Vancouver radiologist Dr. Ian Gardiner gave a timely presentation to medical professionals in B.C. via video link last week: “Screening Mammography: Is it still controversial in 2012?”
Well, yes it is.
Vancouver radiologist Dr. Ian Gardiner gave a timely presentation to medical professionals in B.C. via video link last week: “Screening Mammography: Is it still controversial in 2012?”
Well, yes it is. The Lancet published a review this week saying screening leads to over-diagnosis and treatment of tumours that, if left alone, would never have threatened women’s lives because they were very slow-growing.
As Gardiner, an expert in breast imaging, pointed out in his presentation (still available online through the link above), it’s true that doctors still can’t tell the difference between a fast-growing and slow-growing tumour. But that’s beside the point, in his opinion. What’s clear is that there have been decreases in deaths from breast cancers in countries that invite women to have free, annual mammograms.
This is also one of the main findings of The Lancet article. It goes on to say, however: “For every 10,000 UK women aged 50 years invited to screening for the next 20 years, 43 deaths from breast cancer would be prevented and 129 cases of breast cancer, invasive and non-invasive, would be over-diagnosed; that is one breast cancer death prevented for about every three over-diagnosed cases identified and treated.”
For Gardiner, that’s a small price worth paying, both financially and in terms of saving lives. He calculates that each mammogram in B.C. costs the system about $75. Is not knowing really better? he asks. Do women want to be in the dark about their health? Some participants in the debate following his presentation suggested that more extensive counselling of women before a mammogram might be helpful to explain the risk of over-diagnosis.
Before The Lancet article, a Danish researcher Peter Gotzsche wrote a much-publicized review for the Cochrane Library in 2011 that reached a similar conclusion about over-diagnosis and treatment.
Later that year, the Canadian Medical Association Journal published new guidelines recommending no annual screening for low-risk women under 50 and mammograms every two to three years for women after that.
Gardiner says he disagrees and suggested his own view of the future should women decide to reduce or stop regular mammograms: there will be fewer breast cancers diagnosed in the next two years because fewer women go for screening. Then women and doctors will begin finding larger tumours that are detectable with touch rather than the X-ray imaging used in mammography that spots tiny abnormalities. Finally, after five to seven years, there will be an increase in the number of deaths from breast cancer in countries that had previously seen falling rates.
His advice? Begin annual screening at 40 and don’t stop.