'governments,researchers,Drs may have vested interests in continuing activities (breast screening)

[Esther12]

Just saw Wessely's wife tweet about this BMJ article that found no benefits for breast screening.

Clare Gerada ‏@clarercgp
@bmj_latest 'governments,researchers,Drs may have vested interests in continuing activities that not well established' (breast screen)

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2:30 PM - 15 Feb 2014 from Lambeth, London

https://twitter.com/clarercgp/status/434681217934716928

(I thought that sort of thing was hurtful and harassing, conspiratorial accusations?.. Although also, obviously true.)

The BMJ article is currently open access, but they often go behind the paywall after a while.


http://www.bmj.com/content/348/bmj.g366

From a rapid response:

In my own personal, rather exhaustive, investigation of the value of mammography I have encountered numerous instances of omission, denial, derision, and obfuscation of genuinely relevant scientific data by the supporters of screening with mammography, shifting the "evidence" artificially in favor of the procedure. As a result, the general public and particularly women who decide to subject themselves to mammography, unfortunately, have been hampered from making an "informed choice" about this controversial test.

http://www.bmj.com/content/348/bmj.g366/rr/686736

Also, this rapid response:

The recent publication by Miller et al. [1] indicating no mortality benefits from mammography as part of the Canadian National Breast Screening Study is fraught with bias and the conclusions deeply suspect.

The study ignores pre-invasive cancers which have a high survival rate and are often detectable by mammography. It is reasonable to assume that if they had been included in the analysis then the mammography arm of the trial would have demonstrated higher survival rates than those reported. It is not safe to assume that all pre-invasive cancers are indolent (ie. that they would never go on to harm the patient), especially since the standard model of malignant tumour growth has invasive cancers first developing through a pre-invasive stage.

The study’s results contradict the authors’ conclusion that mammography is not assisting in saving women’s lives. The section of the Results titled “Breast cancer survival” indicates that “The 25 year survival was 70.6% for women with breast cancer detected in the mammography arm and 62.8% for women with cancers diagnosed in the control arm” which the authors demonstrate to be a statistically significant difference. This demonstrates a real benefit to women surviving breast cancer thanks to receiving mammographic screening. Had pre-invasive cancers been included in this study the difference in 25 year survival is liable to have been even larger. Concluding that mammographic screening provides no benefit with respect to saving women’s lives based on the analysis presented [1] is unfounded and dangerous.

[1] A. B. Miller, C. Wall, C. J. Baines, P. Sun, T. To, S. A. Narod, “Twenty five year follow-up for breast cancer incidence and mortality of the Canadian National Breast Screening Study: randomised screening trial,” British Medical Journal, 2014;348:g366.

http://www.bmj.com/content/348/bmj.g366/rr/686749

No idea where I stand on it, but always good to see an honest discussion, without the pretence that everyone's intentions are good.