5 ms·

Yes exactly. In fact mammograms are already double-read and agreement is quite high, so this is definitely one of those types of tests. There are benign masses

Yes exactly. In fact mammograms are already double-read and agreement is quite high, so this is definitely one of those types of tests. There are benign masses that are radiologically impossible to distinguish until you get a biopsy.

lostlogin 4y ago
> There are benign masses that are radiologically impossible to distinguish Time to bring out the pigeons. Having just read the paper again, It’s fascinating. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4651348/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4651348/
jvanderbot 4y ago
Seems to me the thesis that "mammogram positive" implies "possible cancer" is the faulty one. In fact, "mammogram indeterminate" is a better diagnosis.
- dontreact 4y ago
  Yes, and this is how the standard of care treats things. You never proceed from positive mammo screen to treatment. You always first do some other steps like ultrasound or biopsy.
  - belorn 4y ago
    In the general case, this is the point where medicine arrive at both a medical and ethical problem. The biopsy and further tests both involve some non-insignificant risk to the patient, as does overtreatment. If 99% or even higher number of patients are false positive, and the biopsy has a risk of causing significant negative sides, at what point is testing doing more harm that good? This is the general argument against testing for prostate cancer in non-symptomatic patients. If you only test patients that has symptoms then the rate of false positives goes down. The downside is that you only catch late stage patients where treatment might be too late. The alternative (which is used for mammography) is that for every person saved, an order of magnitude more will be permanent harmed by unnecessary surgery.
    - dontreact 4y ago
      Yes it's not trivial to balance these things and this is why there have been randomized control trials that look at long term end points where both the costs of false negatives and false positives come into play. It's also why breast cancer screening is not recommended for everyone, just women over 50. For women over 50 there has been a decades long sincere effort by the medical community to take this all into account and the consensus is that screening makes sense in that population.
  - sgent 4y ago
    Yes, but every positive mammogram means a percentage of people are going to get treatment, including surgery and radiation/chemotherapy, who never would have developed cancer -- and screening more women, especially those who are likely to generate false positives (younger women) is a very big problem in preventative medicine, especially when introducing a new modality like "3d" mammograms. Orac / David Gorski, MD (Surgical Oncologist (Breast)) has blogged extensive. A good if old starting place is https://sciencebasedmedicine.org/a-holiday-round-in-the-mammography-debate/ https://sciencebasedmedicine.org/a-holiday-round-in-the-mamm...
- dragonwriter 4y ago
  > Seems to me the thesis that "mammogram positive" implies "possible cancer" is the faulty one. It's not, though. Possible ≠ certain or even likely. Screening tests are used to determine whether there are indications for more invasive but more conclusive diagnostic tests.
  - Dylan16807 4y ago
    > Possible ≠ certain or even likely. Yeah but "possible cancer", taken literally like that, is everyone.

lostlogin 4y ago

> There are benign masses that are radiologically impossible to distinguish Time to bring out the pigeons. Having just read the paper again, It’s fascinating. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4651348/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4651348/

jvanderbot 4y ago

Seems to me the thesis that "mammogram positive" implies "possible cancer" is the faulty one. In fact, "mammogram indeterminate" is a better diagnosis.

dontreact 4y ago
Yes, and this is how the standard of care treats things. You never proceed from positive mammo screen to treatment. You always first do some other steps like ultrasound or biopsy.
- belorn 4y ago
  In the general case, this is the point where medicine arrive at both a medical and ethical problem. The biopsy and further tests both involve some non-insignificant risk to the patient, as does overtreatment. If 99% or even higher number of patients are false positive, and the biopsy has a risk of causing significant negative sides, at what point is testing doing more harm that good? This is the general argument against testing for prostate cancer in non-symptomatic patients. If you only test patients that has symptoms then the rate of false positives goes down. The downside is that you only catch late stage patients where treatment might be too late. The alternative (which is used for mammography) is that for every person saved, an order of magnitude more will be permanent harmed by unnecessary surgery.
  - dontreact 4y ago
    Yes it's not trivial to balance these things and this is why there have been randomized control trials that look at long term end points where both the costs of false negatives and false positives come into play. It's also why breast cancer screening is not recommended for everyone, just women over 50. For women over 50 there has been a decades long sincere effort by the medical community to take this all into account and the consensus is that screening makes sense in that population.
- sgent 4y ago
  Yes, but every positive mammogram means a percentage of people are going to get treatment, including surgery and radiation/chemotherapy, who never would have developed cancer -- and screening more women, especially those who are likely to generate false positives (younger women) is a very big problem in preventative medicine, especially when introducing a new modality like "3d" mammograms. Orac / David Gorski, MD (Surgical Oncologist (Breast)) has blogged extensive. A good if old starting place is https://sciencebasedmedicine.org/a-holiday-round-in-the-mammography-debate/ https://sciencebasedmedicine.org/a-holiday-round-in-the-mamm...
dragonwriter 4y ago
> Seems to me the thesis that "mammogram positive" implies "possible cancer" is the faulty one. It's not, though. Possible ≠ certain or even likely. Screening tests are used to determine whether there are indications for more invasive but more conclusive diagnostic tests.
- Dylan16807 4y ago
  > Possible ≠ certain or even likely. Yeah but "possible cancer", taken literally like that, is everyone.