Statins could be valuable addition to breast cancer treatment

Scientists have raised the possibility of using statins, cholesterol reducing drugs, to stop some breast cancers returning.

The most common form of breast cancer in the UK is oestrogen receptor (ER) positive which uses oestrogen to grow. Hormone therapy drugs such as ‘tamoxifen’ and aromatase inhibitors cut off the supply of oestrogen, reducing the chances the cancer will return after surgery. Nevertheless, about a quarter of those cancers recur.

A study published in the journal of Breast Cancer Research shows that ER-positive breast cancers can produce a molecule (known as 25-HC) made from cholesterol which mimics oestrogen and can encourage cancer cells to continue to grow.  When scientists interfered with the production of 25-HC they found it slowed the cancer cells’ growth by between 30% and 50%.

Dr Lesley-Ann Martin at the Institute of Cancer Research in London, where the research has been carried out, 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 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.”

Delyth Morgan, Chief Executive of Breast Cancer Now, which funded the research said: “This is a really crucial discovery. Far too many women have to deal with the potentially devastating consequences of their breast cancer coming back and this research presents an important opportunity to improve the effectiveness of today’s most commonly used treatments.

“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.”