Prostate-specific Antigen & Prostate Cancer
Prostate cancer is the most common form of cancer in men. In the UK, 1 in every 8 men will be diagnosed with the condition within their lifetime, resulting in around 12’000 deaths per year1. Prostate-specific antigen is a major protease found in semen which functions to cleave semeogelins into smaller polypeptides resulting in the liquefication of semen2.
This week, we had the pleasure of welcoming Dr Floris Helmich, who discussed laboratory imprecision relating to Prostate-specific antigen (PSA) and prostate cancer in our latest webinar. Dr Helmich took the time out of his busy schedule to present his experience in PSA quantification and the importance of quality control in yielding accurate and precise results as well as discussing some of the experimental techniques he has found useful in identifying the source of bias laboratory testing. Dr Helmich also discussed the ambiguity relating to reporting ranges and how bias can affect the results of laboratory PSA testing.
What is PSA?
PSA is an enzyme produced by the prostate ductal and acinar epithelium where it is secreted into the lumen before it is used to liquefy semen. Once PSA enters circulation, most are bound to protease inhibitors, however, some remain inactive and circulate in the lumen as free PSA2.
PSA levels in men vary depending on their age. Typically, men between the ages of 50 and 69 should have a PSA level below 3ng/ml. If the PSA concentration exceeds 3ng/ml, it could be a potential indicator of prostate cancer3. However, the challenge with using PSA as the sole monitoring method for prostate cancer is the relatively high false positive rate associated with it. A higher PSA concentration can also be attributed to conditions such as an enlarged prostate, prostatitis, or a urinary tract infection4.
Research indicates that 1 out of 4 men with elevated PSA levels will actually have prostate cancer. Additionally, it has been observed that approximately one in every seven men diagnosed with prostate cancer will maintain normal PSA levels3. These findings highlight the limitations of relying solely on PSA screening for prostate cancer diagnosis. As a result, some countries have started to limit their recommendations regarding PSA-based prostate cancer diagnosis.
In response to these limitations, other countries have chosen to maintain their recommendations for PSA testing but are augmenting the guidelines by incorporating additional criteria to ensure more accurate diagnoses.
Elevated levels of PSA should not always be automatically interpreted as a sign of prostate cancer. In older men, one common cause of elevated PSA is benign prostatic hyperplasia (enlarged prostate). Additionally, prostatitis, which refers to inflammation of the prostate, can contribute to an increase in PSA concentration3. It’s important to consider other potential factors that can lead to elevated PSA levels, such as urinary tract infections, recent sexual activity, natural age-related increases, or injury to the groin area5.
Therefore, when assessing PSA levels, it is crucial to recognize that various non-cancerous conditions can also result in elevated PSA. It is recommended to consult healthcare professionals who can evaluate the individual’s medical history, perform further diagnostic tests, and consider other clinical factors to accurately determine the underlying cause of elevated PSA and make informed decisions about the next steps in diagnosis and treatment.
Ultra-low PSA concentrations
The diagnostic accuracy of PSA concentration for prostate cancer is known to be limited. However, there is a clear association between PSA levels and prostate cancer, which confirms it as a valuable tool for risk stratification and diagnosis when used in conjunction with other established factors.
PSA testing also plays a crucial role in monitoring patients who have undergone treatment for prostate cancer. In cases where the patient is deemed cancer-free, their PSA levels should decrease to within the normal range. Following radical prostatectomy (removal of the entire prostate), PSA levels should ideally be undetectable. Post-radiotherapy, it is expected that PSA levels will reach their lowest point (nadir) within 12-18 months. However, it’s important to note that in some cases, a temporary spike in PSA concentration has been observed after radiotherapy. This spike should not be immediately interpreted as recurrent cancer, but these patients should be closely monitored.
If PSA concentrations rise above 2.0ng/ml after radiotherapy, further testing is recommended to assess the possibility of recurrent cancer. Close monitoring and additional evaluations will help healthcare professionals make accurate and timely decisions regarding the patient’s ongoing treatment and care6
Different countries offer varying guidance in relation to Ultra-low PSA testing. The table below details some of these recommended guidelines:
|American Urology Association 7||PSA concentrations of >0.2ng/ml, followed by a subsequent confirmatory >0.2ng/ml result should be considered biochemical recurrence. However, a cut-off of 0.4ng/ml may better predict metastatic relapse.|
|European Association of Urology8||A detectable PSA indicating relapse should be differentiated from a clinically meaningful relapse. PSA thresholds that predict further metastasises are:
Post-RP = >0.4ng/ml
Post-RT = nadir + 2ng/ml
|Prostate Cancer Foundation1||Post-RP = PSA 0.2ng/ml is indicative of biochemical recurrence
Post-RT = PSA nadir + 2ng/ml is indicative of biochemical recurrence
Randox Ultra-low PSA Control
We are excited to introduce Randox’s latest innovation, the Ultra-low PSA Control, designed to assist in the precise quantification and monitoring of ultra-low levels of PSA in post-therapy prostate cancer patients. This control has been specifically optimized for use on Roche systems, ensuring exceptional performance and compatibility. Moreover, it is versatile enough to be utilized on various other platforms, making it the sole control available on the market for measuring ultra-low levels of PSA across a range of instruments.
With the Acusera Ultra-low PSA Control, healthcare professionals can achieve accurate and reliable results, enabling them to monitor the progress and treatment response of prostate cancer patients with heightened sensitivity. With a clinically relevant concentration of approximately 0.055ng/ml, this advancement in control technology contributes to enhanced patient care and supports medical professionals in making informed decisions regarding treatment adjustments or further interventions.
Randox’s commitment to innovation and precision in diagnostic solutions continues with the Ultra-low PSA Control, empowering laboratories to deliver high-quality and dependable PSA measurements, even at the ultra-low levels required for post-therapy monitoring.
Take a look at our webinar, Laboratory Imprecision in Relation to PSA and Prostate Cancer Follow-up, with Dr Floris Helmich to learn about how his clinical laboratory deals with bias at quality control relating to Ultra-low PSA quantification
If you’d like to learn more about PSA testing and prostate cancer, we encourage you to read our new educational guide, Ultra-low PSA and Prostate Cancer
If you would like an additional information on our Ultra-low PSA Control, or anything else relating to Quality Control, don’t hesitate to reach out the email@example.com. Additionally, feel free to visit our QC resource hub where you will find all of our brochures, support tools and a collection of educational material, to aid you in maintaining the highest possible levels of quality.
- Prostate Cancer Foundation. About prostate cancer. Prostate Cancer UK. Published 2023. https://prostatecanceruk.org/prostate-information-and-support/risk-and-symptoms/about-prostate-cancer
- Balk SP, Ko YJ, Bubley GJ. Biology of Prostate-Specific Antigen. Journal of Clinical Oncology. 2003;21(2):383-391. doi:https://doi.org/10.1200/jco.2003.02.083
- NHS Choices. Should I have a PSA test? – Prostate cancer. NHS. Published 2019. https://www.nhs.uk/conditions/prostate-cancer/should-i-have-psa-test/
- Isono T, Tanaka T, Kageyama S, Yoshiki T. Structural Diversity of Cancer-related and Non-Cancer-related Prostate-specific Antigen. Clinical Chemistry. 2002;48(12):2187-2194. doi:https://doi.org/10.1093/clinchem/48.12.2187
- Mejak SL, Bayliss J, Hanks SD. Long Distance Bicycle Riding Causes Prostate-Specific Antigen to Increase in Men Aged 50 Years and Over. Steyerberg EW, ed. PLoS ONE. 2013;8(2):e56030. doi:https://doi.org/10.1371/journal.pone.0056030
- Santis D, Gillessen S, Grummet J, et al. EAU-EANM-ESTRO-ESUR-ISUP-SIOG Guidelines on Prostate Cancer.; 2023.
- AUA. Advanced Prostate Cancer: AUA/ASTRO/SUO Guideline (2020) – American Urological Association. www.auanet.org. Published 2023. https://www.auanet.org/guidelines-and-quality/guidelines/advanced-prostate-cancer
- Sindhwani P, Wilson CM. Prostatitis and serum prostate-specific antigen. Current Urology Reports. 2005;6(4):307-312. doi:https://doi.org/10.1007/s11934-005-0029-y
Featured Reagent | Microalbumin
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A urine microalbumin test is a test to detect very small levels of albumin in the urine. This test can detect early signs of kidney damage. Microalbumin tests are recommended for people with an increased risk of kidney disease, such as those with type 1 diabetes, type 2 diabetes or high blood pressure.
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The name Christopher McNally may be one that you already recognise. In 2016 he earned 1st place in the Science category of the Randox Pinnacle Placement Awards, having caught the attention of Senior Management for his pioneering work developing a new diagnostic for pancreatic cancer.
Fast-forward two years and Christopher is now back at Randox as a PhD student, conducting research in prostate cancer as part of the recently-announced Randox-Ulster University PhD Academy.
We sat down with Chris to hear all about his revolutionary prostate cancer project, what motivated him to sign up to our PhD Academy and what it’s like to be back in the place where his scientific career began.
Here’s Chris’ story.
I came into Randox when I was just 19 years old for my third year at university as part of the company’s year-long placement programme. It was a great way to truly experience a working laboratory outside of the classroom and really cemented my desire to work in biomedical science.
I was lucky enough to be placed in the company’s Donegal branch, Randox Teoranta, which is close to where I grew up in Gartan, and offered me the opportunity to carry out ground-breaking medical research surrounded by my home of Donegal.
I would highly recommend the opportunity to perform an industrial placement to anyone. It helps you to prepare for what comes after university, develops your skills in the area in which you are interested, and refines your laboratory techniques. I was delighted to hear I won in the Science Category of the Randox Pinnacle Placement Awards during my time there as well, and this really inspired a confidence in me that I had become a talented scientist even before I graduated.
When I completed my fourth year of studies at Ulster University, I graduated with a degree in Biomedical Science and Professional Practice, and returned to work for Randox. The traits and qualities I learned during my placement had subsequently brought me to post-graduate employment, and I was thrilled. I was lucky enough to be able to walk straight back into the lab knowing exactly what to do and how to do it.
Despite becoming employed within Randox straight out of university however, I had this feeling that I was not finished with regards to academic study. I knew I wanted to do more, to perform more research. So, when I heard about the Randox-Ulster University PhD Academy I really was intrigued. It was the perfect platform to further my studies and be able to give more to the scientific community.
When choosing the area of research for my PhD I was keen to hear more about a collaborative prostate cancer project led by two of Northern Ireland’s leading cancer researchers Dr Mark Ruddock (Randox) and Dr Declan McKenna (Ulster University). From my time at university and my time spent at Randox, I thought I could bring my experience and knowledge in cancer research into this project, so I thought, let’s go for it.
Ultimately, the project involves looking at prostate cancer patients as well as patients who have other non-serious prostate conditions, and recognising any potential differences in the two. We can then develop a clinical diagnostic test that can identify the men at the highest risk of prostate cancer and stratify the patients accordingly.
The earlier we can do this, the quicker a patient can be treated, or not treated as the case may be. Overdiagnosis is a significant problem in prostate cancer care and many men, who do not have prostate cancer, but present with prostate cancer-like symptoms, unfortunately go through invasive, uncomfortable and most importantly, unnecessary procedures.
This work therefore has real potential to improve the management of prostate cancer, which is currently the most common cancer in males within the UK. It’s a very rewarding field to be working in and I thoroughly enjoy the work I’m doing knowing that it will have a real-life impact on many men. I’m very proud to be able to say that my PhD research will really make a difference and I now know for certain that I will continue working in cancer research after my project is complete.
Knowing that I’m helping to improve the quality of patient’s lives brings a great deal of satisfaction that few jobs can replicate and I’m excited to see what the next three years will bring.
We’re very proud of Christopher and the amazing work he is doing in prostate cancer research, and are delighted that he has made the decision to join the Randox-Ulster University PhD Academy.
For more We Are Randox stories about our amazing colleagues, make sure to follow us on Facebook, Instagram and Twitter and follow the hashtag #WeAreRandox.
For current vacancies in our team, visit careers.randox.com
To find out more about the Randox-Ulster University PhD Academy, please email email@example.com