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Revealed, how breast density is key to cancer

Women are being kept in the dark over the most important clue as to whether they will get breast cancer, leading doctors warned last night.

Breast density is a much more important risk factor even than family history for most people, they say.

Among younger women, four in ten cases of breast cancer can be blamed on high breast density, according to a recent US study.


Revealed, how breast density is key to cancer

X-rays can spot tumours in lowdensity breasts dominated by fatty tissue, left. But glandular tissue in dense breasts, right – now thought to be more prone to cancer – shows up white, making tumours much harder to identify

Lower-density breasts tend to be composed mainly of fat cells, but higher-density breasts have a much higher proportion of glandular tissue.

However, density can be determined only by scanning, and firmness does not necessarily equate to high density.

Under the NHS Breast Screening Programme, women are not routinely told whether or not they have dense breasts.

Last night, leading expert Professor Jack Cuzick said women should be told – and referred for further screening if necessary.

‘There’s a very strong scientific argument that women with uniformly dense breasts need more screening,’ he told The Mail on Sunday. Prof Cuzick said standard x-ray mammography struggled to pick out tumours in women with dense breasts, as both healthy tissue and tumours showed white.

‘The whiteness hides any cancers,’ said Prof Cuzick, director of the Wolfson Institute of Preventive Medicine at Queen Mary University of London.

There’s a very strong scientific argument that women with uniformly dense breasts need more screening 

As a result, those with dense breasts not only have a higher overall chance of developing breast cancer, but also a lower chance of it being picked up by screening.

Prof Cuzick believes doctors have been ‘reluctant’ to tell women about the dangers of high-density breasts because they thought ‘there hasn’t been anything you can do about it’.

‘But there are things you can do about it: you can give these women additional screening and some of them could take preventative drugs like tamoxifen to reduce breast density,’ he said.

Dr Anne Mackie, Public Health England’s director of screening, said: ‘We recently commissioned a review of the evidence around breast density and breast cancer screening.

‘We look forward to the outcome and will consider whether any changes to the programme are required as a result.’