Warning over use of MRI scans in breast cancer

The use of magnetic resonance imaging – or MRI scans – on patients who are not suffering from an advanced form of the disease may be

inadvisable, research suggested.

In these scans, strong magnetic fields and radio waves produce a

detailed image of the inside of the breast.

Unlike X-rays, they do not expose the patient to radiation.

But one study of breast cancer patients being considered for non-surgical treatment found a 6 per cent increase in mastectomies – or removals of the breast – in those who had a magnetic resonance mammography.

According to Malcolm Kell, consultant surgeon and senior lecturer at the Eccles breast screening unit at University College Dublin, the devices are so sensitive they are picking up secondary growths better left alone.

Writing in the British Medical Journal, he said that while the scans were extremely useful in monitoring advanced breast cancer and assessing chemotherapy, their use in early stage breast cancer may do more harm than good.

He wrote: "Magnetic resonance mammography identifies occult disease in the breast that may not be visible on other imaging modalities and this may lead to inappropriate treatment decisions."

He concluded: "There is no compelling evidence that this technique should be routinely used in newly diagnosed breast cancer."

In the last decade, MRI or magnetic resonance mammography has become the most favoured type of investigation for high risk patients when combined with mammography and ultrasound, he said.

But Mr Kell wrote: "Its routine use in the management of patients with early stage breast cancer may be unwarranted. We have no evidence to support a clear benefit in this setting."

Instead he suggested the best way to manage early stage breast cancer and reduce the need for unnecessary and invasive surgery was through yearly monitoring and drug treatment, and radiotherapy where necessary.

But cancer charities were sceptical. Breast Cancer Care said it was unlikely that many women would be affected as MRI is not usually used on patients suffering the early stages.

Clinical director Emma Pennery said: "MRI can be useful for looking for recurrence of the disease. It might detect recurrent disease but you don't necessarily know when you do a mastectomy whether leaving it alone would have harmed the patient or not.

"The tumour may be harmless in some women but you can't tell in whom it would be and in whom it wouldn't be.

"Also, if a woman has cancer back in her breast it's not uncommon for her to say 'please take it away'."

Cancer Research UK director Dr Lesley Walker said: "In the UK, doctors routinely use X-ray mammography to help decide how best to treat women with early stage breast cancer, although MRI may be used to monitor women at high risk of inherited breast cancer.

"The mammograms women get through the NHS screening programme are X-rays, rather than MRI scans, which are effective at picking up cancer at an early stage when the disease is often easier to treat."