Statins could be used in the treatment of breast cancer after researchers found it may help prevent the disease returning.
While a majority of women with ER-positive breast cancer respond to hormonal therapy, about 12,000 per year see it return.
Researchers at the Institute of Cancer Research in London have discovered that cancer cells in these patients can use cholesterol rather than oestrogen to grow and spread.
Dr Lesley-Ann Martin from the Institute said: “During the course of treatment, ER-positive breast cancers, that are ‘fed’ by oestrogen, often become resistant to standard hormone therapy.
“Our research has demonstrated that these cancer cells can use a cholesterol molecule to mimic oestrogen so that they continue to grow without it.
“This is hugely significant. Testing the patient’s tumour for 25-HC or the enzymes that make it may allow us to predict which patients are likely to develop resistance to hormone therapy, and tailor their treatment accordingly.
“Our study also demonstrates that statins could be a valuable addition to breast cancer treatment, and that this warrants investigation in clinical trials.”
When the experts blocked cholesterol production, proliferation of cancer cells slowed by 30% to 50%.
The findings, published in the journal Breast Cancer Research, have been supported by two studies involving patients.
Baroness Delyth Morgan, chief executive of Breast Cancer Now, said: “This is a really crucial discovery.
“This study breaks new ground in uncovering how some breast cancers continue to survive without oestrogen and suggests that women could benefit from adding statins to standard anti-hormone treatments.
“But this is early research and greater clinical evidence is now needed to understand the potential risks and benefits of this approach.”