We have long known that breasts change with age. It is a perfectly natural process but one that women have been fighting for generations. Gravity always wins in the end, particularly over women with large boobs who have had several pregnancies. Joggers can suffer particularly badly. But whilst this age related sagging might not be desirable from an aesthetic point of view, it does have a very useful property from a medical one. The older you get, the less dense your boobs get and the easier it is to image them for lumps. This is the reason why we don’t offer mammograms to young women. Currently on the NHS screening is offered from the age of 47, and this is not just to do with money. It really is more effective after this age. Young boobs just don’t x-ray well. But now the results of new studies show another property of breast density, but this one is not so good. There is increasing evidence that density is a key factor in breast cancer. Women with more tissue than fat in their breasts are up to five times more at risk because they have more cells. Those involved in the research have suggested that all women should be advised of their breast density, and all should be offered ultrasound scans, to pick up tumours that mammography may have missed. The theory is that denser breasts hide their lumps from x-rays, but may reveal them to ultrasound. Of course since this information has been released the usual loud clamouring has started, demanding that the already overstretched NHS offers this extra screening test to all women.
Our current screening program is great. Mammography lowers breast cancer mortality by 15% to 20%. But if ultrasound can further improve this then surely it should be added to the program too? The problem is that it is very operator dependent, and in multiple trials comparing the accuracy of mammography plus ultrasound to that of mammography alone in women with denser breasts who were at high risk for breast cancer, the addition of ultrasound to mammography did result in detection of additional cases of cancer, but at the expense of a roughly fourfold increase in false-positives. This means that four times as many women would have to undergo an invasive biopsy procedure that they do not need if this method of screening was introduced. This would cause a level of anxiety that may be acceptable in a high-risk population, but certainly would not be in lower-risk patients. An unobtainable number of extra man-hours would also be needed to cope with the increased counselling involved.
Neither can ultrasound consistently detect certain early signs of cancer such as tiny deposits of calcium in the breast that cannot be felt but can be seen on a conventional mammogram. Nor does it have good spatial resolution like mammography, and therefore cannot provide as much detail as a mammogram image.
What is not being publicised is the fact that the combination of mammography and ultrasound still missed one out of every five cancers. So ultrasound is certainly not a silver bullet for breast cancer screening and shouldn’t be hailed as such. Perhaps rather than shouting that women are being denied ‘life saving cancer tests’ we should be a little more measured in our approach and look for ways to improve the uptake of mammography itself. Still too many women do not attend. Also, ensuring all screening programs offer digital imaging, which is more accurate still, may be a better use of time and money, and will avoid creating a cohort of worried and confused women.
Our current screening program is great. Mammography lowers breast cancer mortality by 15% to 20%. But if ultrasound can further improve this then surely it should be added to the program too? The problem is that it is very operator dependent, and in multiple trials comparing the accuracy of mammography plus ultrasound to that of mammography alone in women with denser breasts who were at high risk for breast cancer, the addition of ultrasound to mammography did result in detection of additional cases of cancer, but at the expense of a roughly fourfold increase in false-positives. This means that four times as many women would have to undergo an invasive biopsy procedure that they do not need if this method of screening was introduced. This would cause a level of anxiety that may be acceptable in a high-risk population, but certainly would not be in lower-risk patients. An unobtainable number of extra man-hours would also be needed to cope with the increased counselling involved.
Neither can ultrasound consistently detect certain early signs of cancer such as tiny deposits of calcium in the breast that cannot be felt but can be seen on a conventional mammogram. Nor does it have good spatial resolution like mammography, and therefore cannot provide as much detail as a mammogram image.
What is not being publicised is the fact that the combination of mammography and ultrasound still missed one out of every five cancers. So ultrasound is certainly not a silver bullet for breast cancer screening and shouldn’t be hailed as such. Perhaps rather than shouting that women are being denied ‘life saving cancer tests’ we should be a little more measured in our approach and look for ways to improve the uptake of mammography itself. Still too many women do not attend. Also, ensuring all screening programs offer digital imaging, which is more accurate still, may be a better use of time and money, and will avoid creating a cohort of worried and confused women.
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