Medical test accuracy
Discussion
Anyone qualified to comment on accuracy of hospital lab tests re: repeatability?
Specific item is CA19-9, pancreatic cancer marker. Person is question first is receiving periodic tests for this, and whilst still very low for it to be a concern of actual cancer, the results are fluctuating which, for an admitted hypochondriac, is a cause for major worry.
Last 3 tests have come back 44, 39, 44. I can’t help but think that these must be the same result just within the margins of error for the testing process. Is this correct? Anything I can point to to help put someone’s mind at ease?
Specific item is CA19-9, pancreatic cancer marker. Person is question first is receiving periodic tests for this, and whilst still very low for it to be a concern of actual cancer, the results are fluctuating which, for an admitted hypochondriac, is a cause for major worry.
Last 3 tests have come back 44, 39, 44. I can’t help but think that these must be the same result just within the margins of error for the testing process. Is this correct? Anything I can point to to help put someone’s mind at ease?
Could you ask that the doctor/nurse takes two samples next time, to give some measure of reassurance that when the same blood comes back with marginally different results, its perfectly normal. The other explanation that seems reasonable is that the levels of the thing they are looking at wobble as well, which seems plausible, given how complicated the body is.
Yes this is what I advised. Most recent test was Monday and she’s had another sample taken privately today. Her concern is that it was climbing then went down after being prescribed supplements but has now gone back up. I’ve advised (guessed) that diet and other biological functions could cause a small fluctuation and also the test accuracy. I’d have thought 2 samples taken and processed the same day could return this level of spread. But tbh this is from my experience in oil/fuel sampling which, whilst done to ISO standards, isn’t really the same thing.
Most of us would be ok with these explanations but she is a hypochondriac (genuinely, admits it) and so I need some medical paper or test accuracy info I can pass on. It’s set her right on edge and ime this doesn’t subside quickly.
Most of us would be ok with these explanations but she is a hypochondriac (genuinely, admits it) and so I need some medical paper or test accuracy info I can pass on. It’s set her right on edge and ime this doesn’t subside quickly.
While the precis seems to suggest a significantly broader spread in the general population, this probably wont be enough to clam a hypochondriac:
https://pubmed.ncbi.nlm.nih.gov/17926198/
https://pubmed.ncbi.nlm.nih.gov/17926198/
Blood assays like these tend to be pretty accurate. As those figures are just slightly above normal range, there probably isn't anything to be worried about.
If they had active cancer the levels might be several orders of magnitude higher.
This isn't a sure fire assay either for pancreatic cancer and the serum levels of CA19-9 can be elevated for other reasons, from other pathological processes.
Why are they getting tested for this in the first place?
Link to the test - https://labtestsonline.org.uk/tests/cancer-antigen...
If they had active cancer the levels might be several orders of magnitude higher.
This isn't a sure fire assay either for pancreatic cancer and the serum levels of CA19-9 can be elevated for other reasons, from other pathological processes.
Why are they getting tested for this in the first place?
Link to the test - https://labtestsonline.org.uk/tests/cancer-antigen...
Yahonza said:
Why are they getting tested for this in the first place?
Part of a whittling down of (genuine) issues presented, some of which fit a diagnosis. Lots of blood work and other tests. I say genuine as she is aware of her hypochondria (it’s weird as both parents were doctors) so doesn’t invent issues. Only when she has some, needs to go down every test Avenue to either discover the cause or else set her mind at ease that it’s natural aging (41yo). We are midway through this process.
Well knowing too much can some times be part of the problem. Especially if there is a touch of hypochondria. Better to be aware though than to live in blissful ignorance.
Pancreatic cancer is no joke with one of the poorest 5 year survival rates and symptoms often arrive with no warning at all.
Some of the current treatments extend survival though and early diagnosis is key - so maybe they aren't that daft in worrying about it!
Pancreatic cancer is no joke with one of the poorest 5 year survival rates and symptoms often arrive with no warning at all.
Some of the current treatments extend survival though and early diagnosis is key - so maybe they aren't that daft in worrying about it!
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