@yfarah57
Did you get surgery or radiation as your initial treatment?

When Your PSA is rising, even though you are on ADT you have become castrate resistant. Median survival once you are castrate resistant is two years. I became castrate resistant six years ago, The ARPI drugs have enabled me to live longer than the median. I was on Zytiga for 2 1/2 years and have been on Nubeqa (Darolutamide) For three years. I’ve been undetectable for the last 25 months. If you started off with surgery, they can do salvage radiation Which can give you more time, They gave me an extra 2 1/2 years.

If you got surgery and your PSA hit .3 you need to do more than just wait for the next test. If you started off with radiation then, they will wait longer before doing more procedures. A PSMA pet test can show whether or not the cancer has spread visibly in your body.

ASCO, which sets standards for treatment has the following to say if you started off with surgery

From Ascopubs about what PSA to do salvage radiation.
≤0.2 ng/mL:
Starting at this level maximizes disease control and long-term survival. Patients treated at PSA < 0.2 ng/mL achieve higher rates of undetectable post-SRT PSA (56-70%) and improved 5-year progression-free survival (62.7-75%).
Delaying SRT beyond PSA ≥0.25 ng/mL increases mortality risk by ~50%.

0.2–0.5 ng/mL:
Still effective, particularly for patients with low-risk features (e.g., Gleason ≤7, slow PSA doubling time). The Journal of Clinical Oncology recommends SRT before PSA exceeds 0.25 ng/mL to preserve curative potential.

0.5–1.0 ng/mL:
Salvage radiation remains beneficial but may require combining with androgen deprivation therapy (ADT) for higher-risk cases.

This article discusses the above;
https://ascopost.com/news/march-2023/psa-level-at-time-of-salvage-radiation-therapy-after-radical-prostatectomy-and-risk-of-all-cause-mortality/