Re: Screening has not reduced deaths from breast cancer, study shows
All that Brewster et al(1)say may be true. But do not they think at this juncture in the history of breast screening that it would have been decent for screeners to tell me, when they invited me to be screened, that screening is conducted on faith not evidence of benefit? Rather than misleading me to believe that I was more likely to die of breast cancer without screening, which claim they must agree is not and never has been warranted by the evidence.
That comparison of mortality trends is not an ideal way to show an effect of an intervention does not mean that it is okay to proceed with the intervention whistling in the dark in the absence of evidence of benefit. For 25 years. In the face of overwhelming harm, evidence of which is apparent to the naked eye.
Do they not think it would have been decent for my doctors to ensure that when receiving a diagnosis through screening I understood that this cannot mean that I “had cancer”, since a disputed but large proportion of screening diagnoses are clinically inconsequential, while the majority will not benefit from earlier detection and it is simply not known if any do. That at best they can be few, 1 in 15 according to their estimate, which Professor Marmot himself has admitted is uncertain. So that it would be better to use this figure by way of illustration to educate women about what screening means than as an accurate representation of any diagnosed woman’s actual probability of benefitting from the treatment she will at that point be too frightened to decline. And too preoccupied with current danger to be able to ask the obvious question, “Why didn’t you tell me this before you screened me?”
Why are they still defending screening in the face of insufficient evidence when, given what they know, they should be bending their efforts towards making sure every woman invited for screening understands the big risk of grave harm and the lack of evidence of chance of benefit?
More than half a year has passed since the review panel added its evaluation of screening to the existing range. While it is misleading to cherry pick this estimate to inform women rather than explaining the impossibility, given the nature of the evidence, of getting accurate figures, and therefore of being able to assure them that they have a chance of benefit, what is incomprehensible is the absence of any sign of urgency in informing women at all.
Another million women have been screened since then. 8000 encouraged to believe misleadingly they ‘have cancer’; about 5,350 will receive no benefit from earlier treatment; an optimistic 650 may die of something other than breast cancer though whether any live longer is unclear; 2000 didn’t ‘have cancer’. Nobody knows which is which. Yet they believe falsely ‘screening saved my life’, and these writers are letting this debacle continue while quibbling about studies.
(1)AGE-RELATED DIFFERENCES IN USE OF TREATMENT MEAN THAT IT IS NOT APPROPRIATE TO JUDGE THE EFFECTIVENESS OF MAMMOGRAPHIC SCREENING BY COMPARING BREAST CANCER MORTALITY TRENDS IN SCREENING AND NON-SCREENING AGE GROUPS David H Brewster, Director, Scottish Cancer Registry Lesley A Bhatti, Catherine S Thomson, David A Cameron, John A Dewar
BMJ 2013; 346:f3780
Rapid Response:
Re: Screening has not reduced deaths from breast cancer, study shows
All that Brewster et al(1)say may be true. But do not they think at this juncture in the history of breast screening that it would have been decent for screeners to tell me, when they invited me to be screened, that screening is conducted on faith not evidence of benefit? Rather than misleading me to believe that I was more likely to die of breast cancer without screening, which claim they must agree is not and never has been warranted by the evidence.
That comparison of mortality trends is not an ideal way to show an effect of an intervention does not mean that it is okay to proceed with the intervention whistling in the dark in the absence of evidence of benefit. For 25 years. In the face of overwhelming harm, evidence of which is apparent to the naked eye.
Do they not think it would have been decent for my doctors to ensure that when receiving a diagnosis through screening I understood that this cannot mean that I “had cancer”, since a disputed but large proportion of screening diagnoses are clinically inconsequential, while the majority will not benefit from earlier detection and it is simply not known if any do. That at best they can be few, 1 in 15 according to their estimate, which Professor Marmot himself has admitted is uncertain. So that it would be better to use this figure by way of illustration to educate women about what screening means than as an accurate representation of any diagnosed woman’s actual probability of benefitting from the treatment she will at that point be too frightened to decline. And too preoccupied with current danger to be able to ask the obvious question, “Why didn’t you tell me this before you screened me?”
Why are they still defending screening in the face of insufficient evidence when, given what they know, they should be bending their efforts towards making sure every woman invited for screening understands the big risk of grave harm and the lack of evidence of chance of benefit?
More than half a year has passed since the review panel added its evaluation of screening to the existing range. While it is misleading to cherry pick this estimate to inform women rather than explaining the impossibility, given the nature of the evidence, of getting accurate figures, and therefore of being able to assure them that they have a chance of benefit, what is incomprehensible is the absence of any sign of urgency in informing women at all.
Another million women have been screened since then. 8000 encouraged to believe misleadingly they ‘have cancer’; about 5,350 will receive no benefit from earlier treatment; an optimistic 650 may die of something other than breast cancer though whether any live longer is unclear; 2000 didn’t ‘have cancer’. Nobody knows which is which. Yet they believe falsely ‘screening saved my life’, and these writers are letting this debacle continue while quibbling about studies.
(1)AGE-RELATED DIFFERENCES IN USE OF TREATMENT MEAN THAT IT IS NOT APPROPRIATE TO JUDGE THE EFFECTIVENESS OF MAMMOGRAPHIC SCREENING BY COMPARING BREAST CANCER MORTALITY TRENDS IN SCREENING AND NON-SCREENING AGE GROUPS David H Brewster, Director, Scottish Cancer Registry Lesley A Bhatti, Catherine S Thomson, David A Cameron, John A Dewar
BMJ 2013; 346:f3780
miriam.pryke@kcl.ac.uk
Competing interests: Diagnosed through screening