If you’ve had robotic prostate surgery and your latest blood test shows a detectable PSA, it’s understandable to wonder whether this means your cancer has returned. In most cases, however, one detectable result is not enough to answer that question on its own.
Your specialist will look at when your PSA was measured, whether it is falling, stable or rising, and what your prostatectomy pathology showed. This helps determine whether you simply need another PSA test or whether further investigation or treatment should be considered.
What Should Happen to PSA After Robotic Prostate Surgery?
After robotic prostate surgery, your PSA should usually fall to a very low or undetectable level because your prostate has been removed. Your first PSA test is generally performed from around six weeks after surgery, although the exact timing can vary between follow-up programmes.
Your doctor will then use your PSA results to monitor you over time. The results are important for detecting any possible remaining or returning cancer.
What Does a Detectable PSA Actually Mean for You?
A detectable PSA means your blood test has found some PSA after your prostate has been removed. This can understandably be concerning, but the result needs to be interpreted in the context of when it was measured and how it changes over time.
Your doctor will look at your PSA level and how it changes over time. A very low, stable result may be less concerning than a PSA that continues to rise on repeated tests.
Does a Detectable PSA Mean Your Cancer Has Returned?
Not necessarily. If you have a detectable PSA after surgery, one result does not automatically mean your cancer has returned.
Your doctor will usually repeat the test and look at how your PSA changes over time. If your PSA stays very low and stable, you may simply need continued monitoring, while a consistent rise may increase concern about remaining or recurrent cancer.
What Is Persistent PSA After Radical Prostatectomy?
Persistent PSA means your PSA does not become undetectable after surgery. In research studies, persistent PSA is commonly defined as a PSA of around 0.1 ng/mL or higher at approximately 6 to 8 weeks after radical prostatectomy, although definitions can vary.
This is different from your PSA becoming undetectable and then rising later. Your specialist will look at your PSA pattern, pathology results and other cancer features to decide what the result means for you.
Can PSA Be Tested Too Soon After Surgery?
Yes. If your PSA is tested very soon after surgery, the result may not yet provide a reliable picture because PSA takes time to fall after the prostate has been removed.
If your first result is detectable, your doctor may repeat the test after an appropriate interval. This gives you a more reliable indication of whether your PSA is genuinely remaining detectable.
When Does a Rising PSA Become Biochemical Recurrence?
Biochemical recurrence generally refers to a confirmed rise in PSA after treatment, even if you feel completely well and scans do not show visible cancer. After radical prostatectomy, the exact PSA threshold used to define recurrence can vary between guidelines and clinical settings.
Your doctor will look at repeated PSA results rather than one reading. Definitions differ between guidelines; for example, the American Urological Association defines biochemical recurrence after prostatectomy as a PSA of at least 0.2 ng/mL followed by a confirmatory value above 0.2 ng/mL. NICE places emphasis on the pattern of serial PSA results rather than using a single PSA rise alone to determine whether treatment should change.
Is 0.1 ng/mL PSA After Surgery a Cause for Concern?
A PSA of 0.1 ng/mL after prostate surgery deserves review, but its significance depends on when the test was performed and whether the level subsequently falls, remains stable or rises. Your doctor will consider when the test was done and whether your PSA is falling, stable or rising.
If your PSA continues to increase on repeat tests, your specialist may investigate further. The trend is often more important than a single detectable result.
What If Your PSA Is Detectable but Below 0.1 ng/mL?
If your PSA is below 0.1 ng/mL, such as 0.01, 0.02 or 0.05 ng/mL, an ultrasensitive test may be detecting a very small amount of PSA that needs to be interpreted as part of a pattern rather than in isolation.
Your doctor will look at your results over time, along with your cancer grade and surgical pathology. A stable, very low PSA may be interpreted differently from a result that consistently rises on repeat tests.
How Can Different PSA Patterns Be Interpreted After Surgery?
| PSA Pattern | What It May Mean |
| Very low or undetectable PSA after surgery | This is the expected pattern after radical prostatectomy because most PSA-producing prostate tissue has been removed. |
| PSA of around 0.1 ng/mL or higher at approximately 6 to 8 weeks | This may be described as persistent PSA, although definitions vary. Your specialist will interpret it alongside your pathology and subsequent PSA results. |
| Detectable PSA below 0.1 ng/mL on an ultrasensitive test | A very small detectable value does not by itself confirm recurrence. The trend over repeated tests and your individual cancer features are important. |
| PSA that becomes undetectable and later rises | This may indicate biochemical recurrence, although the definition and treatment threshold can vary between guidelines and individual circumstances. |
A PSA result should therefore be interpreted as part of a pattern rather than in isolation. Your specialist will consider the timing of the test, previous PSA results and your prostatectomy pathology before deciding whether monitoring, imaging or treatment is appropriate.
Why Is the PSA Trend More Important Than One Result?
One PSA result only shows your level at that moment. Your doctor gets a clearer picture by comparing your results over time and seeing whether your PSA is stable or consistently rising.
Small changes can occur because of assay variation, so your specialist will consider the overall trend rather than focusing on one minor increase. Ask what your PSA pattern means for you based on your previous results and surgery findings.
Why Does PSA Doubling Time Matter?
PSA doubling time is how quickly your PSA level doubles. A shorter PSA doubling time can be associated with a greater risk of disease progression than a PSA that rises more slowly.
Your doctor will use several PSA measurements to estimate how quickly your PSA is rising. NICE recommends calculating PSA doubling time from a minimum of three measurements taken over at least six months if biochemical relapse occurs. Your cancer grade, stage, pathology and other risk factors will also be considered when deciding what the result means for you.
Does Your Prostatectomy Pathology Affect What PSA Means?
Yes, your pathology report helps your doctor understand what a detectable PSA may mean after surgery. It provides important information about your cancer and your individual risk of recurrence.
- Grade Group: Your final Grade Group helps show how aggressive your prostate cancer may be.
- Cancer Stage: Your pathology shows whether the cancer was contained within the prostate or had spread beyond it.
- Surgical Margins: Positive margins may increase your risk of recurrence, although they do not confirm that cancer remains.
- Lymph Nodes and Seminal Vesicles: Involvement of these areas can influence how your doctor interprets a detectable or rising PSA.
Your doctor will assess these pathology findings alongside your PSA level and how it changes over time. This combined information can help determine whether you need continued monitoring, further tests or treatment.
Do Positive Surgical Margins Explain a Detectable PSA?
A positive surgical margin means cancer cells were found at the edge of the removed prostate. This can increase your risk of recurrence, but it does not prove that cancer has been left behind.
You can also have a rising PSA despite negative margins. Your doctor will therefore consider your margin status alongside your PSA trend, pathology and other cancer features.
Will You Need a Scan If Your PSA Becomes Detectable?
Not necessarily. If your PSA is only slightly detectable, your doctor may first repeat the test and monitor the trend rather than arranging a scan immediately.
If your PSA continues to rise, your specialist may consider a PSMA PET/CT to look for recurrent cancer. A negative scan does not always mean there is no cancer, as very small areas may still be too difficult to detect.
When Might Salvage Radiotherapy Be Considered?
Salvage radiotherapy is treatment you may receive after prostate surgery if your PSA suggests that prostate cancer may remain or has returned. It is usually directed at the area where your prostate was removed.
If biochemical relapse is confirmed after radical prostatectomy and there is no evidence of metastatic disease, salvage radiotherapy may be offered to the prostate bed. NICE recommends radical radiotherapy in this situation. The aim is to treat microscopic cancer cells that may remain in the area even when they are too small to be seen on a scan.
Is Earlier Salvage Radiotherapy Better?
Evidence indicates that salvage radiotherapy is generally more effective when it is given at lower PSA levels, although the decision about when to start treatment should be individualised. However, a single tiny detectable PSA does not automatically mean you need radiotherapy.
Your specialist will consider your PSA trend, pathology and overall risk before recommending treatment. The aim is to treat you at the right time rather than treating every detectable result or waiting until the PSA becomes much higher.
Evidence Note
The 2024 AUA/ASTRO/SUO salvage therapy guideline concluded that salvage radiotherapy after radical prostatectomy is generally more effective when given at lower PSA levels. It recommends delivering salvage radiotherapy at a PSA of 0.5 ng/mL or below when treatment is being considered, while selected patients at higher risk of progression may be offered treatment at PSA levels below 0.2 ng/mL. These thresholds come from international guidance and should not be used to decide treatment without considering your pathology, PSA trend and individual risk.
Could You Need Hormone Therapy as Well?
You may need hormone therapy, also called androgen deprivation therapy (ADT), alongside salvage radiotherapy. Adding ADT to salvage radiotherapy may improve progression-free outcomes in appropriately selected patients.
Your specialist will consider your PSA trend, cancer grade, pathology and overall risk before recommending it. If hormone therapy is suggested, you should also understand possible effects such as hot flushes, tiredness and reduced sexual desire.
Research Insight
The GETUG-AFU 16 randomised trial followed 743 men receiving salvage radiotherapy after prostatectomy. At 10 years, progression-free survival was about 64% in men who received radiotherapy with short-term goserelin compared with 49% in those who received radiotherapy alone. This supports adding short-term hormone treatment for appropriately selected patients, but it does not mean that every man with a detectable PSA needs androgen deprivation therapy.
How Often Will Your PSA Be Checked After Surgery?
Your PSA will be checked regularly after surgery to monitor you for any signs of recurrence. Your specialist may check it more often during the first few years and less frequently if your results remain reassuring.
Your schedule may change if your PSA is detectable or your cancer has a higher risk of recurrence. Even if your early results are undetectable, you should continue long-term PSA monitoring because recurrence can sometimes occur years later.
UK Guidance Note
NICE recommends checking PSA no earlier than six weeks after radical treatment, then at least every six months for the first two years and at least once a year thereafter. If biochemical relapse occurs, NICE advises assessing the PSA trend and doubling time rather than changing treatment simply because PSA has risen. NICE also advises against routinely offering hormone therapy for biochemical relapse alone unless there is symptomatic local progression, proven metastatic disease or a PSA doubling time of less than three months. For people with biochemical relapse after radical prostatectomy and no known metastases, NICE recommends offering radical radiotherapy to the prostate bed.
What Questions Should You Ask About a Detectable PSA?
If you have a detectable PSA, ask whether your previous PSA was undetectable and whether the new result is a meaningful change. You can also ask when your PSA should be repeated and what rise would be considered significant.
Ask how your pathology, including your grade, margins and stage, affects your risk. If treatment is being discussed, ask whether you need imaging and what the benefits and possible side effects would be for you.
Should You Seek a Specialist Opinion About Your PSA?
If your PSA remains detectable or starts rising, speaking with a prostate cancer specialist can help you understand what the result means for you. This can be especially useful if you are considering further tests or treatment.
A specialist review can also help you understand the timing of further PSA tests and how the potential benefits and side effects of additional treatment apply to your individual situation.
Myth vs Fact
| Myth | Fact |
| Any detectable PSA means that prostate cancer has definitely returned. | A detectable PSA does not automatically confirm recurrence. The timing of the test, PSA level, repeated trend and your prostatectomy pathology all need to be considered. |
| A PSA of 0.1 ng/mL means you automatically need radiotherapy. | A PSA around this level at an appropriate postoperative testing interval deserves specialist review, but treatment decisions depend on whether PSA persists or rises and on your individual recurrence risk. |
| A negative PSMA PET/CT proves there is no remaining cancer. | PSMA PET/CT is less likely to detect very small areas of cancer when PSA is low. A negative scan therefore cannot completely exclude microscopic recurrence. |
| Positive surgical margins mean that cancer was definitely left behind. | Positive margins increase the risk of recurrence, but they do not prove that residual cancer remains. Some men with positive margins continue to have undetectable PSA, while recurrence can also occur with negative margins. |
Key Takeaways
- PSA should usually become very low or undetectable after radical prostatectomy, but one detectable result does not automatically mean your cancer has returned.
- Persistent PSA and biochemical recurrence are not exactly the same: persistent PSA never becomes undetectable, while biochemical recurrence commonly refers to PSA rising again after initially falling.
- Your PSA trend, doubling time, pathology, surgical margins, Grade Group and cancer stage are more informative than one isolated PSA result.
- PSMA PET/CT may help locate recurrent cancer, but very small areas can remain undetected when PSA is low.
- Salvage radiotherapy may be more effective when appropriately selected patients are treated while PSA remains relatively low.
Frequently Asked Questions
1. Should Your PSA Be Undetectable After Robotic Prostate Surgery?
Your PSA should usually fall to a very low or undetectable level after your prostate has been removed. However, the timing of your test matters, and a small detectable result does not automatically mean your cancer has returned.
2. Does a Detectable PSA Mean Prostate Cancer Has Returned?
Not necessarily. Your doctor will look at whether your PSA is stable, falling or consistently rising, alongside your pathology results and other risk factors.
3. What Is Persistent PSA After Prostate Surgery?
Persistent PSA means your PSA remains detectable after surgery rather than falling to an undetectable level. In research studies, it is commonly defined as a PSA of around 0.1 ng/mL or higher at approximately 6 to 8 weeks, although definitions vary.
4. Is a PSA of 0.1 ng/mL After Surgery Concerning?
A PSA of 0.1 ng/mL should be discussed with your doctor, but one result does not confirm recurrent cancer. Your specialist will consider when the test was performed and whether your PSA changes on repeat testing.
5. What If Your PSA Is Below 0.1 ng/mL?
A very low PSA, such as 0.01, 0.02 or 0.05 ng/mL, should be interpreted as part of your overall PSA trend. Ultrasensitive tests can detect tiny amounts of PSA that may not have the same significance as a consistently rising result.
6. What Is Biochemical Recurrence After Prostate Surgery?
Biochemical recurrence refers to a confirmed PSA rise after treatment that may indicate recurrent prostate cancer, even when you have no symptoms or visible disease on scans. The exact PSA threshold used can vary between guidelines and clinical settings.
7. Will You Need a PSMA PET/CT If Your PSA Is Detectable?
Not necessarily. If your PSA is very low, your doctor may repeat the test and monitor the trend first, while a consistent or significant rise may lead to consideration of a PSMA PET/CT.
8. What Is Salvage Radiotherapy?
Salvage radiotherapy is radiation treatment given after prostate surgery when your PSA suggests that microscopic prostate cancer may remain or may have returned. It is usually directed at the prostate bed and may be considered while your PSA is still low.
9. Could You Need Hormone Therapy With Salvage Radiotherapy?
You may need hormone therapy, also called androgen deprivation therapy (ADT), alongside salvage radiotherapy if your risk of recurrence is higher. Your specialist will consider your PSA trend, pathology, cancer grade and other factors before recommending it.
10. Should You See a Prostate Cancer Specialist About a Detectable PSA?
If your PSA remains detectable or starts rising, discussing the result with a prostate cancer specialist can help you understand what it means. Your specialist can review your PSA pattern and pathology and explain whether monitoring, imaging, salvage radiotherapy or hormone therapy may be appropriate.
Final Thoughts: Understanding a Detectable PSA After Robotic Prostate Surgery
A detectable PSA after robotic prostate surgery does not automatically mean that your prostate cancer has returned. Your specialist will consider your PSA level, how it changes over time, your pathology results and other risk factors before deciding whether you need further monitoring, imaging or treatment.
If you are considering robotic prostate surgery in London and would like specialist advice, you can contact our team at Prostate Clinic London to discuss your treatment options and arrange a consultation tailored to your individual needs.
References:
- National Institute for Health and Care Excellence (NICE) (2021) Prostate cancer: diagnosis and management. Available at: https://www.nice.org.uk/guidance/ng131
- Ploussard, G., Fossati, N., Wiegel, T. et al. (2021) ‘Management of persistently elevated prostate-specific antigen after radical prostatectomy: a systematic review of the literature’, European Urology Oncology, 4(2), pp. 150–169. Available at: https://pubmed.ncbi.nlm.nih.gov/33574012
- Morgan, T.M., Boorjian, S.A., Buyyounouski, M.K. et al. (2024) ‘Salvage therapy for prostate cancer: AUA/ASTRO/SUO guideline part I: introduction and treatment decision-making at the time of suspected biochemical recurrence after radical prostatectomy’, The Journal of Urology, 211(4), pp. 509–517. Available at: https://pubmed.ncbi.nlm.nih.gov/38421253
- Carrie, C., Magné, N., Burban-Provost, P. et al. (2019) ‘Short-term androgen deprivation therapy combined with radiotherapy as salvage treatment after radical prostatectomy for prostate cancer (GETUG-AFU 16): a 112-month follow-up of a phase 3, randomised trial’, The Lancet Oncology, 20(12), pp. 1740–1749. Available at: https://pubmed.ncbi.nlm.nih.gov/31629656
- Wu, Q., Bates, A., Guntur, P., Shamim, S.A. and Nabi, G. (2024) ‘Detection rate of PSMA PET using different ligands in men with biochemical recurrent prostate cancer following radical treatment: a systematic review and meta-analysis of prospective studies’, Academic Radiology, 31(2), pp. 544–563. Available at: https://pubmed.ncbi.nlm.nih.gov/37770370
- Guy’s and St Thomas’ NHS Foundation Trust (2025) Prostate cancer surgery follow-up. Available at: https://www.guysandstthomas.nhs.uk/health-information/prostate-cancer-surgery-follow-up
- NHS (2025) Treatment for prostate cancer. Available at: https://www.nhs.uk/conditions/prostate-cancer/treatment