Breast cancer is one of the major ‘ladykillers’ – and so governments want to be seen to do something, not least because it affects half the electorate. For the past 24 years – and at a total cost of £2.3bn - women in the UK over the age of 50 have been invited to have a regular mammogram screening in order to detect early signs of breast cancer.
The genesis of the UK’s mass screening programme was the Forrest report of 1986, headed by Prof Sir Patrick Forrest, who had been commissioned to answer two primary questions: would a mass screening programme benefit women and, if so, which technology should be employed? Forrest’s answers to both were emphatic: mass screening for the over-50s would reduce deaths from breast cancer by a third and with “few harms”, and, to the second, the best technology was x-ray mammography.
Unfortunately, there is no connection between the two answers. Screening might reduce the rate of breast cancer deaths, but mammography isn’t the technology to achieve it.
This started to become apparent just eight years after the mass screening programme was introduced. One of the programme’s guiding lights, Prof Michael Baum, pronounced that he feared mammography was doing more harm than good, and was putting women through the trauma of a ‘false-positive’, when cancer is wrongly detected.
Since then, we have discovered why. Researchers at Southampton University recently revealed that Forrest’s recommendations had been based on limited, and false, data, and had been collated at a time when the concept of a false-positive result was alien to radiologists.
Forrest also asked all the wrong questions about mammography’s competing technology, thermography. Before Forrest, the two were often used in conjunction in order to get the ‘complete picture’: mammography sees mass, thermography sees activity.
As it is, mammography’s harm is far outweighing its benefits – it is seeing cancers that aren’t there, most notably instances of DCIS (ductal carcinoma in situ), which is invariably benign. Worse, it is unable to see fast-growing cancers that are invariably fatal.
Others since have echoed Baum’s concerns, most notably Cochrane researcher Peter Gotzsche, as our Special Report this month explains (http://www.wddty.com/the-great-mammogram-con.html).
But will our government be brave enough to act – or is it politically more expedient to be seen to be doing something, even if it is hopelessly wrong?