I guess the problem is a mismatch between detection capability and treatment capability? We seem to be getting increasingly good at detecting precancerous states but we don't have corresponding precancer treatments, just the regular cancer treatments like chemo or surgery which are a big hit to quality of life, expensive, harmful etc.
Like if we had some kind of prophylactic cancer treatment that was easy/cheap/safe enough to recommend to people even on mild suspicion of cancer with false positives, we could offer it to positive tests. Maybe even just lifestyle interventions if those are proven to work. That's probably very difficult though, just dreaming out loud.
>I guess the problem is a mismatch between detection capability and treatment capability?
the problem is you do the test for 7 billion people, say, 30 times over their life... 210000000000 tests. imagine how many false negatives and false positives, the cost of follow up testing only to find... false positive. the cost of telling someone they have cancer when they don't. the anger of telling someone they are free of cancer, only to find out they had it all along
this tech isn't that good, nowhere near it, more like a 1 in 100 or 10 in 100 rate of "being wrong". those numbers can get cheesed towards more false positives or false negatives.
as for grail, they tried to achieve this and printed OK numbers... ... .. but their test set was their training set. so the performance metrics went to shit when they rolled it out to production
I think chemo in general kills rapidly dividing cells, which is a characteristic of cancer cells and, unfortunately, many types of regular cells as well, hence many of the side effects, like hair loss. If it is precancerous, then probably it’s not yet dividing in that way, so probably wouldn’t make much of a difference, unless you’d actually catch the moment when the switch to full fledged malignant happens.
Chemo poisons the whole body in an attempt to destroy the cancer before the treatment kills the person. Not something you would want to do precancerous I suspect. Many of the targeted treatments we now have would also not be suitable, as they can't target (or find) a cancer so small as to be deemed precancerous. But I imagine some treatments would, such as drugs targeting the cancer DNA.
Like if we had some kind of prophylactic cancer treatment that was easy/cheap/safe enough to recommend to people even on mild suspicion of cancer with false positives, we could offer it to positive tests. Maybe even just lifestyle interventions if those are proven to work. That's probably very difficult though, just dreaming out loud.