Prostate cancer prognosis linked to prostate-specific antigen levels below threshold

After treatment for metastatic prostate cancer, a drop in prostate-specific antigen (PSA) levels in the blood is an indicator that treatment is working. A recent real-world study indicates that reaching a PSA level below 0.2 ng/mL is an indicator of improved patient survival. The study is published online in CANCER.

Multiple phase 3 clinical trials have shown that a PSA level below 0.2 ng/mL is the best cutoff for determining a patient’s prognosis. Real-world data are lacking, however, and physicians often use other metrics, such as percentage of PSA decline, to assess treatment response. To determine whether there is a PSA response target associated with the most favorable outcome in community-dwelling adults with metastatic prostate cancer, investigators analyzed Veterans Health Administration data on 4,890 patients who received testosterone deprivation therapy with or without other treatments in 2018–2023 for metastatic hormone-sensitive prostate cancer.

Over a median follow-up of approximately 2 years, 896 patients died. Patients whose PSA levels dropped below 0.2 ng/mL within 9 months of starting treatment were 54% less likely to die than patients whose levels did not drop this low, whether their PSA levels also decreased by at least 90% or not. Patients who had at least a 90% PSA decline but did not achieve a PSA level of less than 0.2 ng/mL had no improvement in survival. The findings suggest that patients who do not experience a PSA drop below 0.2 ng/mL could be candidates for more aggressive treatments. Also, patients who received testosterone deprivation therapy plus another drug to further block testosterone were more likely to reach a PSA level below 0.2 ng/mL.

“These data show that we need to target a PSA below 0.2 ng/mL as our metric of success to optimize outcomes for our patients with metastatic prostate cancer,” said corresponding author Stephen J. Freedland, M.D., professor of urology at Cedars-Sinai and staff physician at the Durham VA Medical Center.

Who’s behind this story?

Gaby Clark

MA in English, copy editor since 2021 with experience in higher education and health content. Dedicated to trustworthy science news.

Full profile →

Alexander Pol

PhD nano-engineering from Delft University. Published researcher and journal reviewer. Brings scientific insight to content standards.

Full profile →