Statistics, mammograms and cancer statistics

Interesting stats but a bit puzzling in parts. I don't think you 'test postive' for cancer from a mammogram. The mammogram will highlight abnormalities that require further investigation, often a biopsy...and this will potentially lead to a positive diagnosis. I was called back for further testing after a mammagram in January and the accompanying literature said that two-thirds of those called back required no further intervention, ie, didn't have cancer.

I agree Notso that mammograms only highlight abnormalities.

What I found worrying about the article was that out of 1000 women tested, there will be one false negative, and 89 false positives. That seems quite a high rate.

As far as dental Xrays go, I think most dentists in practice wouldn't routinely Xray children's teeth to detect decay (as opposed to checking whether all teeth were present, or there were any extra teeth, for example), but it is actually recommended by Dr Edwina Kidd, an eminent academic dentist, as a means of deciding whether decayed teeth should be filled or not.

I don't think it is realistic to expect general practitioners to be able to reel off exact risk levels for brain cancer or thyroid cancer from dental x-rays - with modern film and techniques it is infinitesimally small, anyway. I used to tell patients they got a higher dose of radiation flying to Spain than from routine dental x-rays.

I was called back once and after a second x-ray diagnosed with a cist, which some years later did become infected and treated with antibiotics.

As Notso says, mammograms identify anomalies not cancer.