Cordova, Alaska, Coast Guard detachment
My daughter
Kristen once echoed my sense of frustration, writing “Why isn’t there a simple
blood test that will tell you whether you have cancer?” At that time I was volunteering for a
big-time research project aimed at developing exactly such a test. We worked on it for several years, spent $8
million of your tax dollars – and failed.
Turns out the problem is not as simple as it ought to be.
The link
below will bring you up to date with progress along this line. The specific question addressed is: if you
have a lump of stuff in your uterus, should you be referred to a specialist for
possible surgery? To answer that
question several blood-sample tests have been developed. Clearly, if CA 125 is elevated they send you
off to a specialist clinic. The other
tests described in this article depend on multiple proteins in the blood plus
menopausal status; as such they actually are computer algorithms. One you are familiar with (if you read my
blog) is ROMA: the Risk of Malignancy Algorithm. Several more are described, possibly better than ROMA in some ways.
The bottom
line is that your local doc should know about these things and make efficient
use of them. The article below makes it
clear that applying these tests to the common asymptomatic woman who wanders in
off the street is “inefficient” and is not recommended. My take is: if it’s cheap and easy, go for
it.
If you read this link (big “if”, I’m
afraid) you might need to be reminded of some medical stat things:
Sensitivity: the probability that, if the test
says you’ve got it you really do
Specificity: The probability that, if the test says
you don’t have it, you really don’t.
PPV (Positive Predictive Value): The number of true positives, divided by the
sum of true positives and true negatives.
Bottom line: the bigger these things are,
the better
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