproteins (VLDL) and low-density lipoproteins (LDL), commonly known as the “bad cholesterol”, and what mechanisms can be used to reduce the malignant cells’ growth.

The innovative study, an effort of over 2 years by Lehner’s group in collaboration with Gerald Hoefler and his team (Medical University of Graz, Austria), was published in scientific journal Cell Reports. The data gathered from their experiments suggest a feed-forward loop, in which tumours not only use lipids as “building blocks” to grow, but they can regulate their host’s lipid metabolism to increase production of these lipids.

The “bad cholesterol” binds to LDL receptors in the liver, the organ in charge of degrading it and excreting it from the organism as bile. “Cancer cells need lipids to grow. They can make their own lipids or get more from the host because these cells grow so fast,” explains Lehner. “The tumour signals to the liver: ‘I need more cholesterol for growth’ and the liver is reprogrammed to secrete those lipids.”

One of the key factors for this process are proteins we all have that, in larger quantities, may cause a decrease in the amount of LDL receptors to excrete the cholesterol. The tumour affects these proteins to reduce clearance of cholesterol from the blood, leaving the LDL for cancer to feed off of it.

These findings led Lehner and Hoefler to an interesting hypothesis: minimizing the liver’s production of LDL would deprive a tumour from its constant supply and therefore reduce its possibility of growth. Their experiments in pre-clinical models proved to be successful, confirming lower tumour development with the regulation of the proteins that affect production of VLDL (precursors of LDL) and uptake of LDL by receptors from the liver.

This research received the support of grants from the Canadian Institutes of Health Research (CIHR) and Austrian Science Fund (FWF) and its DK Programme. It was also possible through the Faculty of Medicine & Dentistry’s Lipid Analysis Core Facility, the Women and Children Health Research Institute (WCHRI) and the Canada Foundation for Innovation (CFI).

The next step for Lehner and his team will be to test existing medications that would help in limiting the production of cholesterol on patients undergoing cancer treatment — adding them to their current therapies.

“There are medications approved that we can test”, says Lehner. “They were not developed for cancer, they were manufactured for people with hypercholesterolemia [chronic condition where patients have very high level of cholesterol in their blood], but it will be interesting for us to test them with cancer patients and see if there is improvement.”

Lehner intends to expand the support received and develop these tests locally, including technology and facilities from the institutes and clinics related to the University of Alberta. “The collaboration with Austria was to set the concept of the investigation,” he explains. “We have a great group here, great cancer researchers. We are in good hands to continue.”

Should these potential clinical trials prove to be effective, we could be facing an improved way to help cancer patients: eliminating the tumour, while preventing it from growing at the same time.

Media Contact

Ross Neitz
rneitz@ualberta.ca
780-492-5986
@ualberta_fomd

http://www.med.ualberta.ca