Scandinavian researchers report in the BMJ this week on their study suggesting a 10% over-diagnosis of breast cancers from a mammography screening program.
"Over diagnosis" means finding early cancers or "pseudo-cancers" that would not have caused harm in the woman's lifetime.
Others reacting to the study think it underestimated the rate of overdiagnosis -- that it may be more like 24 - 30%.
There's been an interesting progression to the discussion in the BMJ recently. As editor Fiona Godlee points out, "Three weeks ago an editorial in the BMJ concluded that despite limitations, breast cancer screening does save lives. But in the same issue of the journal we published an analysis ... of the letters inviting women for screening. None of the letters mentioned the major harms of screening, and the authors concluded that organisers of screening programmes have a serious conflict of interest in wanting high uptake, which compromises their ability to provide balanced information about benefits and harms."