Women with high cholesterol levels may have an increased risk of developing breast cancer, a new study involving over one million patients indicates.

According to UK researchers, recent studies have suggested a link between obesity and breast cancer. A study in mice carried out last year indicated that this may be due to cholesterol levels.

"We have a general principle that obesity is linked to breast cancer and a study in mice suggested that this may be because of cholesterol. We decided to investigate whether there was any association between hyperlipidaemia, which is high cholesterol essentially, and breast cancer," noted the study's lead author, Dr Rahul Potluri, of Aston University in Birmingham.

The researchers analysed data relating to over one million patients in the UK between 2000 and 2013. Almost 650,000 of these were women, almost 23,000 had hyperlipidaemia and over 9,300 had breast cancer.

"We found that women with high cholesterol had a significantly greater chance of developing breast cancer. 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," Dr Potluri said.

He pointed out that if this connection between cholesterol and breast cancer is confirmed, ‘the next step would be to see if lowering cholesterol with statins can reduce the risk of developing cancer'. However, he acknowledged that ‘significant time and research is needed before this idea can be tested'.

"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. 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," he said.

Dr Potluri insisted that these findings are ‘promising'.

"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...but the findings are exciting and further research in this field may have a big impact on patients several years down the line," he added.

Details of these findings were presented at the Frontiers in CardioVascular Biology (FCVB) 2014 conference in Barcelona, Spain and are published in the journal, Science.