What's typical PSA drop over time after SBRT?

[LiveLongAndPropser]

Hi All,

I'm 10 months post SBRT w/o ADT (on a study that randomized me for no ADT with low Decipher score), so wondering if anyone has any info on what I would expect for PSA percentage drop over time? A year ago my PSA was 11.0 and this past week, I'm at 5.3. I'm happy that it is less than half what it was, but wondering when, or if, I should expect it drop to below 1?

Thanks,

Trevor

[SadandScared]

Hello! Glad to hear that things are going well I am 6 months out from my Cyberknife. I started with a PSA of 13.72, then 3 months later, it came down to 6.97 and now 6 months after, it's at 7.69.

My oncologist is ok with it and told me that it can go up and down for the 1st year but my urologist was very alarmed and stated that it should be much lower at this point.

I would love to get everyone's take on this as well.

[GeoffoB]

Mine was 9.4 prior to SBRT no ADT and was 0.9 6 months later. I remember the Rad Oncologist saying he expected it to be under 1. My next PSA test (12 months) is in September

[cbreston]

LiveLong, Can you give any information on that randomized trial? In particular, any prior studies they mentioned as justifying the hypothesis on which your trial is based.

I'm especially interested, because The Decipher results claim, "Patients considering definitive treatment may have excellent oncologic outcomes when treated with local therapy alone. [2-5]" Reading the references, on #3 [Spratt, DE et al. J Clin Oneal 36, 581-590 (2018)] actually seems to directly support that claim, proposing a system to reclassify severity categories based on Decipher results. The others just pertain to AS or show that Decipher adds about 0.1 to prediction accuracy, on top of the usual criteria.

Presumably this trial is for a variation on the AUA guidance, "...a choice between radical prostatectomy or radiation therapy plus androgen deprivation therapy (ADT). (Strong Recommendation; Evidence Level: Grade A)"

[LiveLongAndPropser in reply to cbreston]

Hi cbreston,

The research study is the GUIDANCE study for intermediate risk patients with low gene risk score. Here's a link to info from NIH:

cancer.gov/research/partici...

[cbreston in reply to LiveLongAndPropser]

Perfect, thank you!

If there is a place that collects trials underway or newly published, I'd love to see it.

(Still missing the email listserv from my father's time, which had an amazing store of knowledge. That's somehow now dispersed into dozens of support groups and low-activity sites that mostly do other things.)