Harm from mammography outweighs the benefits

Breast cancer screening cannot be justified, says researcher

Book argues harm outweighs small number of lives saved, and accuses mammography supporters of misconduct

Women in the UK are called for breast screening every three years from the age of 50. Photograph: Rui Vieira/PA

Breast cancer screening can no longer be justified, because the harm to many women from needless diagnosis and damaging treatment outweighs the small number of lives saved, according to a book that accuses many in the scientific establishment of misconduct in their efforts to bury the evidence of critics and keep mammography alive.
Peter Gøtzsche, director of the independent Nordic Cochrane Collaboration, has spent more than 10 years investigating and analysing data from the trials of breast screening that were run, mostly in Sweden, before countries such as the UK introduced their national programmes.
Mammography screening: truth, lies and controversy, from Radcliffe Publishing, spells out the findings of the Nordic Cochrane group for laywomen, rather than for scientists.
The data, Gøtzsche has maintained for more than a decade, does not support mass screening as a preventive measure. Screening does not cut breast cancer deaths by 30%, it saves probably one life for every 2,000 women who go for a mammogram. But it harms 10 others.

http://www.guardian.co.uk/science/2012/jan/23/breast-cancer-screening-not-justified

Bias in eye of beholder

There’s no doubt that doctors’ financial relationships with industry could be used — fairly or otherwise — to question their credibility.

In fact, this happened last week when Melbourne endocrinologist Professor Henry Burger and overseas colleagues published a re-evaluation of the results of the of the Million Women Study, disputing claims it showed a causal link between hormone replacement therapy (HRT) and increased breast cancer risk.

Predictably enough, the paper sparked a fiery debate. Some experts welcomed the finding; others disputed it and pointed to the authors’ financial relationships with manufacturers.

Dr Andrew Penman, of the NSW Cancer Council, told ABC radio the authors were “playing the game” of seeding doubt about well established scientific findings, “and you really do have to question their interest, given their association with the industry”.

No doubt, the HRT debate still has some distance to run, but the demand for greater public disclosure means doctors in all fields of medicine are likely to find themselves grappling with more of these kinds of conflict of interest allegations.

We humans are not very good at detecting our own biases, though we can be hyper-vigilant about those of others.

Studies in the past have suggested most doctors do not believe their own decisions are affected by industry gifts or payments — though they tend to be more sceptical about their colleagues’ ability to remain impartial.


http://www.mjainsight.com.au/view?post=jane-mccredie-bias-in-eye-of-beholder&post_id=7768&cat=comment

Confidence in research shattered

A REANALYSIS of evidence supporting the anti-influenza drug oseltamivir has undermined confidence in published research for one of the review authors, who has called for an overhaul of the way systematic reviews are conducted.

Professor Chris Del Mar, professor of public health at Bond University, Queensland, was one of seven Cochrane researchers who reanalysed the evidence for oseltamivir (Tamiflu) using primary trial data, much of which was unpublished. (1)

They found several inconsistencies with published reports, such as that oseltamivir did not reduce hospitalisations. The reanalysis also showed a possible underreporting of adverse events, although the drug was found to reduce duration of influenza symptoms by 21 hours.

Governments globally had spent billions of dollars stockpiling oseltamivir after a previously published analysis, funded by Roche, found that the drug reduced complications and hospital admissions. However, eight out of the 10 trials used in the Roche analysis were unpublished and their data sets were not available from either the authors or Roche. (2)

The researchers postponed an analysis of zanamivir (Relenza) evidence because its manufacturer, GlaxoSmithKline offered to provide individual patient data.

The Cochrane researchers found that 60% of patient data from oseltamivir trials had never been published, a fact Professor Del Mar described as “disgraceful”.

http://www.mjainsight.com.au/view?post=confidence-in-research-shattered&post_id=7790&cat=news-and-research