Commentary by Dr. Donald Greig
We continue the theme in November of Prostate Cancer Awareness Month by looking at prostate cancer screening options and the latest comparative studies
Prostate cancer screening is a critical area of ongoing research and debate, particularly regarding the efficacy of various testing methods, including the PSA (prostate-specific antigen) blood test, DNA blood tests, and MRI scanning. Each of these methods has its strengths and limitations in detecting prostate cancer, and understanding their sensitivities, specificities, and overall effectiveness is crucial for guiding clinical practice.
PSA Blood Test
The PSA test measures the level of prostate-specific antigen in the blood. Elevated PSA levels can indicate the presence of prostate cancer, but they can also result from benign conditions such as benign prostatic hyperplasia (BPH) or prostatitis.
Sensitivity: The PSA test is sensitive in detecting prostate cancer; however, it is not specific. Many men with elevated PSA levels do not have cancer, leading to potential overdiagnosis and overtreatment.
Specificity: The specificity of the PSA test is relatively low, meaning that a significant number of false positives can occur. This can result in unnecessary biopsies, which carry risks and can cause anxiety for patients.
Overall, while the PSA test can be a useful initial screening tool, its limitations necessitate the use of additional diagnostic methods to confirm the presence of cancer.
DNA Blood Tests
Emerging DNA blood tests aim to detect prostate cancer by identifying specific genetic markers associated with the disease. These tests can provide information about the likelihood of cancer presence and aggressiveness.
Sensitivity and Specificity: DNA blood tests generally show improved specificity compared to PSA tests, as they are designed to target specific mutations or markers associated with prostate cancer. However, their sensitivity can vary based on the specific test used and the population being screened.
These tests represent a significant advancement in prostate cancer diagnostics, as they can help stratify risk and guide decisions regarding further invasive testing.
MRI Scanning
MRI (Magnetic Resonance Imaging) has become an increasingly important tool in the evaluation of prostate cancer. It is particularly useful for visualizing the prostate and surrounding tissues.
Sensitivity: MRI is highly sensitive for detecting clinically significant prostate cancer. It can identify lesions that may not be detectable through other methods, including digital rectal exams or PSA testing.
Specificity: The specificity of MRI can be high, especially when used in conjunction with targeted biopsies. However, there can still be instances of false positives, where benign conditions may mimic cancerous lesions.
MRI is particularly advantageous as it provides a non-invasive visualization method, helping to guide biopsy procedures and treatment planning.
Conclusion
In conclusion, while the PSA blood test has been a cornerstone of prostate cancer screening, its limitations highlight the need for complementary testing methods. DNA blood tests offer promising improvements in specificity, while MRI provides valuable imaging capabilities that enhance cancer detection and treatment planning.
As research continues to evolve, the integration of these technologies may lead to more personalized screening strategies, ultimately improving outcomes for men at risk of prostate cancer. It is essential for healthcare providers to stay informed about these advancements and engage in shared decision-making with patients regarding their screening options.
Article by Eleanor Hayward
Thousands of lives could be saved if the NHS overhauled “dangerously outdated” guidelines that stop men getting tested for prostate cancer, landmark research has concluded.
A coalition of Britain’s leading prostate cancer specialists has written a statement calling for GPs to start proactively offering high-risk men blood tests that can help detect the disease, in a “significant milestone”.
The simple test measures levels of prostate-specific antigen (PSA), a protein which can be elevated in men with prostate cancer.
Under current guidelines, doctors are told not to raise the subject of PSA tests unless men have cancer symptoms. Men aged over 50 without symptoms can request a test for free on the NHS, but the responsibility lies with them to initiate it and book a GP appointment. Experts say this means too many men are in the dark about whether or not they have the disease, as prostate cancer often does not cause any symptoms for several years. Prostate cancer is the most common cancer in men, with 52,000 cases and 12,000 deaths each year in the UK. Unlike breast and bowel cancer, there is no NHS screening programme for those without symptoms. This means about half of prostate cancer patients are diagnosed at a late stage, when it has already spread and is hard to treat. |
The PSA blood test can be used alongside other measures to detect signs of prostate cancer
The use of PSA tests is controversial in medicine, as they have historically been seen as too unreliable and flawed to be rolled out as a routine screening tool, as three quarters of men with a raised PSA do not have cancer, and 1 in 7 men who do have cancer will have a normal PSA result.
However, a new paper argues that improvements in technology mean the balance has now tipped in favour of offering some men blood tests, as those with raised levels will be sent for accurate MRI scans to confirm a diagnosis and to determine whether treatment is necessary.
The “PSA consensus statement”, published in the British Journal of General Practice, was written by a panel of 15 prostate cancer experts and backed by the charity Prostate Cancer UK.
It argues that from now on GPs should “proactively discuss” the PSA blood test with black men over the age of 45, and men with a family history of prostate cancer — groups who are twice as likely to get the disease. More should be done to ensure all men over 50 feel empowered to request a PSA test, it argues.
Amy Rylance, the head of improving care at Prostate Cancer UK, said: “It’s been clear for some time that NHS guidelines which prevent GPs from raising the subject of prostate cancer are dangerously outdated and deeply unfair to the men who face double the risk of getting the disease.
“Leaving men in the dark about their risk means too many men are getting diagnosed with incurable prostate cancer, and this disproportionately affects black men and men living in deprived areas.
“Now, the UK’s leading urologists, clinicians, and researchers are joining our call to change these rules and finally enable healthcare professionals to initiate life-saving conversations with the men at highest risk and give them a choice to have a simple, free PSA blood test.
“Updating NHS prostate cancer guidelines could drive forward significant progress in just a year and, crucially, would give men a fairer chance of living longer.”
The charity said that updated guidelines could be implemented within 12 months, meaning men would be proactively offered PSA tests for the first time from next year.
The guidance would help to bridge the gap to the first ever national screening programme, which researchers are devising via a landmark £42 million trial, called Transform. This trial will assess different screening methods, including DNA tests and PSA tests, to find the best method to screen for the cancer, with the aim of cutting deaths from the disease by 40 per cent.
 Tony Collier’s prostate cancer was not diagnosed until it was already incurable ‘I thought it was just a runner’s groin strain’ When Tony Collier visited a doctor about pain in his groin, he thought it was just a sports injury caused by running. It turned out to be incurable stage four prostate cancer. Collier’s cancer had been there undetected for several years and had he been offered a PSA test by his GP the cancer might have been caught while it was still curable. Collier, from Altringham, has contributed to the new guidance aiming to overhaul NHS procedures in the hope of saving the lives of men in his position. He said: “I was diagnosed with advanced prostate cancer in 2017 after speaking to a sports injuries doctor about what I thought was just a runner’s groin strain. “Unfortunately, it turned out to be far more serious, and the pain was caused by cancer which had spread extensively to my bones. I was originally given just two years to live and was told at the time that I could have had the cancer for 10 years already without having any symptoms. “I’ve been lucky that new treatments mean I’ve been able to keep the cancer at bay and have now far outlived my original prognosis. That’s why I’m so determined to give back and have worked hard over the years to raise awareness and hopefully save lives by getting more men diagnosed earlier. “I’m so proud to have been part of such an important project. If I’d known to have spoken to my GP about it earlier and had that conversation, it might have saved me, and I hope this leads to a change in guidance so all men can have those sorts of lifesaving conversations.” |
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