Mammography Questioned Again, British Program Under Review

Zosia Chustecka

October 25, 2011

October 25, 2011 — Once again, the benefits and harms of mammography are being discussed in public forums, in a major medical journal, and in an entire country, now that the national breast screening program in the United Kingdom is officially under review.

In an analysis published online October 24 in the Archives of Internal Medicine, 2 American academics focus on the claim that "mammography saves lives." This powerful slogan, and the story it doesn't tell, was discussed in detail in a special Medscape Medical News report last year. The new analysis, carried out by Gilbert Welch, MD, MPH, and Brittney Frankel, from the Dartmouth Institute for Health Policy and Clinical Practice, Hanover, New Hampshire, addresses this specific claim once again.

"Most women with screen-detected breast cancer have not had their lives saved by screening," the authors conclude. "They are instead diagnosed early (with no effect on their mortality) or overdiagnosed."

Questions about mammography have been circulating for some time across the Atlantic, where the British national breast screening program is currently being reviewed. The national program — which offers mammography every 3 years to women 47 to 73 years of age — has previously come under attack for not representing the harms of screening as adequately as the benefits. Some of these concerns, as well as many others, have resurfaced in a letter published online October 25 in BMJ from Susan Bewley, MB BS, MRCOG, professor of complex obstetrics, division of women's health, at King's College London, United Kingdom. A reply from the UK cancer tsar Mike Richards, CBE, MD, FRCP, DSc(Hon), national clinical director of cancer at the Department of Health, London, accompanies the letter.

"The ongoing controversy should, if at all possible, be resolved," Dr. Richards writes.

An independent review of the research evidence for breast cancer screening (including both randomized controlled and observational studies) was initiated a few weeks ago, Dr. Richards writes.

He will be leading the review (Dr. Richards was formerly a consultant medical oncologist at Guy's Hospital, specializing in breast cancer), along with Harpal Kumar, MA, MEng, MBA, chief executive officer at Cancer Research UK. They are trying to find "independent advisers who have never previously published on the topic of breast cancer screening," he notes.

Once the review is complete, the evidence will be presented at a workshop hosted by Cancer Research UK; experts from both sides of the argument will be invited.

In addition, the information issued to the public, such as the leaflets sent out with the invitation to screening, is also under review, Dr. Richards notes. This is being carried out for all the cancer screening programs currently operating in the United Kingdom (including colorectal and cervical cancer) — but the breast cancer leaflet will be the first to be revised, he notes. Again, this review will be undertaken by an independent team, and it will take into account current thinking on how to synthesize information on the benefits and harms to offer an informed choice, he explains.

Saving Lives

The British national program is based on advice from the independent Advisory Committee on Breast Cancer Screening. This committee concludes that "breast screening saves lives and...the benefits considerably outweigh the harms," Dr. Richards notes.

This is in line with the stance taken by the World Health Organization's International Agency for Research on Cancer, he notes.

However, it is this central message — that screening saves lives — that is questioned in the analysis by Dr. Welch and Ms. Frankel. They address the "enthusiasm for screening" and the cancer survivor stories — particularly those of celebrities — that have created a presumption among the general public that every survivor whose cancer was detected by screening has had her "life saved" by screening.

"Our analysis suggests this is an exaggeration," they write, adding: "In fact, a woman with screen-detected cancer is considerably more likely not to have benefited from screening."

An accompanying commentary points out that all preventive healthcare services, not only breast cancer screening, can result in tremendous benefits but can also cause harms such as overdiagnosis and overtreatment. The piece is authored by Timothy Wilt, MD, MPH, and Melissa Partin, PhD, from the University of Minnesota, Minneapolis. Dr. Wilt is also a member of the US Preventive Services Task Force.

They urge clinicians to be a "reliable source of information" for their patients, and say that the message about any preventive procedure needs to be tailored to the individual. In some circumstances, the message might be negative, with the clinician recommending against a test, they point out.

Arch Intern Med. Published online October 24, 2011. Abstract, Commentary

BMJ. Published online October 25, 2011. Letter, Reply

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