Main Category: Breast Cancer
Article Date: 04 Sep 2011 – 9:00 PDT
Peter C Gøtzsche and Karsten Juhl Jørgensen of the Nordic Cochrane Centre urge for “more honesty” from the NHS BSP (Breast Screening Programme). They believe that harm has been understated, and that information issued to the public has in general been unaffected by “repeated criticism and pivotal research” which has expressed reservations regarding screening benefits and registered considerable over-diagnosis.
Their paper, “The Breast Screening Programme and Misinforming the Public”, is published in the Journal of the Royal Society of Medicine.
The authors say:
“Spokespeople for the Program have stuck to the beliefs about benefit that prevailed 25 years ago and continue to question the issue of over-diagnosis.
Women therefore cannot make an informed choice whether to participate in screening based on the information the Program provides. This must be changed.”
The report explains that information is largely embellished, regarding the lives that have been saved through the screening program.
Professor Peter Gøtzsche, co-author of the paper and Director of the Nordic Cochrane Center, explains:
“The claim that death rates have fallen ‘in part from earlier diagnosis associated with screening’ is astonishingly misleading.
Deaths from breast cancer are falling because treatment is improving. There’s been a similar fall in the age-groups not invited to screening. In this respect, and many others, the Program persists in misinforming the public. It was forced to revise its leaflet inviting women for mammography but the new leaflet and their latest Annual Review continue to repeat incorrect mortality estimates.”
The program estimates that one breast cancer death for every 400 women is prevented by being screened on a regular basis over a ten year period – arguing against this the authors say:
“(the figure) is wrong by a factor of five. We have been unable to find any evidence for this estimate in reports from the Program or elsewhere. The 1993 meta-analysis of the Swedish trials reported that one breast cancer death was avoided for every 1000 invited women after ten years. The number is 2000 if we use the more realistic estimates of a 15% reduction in breast cancer mortality.”
They also stress that contradictory information about over-diagnosis is being provided by the NHS BSP.
“The (2010) Review has reverted to repeating the much too low estimate regarding over-diagnosis from the 2006 Review, but it is obscure as to where this figure comes from. The new leaflet never uses the term over-diagnosis, and although it talks a lot about ‘benefits’ it does not use the equivalent term ‘harms’ but just speaks about ‘downsides’, which is far less negative.”
In the report they explain that “the only hint at over-diagnosis” in the invitation leaflet is the sentence ‘Screening can find cancers which are treated but which may not otherwise have been found during your lifetime’. They believed this is vague and readers may understand that screening can only be good, as it detects cancers which would otherwise be hard to find.
The researchers tried out the sentence on a group of fourth year medical students – by this time in their training they still would now have had lectures about screening. They discovered almost half did not understand the sentence and one third believed it was bad for women to have these cancers detected.
The researchers said:
“There is no quantification of over-diagnosis in the leaflet and no estimate of the balance between benefit and harm.”
The Programs 2010 Annual Review was criticized by the authors for using sentences, such as..:
“If a breast cancer is found early, you are less likely
to have a mastectomy.”
..claiming that the program encouraged belief that screening will reduce the chances of the women needing to have a mastectomy. The authors express:
“But such claims are seriously misleading. Danish data has demonstrated that because of over-diagnosis, screening increases the use of mastectomies substantially.”
Written by Grace Rattue