US panel finds insufficient evidence to support mammographyBMJ 2002; 324 doi: https://doi.org/10.1136/bmj.324.7332.255 (Published 02 February 2002) Cite this as: BMJ 2002;324:255
An independent panel of US medical experts that writes information for the National Cancer Institute's online database (http://www.cancer.gov/) has concluded that there is insufficient evidence to show that mammography prevents deaths from breast cancer.
The panel, known as the PDQ screening and prevention editorial board, is going to rewrite its assessment of mammography for the institute's website in March.
It reached its conclusion after reviewing the work of Ole Olsen and Peter Gçtzsche of the Nordic Cochrane Center in Copenhagen, Denmark.
These investigators reassessed their previous meta-analysis of seven randomised trials of screening mammography (Lancet 2000;355:129) and concluded that screening for breast cancer with mammography was unjustified. They also found that screening led to more aggressive treatment, increasing the number of mastectomies by about 20% (Lancet 2001;358:1340).
An article discussing the controversy surrounding mammography was published in the BMJ the following week (27 October, p 956).
By contrast, the website of the National Cancer Institute, dated 21 November 2000, says: “Several studies have shown that regular screening mammograms can help to decrease the chance of dying from breast cancer. The benefits of regular screening mammograms are greatest for women over age 60. For women in their forties, having mammograms on a regular basis reduces their chance of dying from breast cancer by 16% For women age 50-69, there is strong evidence that screening with mammograms on a regular basis reduces breast cancer deaths by 25% to 30%.”
Dr Donald Berry, a member of the panel and chairman of the department of biostatistics at M D Anderson Cancer Center in Houston, Texas, said that he was aware of the difficulty in questioning an enormous mammography business. “Screening programmes bring in patients,” Dr Berry said.