I have not read the whole paper (although I did look at the summary in the Lancet) and am not really qualified to comment but...........
The concern is not one of misdiagnosis, the women screened are correctly identified as having breast cancer, it is the use of more treatment (or, indeed, any treatment) than is necessary for that particular patient. It appears that a percentage of women with breast cancer would lead healthy lives without the cancer developing in any significant way. Unfortunately, once the cancer has been diagnosed, a doctor cannot tell how or if the tumour will progress and thus naturally errs on the side of caution and advises surgery or whatever.
I am fully in favour of every person being given as much information as possible about their disease to enable them to make a rational and balanced decision about treatment or not to be treated. I also feel that adequate time should be given to enable people to understand a diagnosis before having a treatment plan foisted upon them. However, I do not think it is sensible to discourage women from having mammograms which have significantly reduced the death toll from breast cancer.
Glad I am in France!
And roll on summer at last, my bit of the "sunny mediterranean" has been very bleak during Spring, today we have had suitable June weather and supper on the terrace!