PSA Monitoring and Detecting Recurrence

After initial treatment for localized prostate cancer is complete, the next phase in the process is monitoring for a recurrence, or a regrowth of the cancer cells somewhere in your body.

Monitoring for recurrence typically involves PSA testing, which is repeated every 3–6 months for the first 3–5 years, then yearly after that. This may vary based on extent of disease and physician preference.

Why might PSA levels rise after treatment? Some prostate cancer cells might have spread outside the prostate before they could be removed or killed. Over time, these cells may begin to multiply and produce enough PSA that can subsequently be detected by lab tests.

If you previously had surgery, ideally your PSA should be undetectable (below the lab’s minimal threshold level). If you had radiation therapy, you will have a different low point for your PSA (called a “nadir”). PSA is produced by all prostate cells—not just prostate cancer cells—so patients who have had radiation therapy may have normal prostate cells that still make PSA. After radiation therapy, doctors need to look for confirmation from multiple tests because PSA can “bounce” or jump up for a short period, and will later return to its low level. PSA bounces typically occur between 12 months and 2 years following the end of initial therapy.

When to Be Concerned About Rising PSA

Surgery Patients: PSA greater than 0.2 ng/mL. Some doctors may have a lower threshold of concern (as low as 0.1 ng/mL). This will depend on factors such as surgical pathology findings and PSA velocity.

Radiation Therapy Patients: If your PSA is 2.0 ng/mL greater than your lowest reading after treatment (referred to as your “nadir” reading), as measured on 2 consecutive tests.

PSA Doubling Time

The rate at which your PSA rises (and how quickly it doubles) after prostatectomy or radiation therapy is one signal of how aggressive your cancer is and can be useful for determining how aggressively it may need to be treated. A shorter PSA doubling time indicates more aggressive disease.

Research has shown that patients whose PSA doubled in under 6 months (fast) had the most aggressive tumors and were more likely to die from their disease, whereas those with longer PSA doubling times have less aggressive tumors and are less likely to die from their disease.

If your PSA begins to rise, your doctor will first try to determine where the cells producing PSA are located. This involves imaging, such as a CT, MRI, or bone scan. Newer, more sensitive scans (such as a PSMA PET scan) can detect very small areas of cancer, when the PSA level is lower. These are rapidly becoming a “gold standard” to evaluate rising PSA after initial treatment, and are increasingly available at centers across the U.S. Now that doctors can “see” cancers much earlier than with traditional types of imaging, research is ongoing to understand how best to use these scans to inform when and how to begin treatment. Ask your doctor what type of imaging would be right for you.

Your test results may show that your cancer has recurred “locally” or “locoregionally,” meaning in or near the prostate region, or is “metastatic,” meaning that it has recurred outside the prostate area.

Imaging scans may also show no cancer. This is called biochemical recurrence, meaning that the only evidence of cancer recurring is a laboratory value—a rising PSA.

Questions to Ask When Your PSA is Rising After Initial Treatment

• What does it mean that my PSA level is rising?
• What is my PSA level now, and how will we monitor changes over time?
• Am I a candidate for local “salvage” prostatectomy or radiation? Why or why not?
• Should I get an imaging scan to see if the cancer has spread to my bones or other organs?
• Should we add a medical oncologist to my treatment team to gain an additional perspective on treating my disease?
• If you recommend that Iinitiate hormone therapy, how will this benefit me and slow down the growth of the cancer cells?
• When is the optimal time to initiate this treatment? For how long will I need it?
• Should my treatment plan also include androgen receptor pathway inhibitor therapy or docetaxel?
• What are the benefits and drawbacks/side effects of hormone therapy? Are there things that I can do to minimize the side effects?
• How long do the treatment effects of hormone therapy last?
• Should I consider joining a clinical trial?

Whether your cancer has recurred locally OR is metastatic, you have many treatment options to discuss with your doctor.

Last Reviewed: 12/2023