mHSPCa with undetectable PSA - chemo-only?

[Purple-Bike]

Is chemo-only justified, without ADT/androgen receptor pathway inhibitors, in a case like mine with two new mets discovered and with PSA less than 0.1? I have had no SOC medication since 2.5 years, after SRBR to a single identified met. Gleason 9.

This study points to ADT not being of benefit to low-PSA high-Gleason, however in non-metastatic prostate cancer (in fact AHR adjusted hazard ratio was above 1).

Clinical and Genomic Characterization of Low–Prostate-specific Antigen, High-grade Prostate Cancer - ScienceDirect %).

"Among Gleason 8–10 patients treated with radiotherapy, androgen deprivation therapy was associated with a survival benefit for PSA >2.5 ng/ml (AHR 0.87; p 2.5 ng/ml (p = 0.046), with no such relationship for Gleason ≤7 disease.

Low-PSA, high-grade prostate cancer has very high risk for PCSM, potentially responds poorly to androgen deprivation therapy, and is associated with neuroendocrine genomic features".

The following study, that I found in TA:s newsletter, but again in non-metastatic PCa, points to chemo being very beneficial, but in addition to SOC/ADT,

Mortality Risk for Docetaxel-Treated, High-Grade Prostate Cancer With Low PSA Levels: A Meta-Analysis | Oncology | JAMA Network Open | JAMA Network

“adding docetaxel to SOC treatment in patients with prostate cancer who are in otherwise good health with a PSA level of less than 4 ng/mLand a Gleason score of 8 to 10was associated with a significant reduction in prostate cancer specific mortality” “By adding docetaxel to the SOC treatment, the absolute prostate cancer specific mortality rate decreased more than 3 -fold (from 14 to 5) in patients with a performance status of 0” ( i.e. in good health).

Contrary to the first study, this study indicates ADT should be used for the low-PSA “Therefore, we believe it is prudent to consider long-term ADT as part of the testosterone suppression treatment plan when using radiotherapy as the local treatment in patients with Gleason scores of 8 to 10 and PSA levels of less than 4 ng/mL”

Again, both of these studies are for non-metastatic disease. I have not been able to find any study on treatment for low-PSA metastatic disease.

[Mrtroxely]

What's are your taking from this info.

I've got Gleason 9

Diagnosed PSA 19

Biculamide and adt took PSA down quickly to 0.1 and below.

PSA rose consistently but always minutely during chemotherapy.....

(I'm still recovering from chemo, 'not cancer' and in hindsight wouldn't have done chemotherapy knowing what I do now!)

Radiotherapy gave little bump, but returned to 0.1

Last PSA was 0.25.

For me entering chemotherapy with low PSA result didn't seem good info from my oncologist?

[Purple-Bike in reply to Mrtroxely]

I don't dare give any comment would be on shaky ground....

[Purple-Bike]

Oops - belatedly I see a reply from TA to a similar question I posed 3 years ago, with him commenting the first study I linked to above:

"I think you are misinterpreting that observational, retrospective study. It was not a randomized clinical trial among men with low PSA subtypes where some men were given ADT and some were not. It only shows that the low PSA subtype has poorer outcomes and doesn't respond as well to normal ADT. It argues for the opposite of your conclusion - treatment intensification, rather than less ADT".

So the best treatment in a case like mine may be ADT + ARPI + chemo

[tango65]

My understanding is that chemo offers and advantage to patients with more than 4 or 5 metastases.