Wow, you have been very informative and have given me food for thought and questions to discuss with his Dr. The one question I can answer now is that all test have been done in the same lab.
The "less than" sign that you used is actually the "greater than" sign, did you mean to say "greater than" 0.01?
When I have answers I will let you guys know. Thanks for all your help.
You are welcome; glad to help. And you are absolutely correct that I mistakenly flipped the sign. [This is the same reason that on a check you have to both write out the numbers and the words; whenever they are in conflict, the words overrule. The thought being that the quick writing of the numbers (or in this case the sign) might be more prone to error than the writing out of the words.] Thank you for pointing out my mistake; often these posts are re-read by others later, and I wouldn't want that to be uncorrected.
When the PSA result is less than the test's lower detection limit, it is undetectible....just let those words sink in for a minute, they are sort-of redundant. (This is also answering Stephie's question.) When it is below the detection limit of the test, it gets written out as less than the lower detection limit (LDL).
So, if you had the "standard" PSA test which has a lower detection limit (LDL) of 0.1 ng/mL (just one figure to the right of the decimal point), and your test result was less than 0.1 ng/mL, it would be reported as "undetectable" or <0.1ng/mL (I got the sign correct that time).
On the other hand, your husband appears to have had what's known as the "ultrasensitive" PSA test which typically has a LDL of 0.01ng/mL. [I say "typically" because there are more than one ultrasensitive PSA tests, with slightly different LDLs; the most common ultrasensitive PSA test has a LDL of 0.01 ng/mL, and the second most common has a LDL of 0.008ng/mL.] Since his results were reported with two figures to the right of the decimal point, your husband's test was one of the ultrasensitive PSA tests.
Some doctors prescribe the standard test after RP, others prescribe the ultrasensitive test after RP. In general, if the pathology report shows no positive surgical margins (PSM) or extraprostaic extension (EPE), and the final Gleason was 3+4 or less (maybe some other factors, too), then most doctors prescribe the standard PSA test because it is a low probability that the patient will have biochemical recurrence (BCR). If, on the other hand, the patient had PSMs, EPE or 4+3 or greater, there starts to be a decent chance of BCR, and in these cases are best-suited for the ultrasensitive test in order to monitor more closely the early possible progression. These, however, are just general rules; some doctors only prescribe, for example, the ultrasensitive test no matter what, and the opposite might also be true...but I've detailed out the most commonly accepted rules of thumb.
So, without putting words into Stephie's mouth, I think was she was saying was that even if someone has a detectible level of 0.05 ng/mL from an ultrasensitive test (as your husband did), that low level would have been undetectible if the standard test had been performed instead. It is detectible from the test that was performed, but would likely have been undetectible on the standard test.
I hope that after all those words I have reduced, rather than increased, any confusion there might have been...
edit: fixed typos
Post Edited (Casey59) : 9/21/2010 2:48:44 PM (GMT-6)