In the US, women are invited to start mammogram screening from the age of 40, but there's no evidence it is saving lives, says the American Cancer Society. Instead, screening shouldn't start before the age of 45, and even women who are 55 or older need to have a mammogram only every two years, and not annually as currently recommended.
Although early detection makes cancer more treatable, there's no evidence that starting mammograms at the age of 40 is making any difference to survival rates. Worse, mammograms are also detecting cancers that aren't there (false-positives), which can trigger a range of treatments from unnecessary biopsies to surgery to remove lumps or even the whole breast.
Mammograms are detecting just five cancers in every 10,000 in women in their 40s and 10 per 10,000 in women in their 50s. This means that 85 per cent of women who die from breast cancer would do so irrespective of mammogram screening.
Other forms of screening, such as genetic risk factors or even manual examination, could be more accurate and helpful. Only women who are at high risk of breast cancer-possibly because of family history or faulty genes-should have annual mammograms, and possibly starting at the age of 40 or even earlier.
The American Cancer Society's new guidelines are more in line with those of the US Preventive Services Task Force, another highly influential body in determining public health policy. The task force says that screening is unnecessary for women at average risk of breast cancer between the ages of 45 and 49, and only screening every two years for women aged between 50 and 54.
(Source: Journal of the American Medical Association, 2015; 314: 1599-1614)