The 50-60% figure is based on ten annual mammograms.
In a given mammogram it's more like 7-12%.
The younger you are, the more likely your positive result will be a false positive. And it also varies based on tissue density (women with more dense breasts have higher false positive rates). The higher false positive rate in younger women is of course why they've shifted screening times, pushing back the suggested start age and or doing every other year instead of every year.
If you recall someone from screening for additional diagnostic views, this is not strictly a false positive as the initial evaluation is definitionally incomplete. However, many would argue the additional views result in additional patient stress and anxiety (I personally do not buy this argument especially if you set expectations at the time of initial image acquisition).
Of the patients who are recalled, maybe 20% proceed to biopsy, of which probably 20% have histologic cancer and another percentage have high risk lesions that are not cancerous per se but are often surgically removed as they either cannot be fully sampled using a minimally invasive technique.
Recall rates are tracked and heavily scrutinized at the individual radiologist level. The targeted recall rate is in the range of 5-10% with the assumption that recalling more than this is being too sensitive and less than this is potentially missing cancer.
Mammography performance is often defined in cancers per 1000 screening exams for a given population.
Realistically, someone needs to proceed to all the way to biopsy (and have it come back negative) to have a real false positive.
Someone being recalled from screening for additional views only to be released as “superimposed tissue” or “benign finding” is not a true false positive. To argue so is being a bit disingenuous.
In a given mammogram it's more like 7-12%.
The younger you are, the more likely your positive result will be a false positive. And it also varies based on tissue density (women with more dense breasts have higher false positive rates). The higher false positive rate in younger women is of course why they've shifted screening times, pushing back the suggested start age and or doing every other year instead of every year.