Decipher is a "genomic classifier" done on prostatectomy tissue. It tells one the probability that the person will experience metastases in the next 5 years. I think it's expensive (about
$4,000), and there are some problems with it, but it is, overall, a pretty good test (with a few caveats).
The caveats are:
• It has never been validated prospectively. That means, they never took a bunch of post-prostatectomy guys and randomized them to get Decipher or not get Decipher, and then see how they did with or without the test. This is how a patient getting the test would experience it. They only evaluated tissue samples retrospectively - after they already had data on how it turned out. Would it make a difference? Hard to say.
• They tell you the probability that your type of PC will progress to metastasis in the next 5 years if you didn't have salvage radiation or adjuvant hormone therapy. Several years ago, a Johns Hopkins study showed that the average time from surgery to discoverable metastases was about
10 years. And it may be longer than that now that PC is discovered earlier. 5 years is not enough.
• At a cutpoint of 0.4, it has a negative predictive value (NPV) of 98% which is excellent. But it has a positive predictive value (PPV) of 69%. That means that if you get a Decipher score under 0.4, it is great at telling you that you have a low risk of mets in the next 5 years (like the OP). However, if your Decipher score is greater than 0.4, it is only accurate at predicting metastatic progression about
two-thirds of the time. In about
a third of the cases, it will be a false positive, predicting 5-year metastatic progression when, in fact, there will be none. Those men might get treatment they didn't need.
Here's my article about
it:Genomic classifier can help identify patients who may not need adjuvant radiation.
Allen - not an MD
•PSA=7.3, prostate volume=55cc, 8/17 cores G6 5-35% involvement
•SBRT 9 yr onc. results
•SBRT 7 yr QOL results
•treated 10/2010 at age 57 at UCLA,PSA now: 0.2,no lasting urinary, rectal or sexual SEsmy PC blog