MRI scan ‘much more effective’ than mammogram

BREAST cancer would be detected earlier and more effectively with a MRI scan rather than the traditional mammography screening method, according to research published today.

More than 60,000 Irish women are screened for breast cancer each year using digital mammography, a form of X-ray that can detect a tumour. This process costs the Government €28 million a year in funding, through the Breast Check Programme.

A study published in today’s Lancet Medical Journal shows that MRIs — or magnetic scans which do not use X-rays — are a more precise form of screening and can detect breast cancer earlier.

The study of 7,300 women used MRI scans in addition to mammography to search for a pre-invasive form of cancer known as ductal carcinoma in situ (DCIS) which affects the milk ducts in the breast.

Of the 167 women found to have DCIS, 92% were diagnosed by MRI compared with 56% by mammography. The MRI scans were also more effective in spotting aggressive or “high-grade” DCIS.

A total of 98% of such cases were detected with a MRI scan compared with 52% by mammography.

“Almost half of these aggressive cases would therefore have been missed without the MRI scans,” says the report.

The MRI scan was also less likely to produce false positive results, and experts have said the report makes it clear that MRI out-performs mammography in detecting breast tumours.

Commenting on the findings, one of the world’s leading breast cancer experts Dr Emma Pennery said the study extended existing knowledge about the accuracy of MRIs indiagnosing DCIS.

“However, it is unclear as to who exactly will benefit most from MRIs as the study included a mixed population, some attending routine breast screening, some being followed up after breast cancer treatment, or others who had a significant family history of the disease,” she said.