Can prostate cancer spread while psa is going down?

[sem275]

Hi, my dad has been on xtandi since January. Went from PSA 50 to 20 after 4 weeks, still 20 a month later and now 10 in April. So seems to be responding but his scans showed possible new spots on his liver. The hospital are looking at them again and so we are waiting patiently and hoping it is nothing. They said they think it unlikely to be the cancer as have never seen this spread happen while psa is still going down. Sure I read about pca cells that don’t give out psa? I know we have to wait for the results but interested in similar experiences. A bit about his treatment so far - He was diagnosed 18 months ago with shoulder and back Mets, PSA 75. Had about 12 - 14 months on hormone injections before this stopped working. Chemo a few months after diagnosis which went well.In October last year his PSA was 1.6, by January 2019 it was 20 with spread to ribs and pelvis. A few weeks later PSA 50 and that is when he started xtandi.

[CalBear74]

Not an expert (non-physician) on this subject, but my urologist told me several years ago when I first started hormone therapy that a PSA in the teens or higher signals possible metastatic spread could occur. Your father has been transitioning through a status it seems when PSA indicates metastases may occur. I have never heard the comment before about a declining PSA, which is not to say as a generalization it may have some validity.

[sem275 in reply to CalBear74]

Thanks CalBear74 for your reply, that makes sense, fingers crossed it is nothing

[timotur]

Not a Dr, but lower PSA indicates a smaller tumor size, and thus less chances of it spreading. Mine was 33, at dx T3b M1 N0, no mets. After 3 weeks on Casodex, fell to 21. Checking PSA this week after starting Zytiga two weeks ago.

[sem275 in reply to timotur]

Thanks timotur, good luck with your tests and zytiga

[The_Don5]

I Recall MO saying spread can occur that is not PSA sensitive so being produced in cells that is not reflected in PSA levels... Don't quote me as the conversation was a while ago