Aug. 11 : Magnetic resonance imaging (MRI) is substantially more accurate than mammography in diagnosing very early stages of breast cancer, according to a new study published in the journal Lancet.

So far, MRI has been considered to be unsuitable for the detection of ductal carcinoma in situ (DCIS), the most common type of non-invasive breast cancer. Researchers at the University of Bonn have, however, now come up with evidence to the contrary.

Professor Christiane Kuhl and her colleagues examined more than 7319 women with both methods in the past five years. As many as 168 women were detected with early forms of breast cancer, 152 of whom were found using MRI, and 93 with mammography.

“Using mammography only 93 cases of DCIS could be seen, compared with 153 cases detected by MRT. And not only that: it was above all the particularly aggressive high-grade DCIS which were especially reliably picked up using MRI, but especially difficult to detect using mammography,” said the Bonn radiologist, Professor Christiane Kuhl.

Breast cancer forms in the cells which line the inside walls of the milk ducts. It initially remains in the milk duct, and is called DCIS. At this stage it behaves like a benign disease, which can be treated successfully by operating on it.

But when the tumour grows out of the milk ducts into the breast’s glandular tissue, it can spread via blood and lymph vessels in the body.

“If we find DCIS and remove it we can prevent the formation of ‘real’ breast cancer. That way we prevent the development of a disease that is often life-threatening,” the Bonn radiologist, Professor Kuhl, explains.

It has been known for a long time that MRI is superior to mammography as far as the diagnosis of invasive breast cancer is concerned. However, the search for DCIS to date has been the preserve of mammography.

Mammography it highlights small calcifications that form in the milk ducts affected but MRI fails to reveal such depositions, which is why it was hitherto seen as unsuited for detecting DCIS.

But the new results achieved by the Bonn researchers confounded this textbook wisdom.

“Our study demolishes a whole series of textbook dogmas. Firstly, it was always said that MRT was not able to find early stages of breast cancer in the milk ducts. As our results show, the opposite is true. MRT is far more sensitive than mammography,” Prof. Kuhl said.

“The second prejudice is that MRT often leads to ‘false positives’, i.e. often causes ‘false alarms’. ‘Among our patients that was even less the case with MRI than with mammography,” she emphasised.

She also hit out at the notion that MRI was only necessary for early detection of breast cancer in women with an increased risk of breast cancer.

“The conclusion of the Bonn research team is that MRI can improve the diagnosis of very early stages of breast cancer significantly, not simply with high-risk groups, but with all women,” said Prof. Kuhl.

She, however, said that she did not want the new findings to be used as an argument against current mammography screening programmes. (ANI)