Comment by IshKebab
9 days ago
I 100% agree. The UK recently recommended to not scan for prostate cancer because it sometimes detects cancers that don't need treatment:
https://www.bbc.com/news/articles/cm20169gz44o.amp
This seems super dumb to me. If the test detects cancer that doesn't need treatment, don't treat it!! It's still better to know it's there and that you need to monitor it.
> Before you know it, you are on the operating table having your prostate removed – and we see examples of that all the time,
Well fix that problem then. If someone puts a smoke detector above a toaster you don't just pull the battery and call it a day.
My parents are doctors so I’m very used to giving them all the data and pushing decision making down to them. Almost all of the time there is no action to be taken. But this built a certain habit that I realized is not conducive to medical care in the US.
I once told my wife that it’s better if she just passes all information downstream and then lets the diagnostician do the diagnostics.
During her pregnancy, at antenatal monitoring, when asked the routine questions I encouraged her to mention everything and so she mentioned a slight twinge in her chest (“it’s probably nothing, maybe something I ate”). She was hooked up to the monitors and so on but this was a sudden moment of panic for everyone but us. The nurse called for a doctor, there was an EKG machine brought up, all sorts of honestly nonsensical reaction given the data.
I realized my mistake soon after. There’s the obvious legal consideration, of course, but the real magic lies in the fact that no one gives full information so if someone sends you a signal they assume it’s crossed some threshold to significance. My mistake was in being a non-normative participant here, akin to someone who drives straight on green in a land where a green light means you first let one person turn left before you go.
Anyway, patients are supposed to perform pre-diagnosis in the US. And you’re not supposed to show your doctor things that they will then act on. You should first apply Bayes yourself and then give the info to the doctor here because they won’t use Bayes.
> Well fix that problem then. If someone puts a smoke detector above a toaster you don't just pull the battery and call it a day.
I think what's happening here is that the smoke detector is indicating the possibility of fire, but the toaster is always being immediately doused in water. Which as we know would cause more damage than good unless there truly was a raging inferno.
The suggestion here seems to be moving the smoke detector to somewhere where there's a higher chance of it ringing means a higher chance of a damaging fire. Which seems quite reasonable.
The question is how can you know if it needs treatment or not. I guess you either need to do a biopsy, or check if it's grown after N months (leaving patient scared and anxious during that time). Neither are great if most cases end up not needing treatment.
If the test provides you zero information about whether it needs treating then it was never a useful test. Presumably it's more like "there's a X% chance this needs treatment". In which case you just set reasonable thresholds for X. E.g. if it's 5% you monitor it, 10% you do a biopsy, 70% you operate, etc.
This is much more sensible than just not testing at all and letting people die from cancer.
> leaving patient scared and anxious during that time
This seems to be the actual motivation. We don't want to scare people with test results so we're just not going to test them. I think that should be up to the patient.
> This is much more sensible than just not testing at all and letting people die from cancer.
This is not what happens. You're assuming that if the cancer does not get detected by the screening then it never gets detected. What actually happens is that the test gives information that might actually be redundant and obtainable in less risky way. What the studies are showing is that waiting until there are other, more specific signs and symptoms of the prostate cancer results in the same survival rates.
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> If the test detects cancer that doesn't need treatment, don't treat it!!
How do you know which ones to treat and which ones to leave?
When the result is above a chosen threshold (which may depend on other factors like family history etc.).
Unfortunately that "chosen threshold" is really hard to know, specially if you want to balance individual and population level necessities.