Key learning points:
– Prostate cancer is the most common cancer in men
– Current diagnostic tests for prostate cancer can give false negatives and false positives and are therefore currently unsuitable for a national screening programme
– Men need support to make an informed decision on whether or not to be tested for prostate cancer
Prostate cancer is the most common cancer in men. Every year over 44,000 men are diagnosed with the disease in the UK and it kills more than 10,000. With no national screening programme, diagnosing prostate cancer remains one of the biggest challenges facing health professionals.
Nurses play a vital role in ensuring that all men concerned about prostate cancer are armed with the information they need to make an informed decision about testing.
Signs and symptoms
Most early stage prostate cancers do not cause any symptoms, mostly because either the tumour is small or in the outer part of the prostate and is therefore not putting any pressure on the urethra.
However, the National Institute for Health and Care Excellence (NICE) guideline for Suspected cancer: recognition and referral,1 which was updated in June 2015, recommends that any man presenting with lower urinary tract symptoms (LUTS) (such as nocturia, urinary frequency, hesitancy, urgency or retention), erectile dysfunction (ED) or visible haematuria should be considered for a prostate specific antigen (PSA) blood test and digital rectal examination (DRE) to assess for prostate cancer. These men should be referred using a suspected cancer pathway referral (to recieve an appointment within two weeks) for prostate cancer if their PSA levels are above the age‑specific reference range or their prostate feels malignant on DRE.1
Risk factors
Due to the fact that most men with early stage prostate cancer will not have any symptoms, being aware of a man’s risk is essential. There are three key risk factors to think about:
1. What is the man’s ethnicity?
We know that in the UK one in four black men will be diagnosed with prostate cancer, which is double the risk of a white man (one in eight).
2. Does he have a family history of prostate cancer?
If the man has a father or brother who has been diagnosed with prostate cancer, his risk is two and a half times greater than if he has no affected first-degree relatives. He may also have a greater risk if his mother or sister has been diagnosed with a type of breast cancer that is due to a fault in the genes BRCA1 or BRCA2.
3. How old is he?
Prostate cancer usually affects men over the age of 50, and the risk increases with age. The average age of diagnosis is between 70 and 74 years. However, black men are more likely to be diagnosed at a younger age than white men, therefore should start to think about their risk from the age of 45.
What to do after an assessment?
There is currently no national screening for prostate cancer as there is no clear evidence that screening using current tests brings more benefit than harm. Although it may reduce the number of deaths from the disease, on a population-wide level this is outweighed by the harm it can cause – diagnosing many more men whose cancer is indolent, subjecting them to unnecessary treatment that can impact on their quality of life.
The current first step to diagnosis is the PSA blood test via an informed choice programme, but it is not a definitive test and can only indicate a problem with the prostate. Public Health England’s Prostate Cancer Risk Management Programme (PCRMP) provides information to primary healthcare professionals and men to enable them to decide whether to have the PSA blood test or not.2 After considering the pros and cons and discussing with their GP, men over the age of 50 are entitled to a PSA test if they want one. However, it is essential that they are counselled in the limitations of the test beforehand so that they can make an informed choice. To help men make this decision, there is a shared decision tool available that helps men through the process.3
The pros and cons of the PSA test
PSA is a protein produced by the prostate. It is normal for men to have a small amount of PSA in their blood, and as men get older this amount can rise.
A raised PSA level, above the ‘normal’ value for a man’s age, can be a sign of a problem with the prostate but not necessarily prostate cancer due to the poor sensitivity and specificity of the test. It can produce false positive and false negative results – approximately 76% of men with a raised PSA level do not have prostate cancer on biopsy (false positive), and around 15% of men with prostate cancer on biopsy (and 2% with a fast growing prostate cancer) do not have a raised PSA (false negative).
The benefits of having a PSA test include finding prostate cancer before symptoms develop and diagnosing the cancer at an early stage when it’s more likely it can be successfully treated. Although it may reassure the man if their PSA level is within the normal range for their age, this can also be a limitation as it can miss cancer and provide false reassurance, along with causing unnecessary worry and testing if there is no cancer.
Also the PSA test does not differentiate between slow and fast growing cancers, which can lead to unnecessary treatment and side effects for a cancer that would never cause the man any harm within his lifetime. Therefore, it is imperative to ensure that the man takes into account these pros and cons in the context of his own risk of prostate cancer, and his personal circumstances. For example, if a man suffers from health anxiety, would knowing his PSA level create more or less concern?
Once the man has made an informed choice to have the PSA test, it is important to explain to him that he should avoid vigorous exercise and not ejaculate 48 hours prior to the test. He will also be unable to have the test if he’s had a prostate biopsy within the previous six weeks or a DRE within the previous week before the test. Urinary infection should also be ruled out as this can elevate the PSA level for many months, even after treatment.
Referral to secondary care for further tests
The PCRMP recommends that age-related PSA referral values are used: 3ng/ml and above for men aged 50-59, 4ng/ml and above for men aged 60-69 and above 5ng/ml for men aged 70 and over.
However, the programe also suggests that the serum PSA level alone should not automatically lead to referral to secondary care for a prostate biopsy. Other factors that should be considered in conjunction with the PSA level are prostate size, DRE findings, age, ethnicity, co-morbidities, history of any previous negative biopsy and any previous PSA history. The patient should be involved in any decision about referral to another healthcare provider.
The PCRMP is currently undergoing a review with updated guidance which is expected to be released by the end of 2015.
Biomarkers – the future of prostate cancer testing?
A biomarker can be defined as a measureable characteristic that highlights a difference between two biological states. It can be anything that changes in response to a biological transition (eg a gene, protein, part of a cell). A biological transition can include the change between a healthy cell and cancer cell, as well as a cancer cell before treatment and a cancer cell after treatment.
There are four main types of biomarker relevant to prostate cancer: risk, diagnostic, prognostic and predictive. Risk biomarkers indicate if a man is at a higher than average risk of prostate cancer. Diagnostic biomarkers tell us if a man has prostate cancer or not. Prognostic biomarkers predict the likely outcome for a man who has no treatment, and predictive biomarkers calculate how well a man will respond to prostate cancer treatment.
At present, the PSA blood test is the best method we have of identifying an increased risk of prostate cancer in a man. However, there is current research and clinical trials looking into other ways of testing for prostate cancer and identifying whether the cancer is aggressive or non aggressive. Urine testing for prostate cancer may be a possibility; either as a stand alone test or in combination with PSA testing. Unfortunately the downside to tests that measure proteins in urine is that the amount of protein found varies depending on an individual’s urine concentration so this needs to be taken into account when analysing the results.
The Engrailed-2 (EN2) protein is a patented biomarker for early detection of both prostate and bladder cancers. Early studies investigating this protein have been encouraging, but further larger scale and longer-term clinical studies are required. A large clinical trial called Procure, looking at EN2 as a potential biomarker for prostate cancer, is aiming to complete and publish by Autumn 2016. A total of 500 men with a PSA between 4 and 20ng/ml and no previous history of prostate cancer will be enrolled from the Surrey area.
Another urine test is the prostate cancer gene 3 (PCA3) (Progensa) that detects the amount of PCA3 protein in the urine following prostatic massage. Although it is currently only available in a few UK private hospitals and clinics, it is being assessed by NICE as we need more evidence to see how much PCA3 in the urine denotes prostate cancer.
The prostate health index (PHI) is designed to categorise men (aged 50 and over whose PSA levels are between 2-10ng/ml with negative DRE) into low, moderate and high probabilities of prostate cancer (found on biopsy). A score of 0-20.9 indicates low risk (8.4%) of cancer; 21-39.9 indicates moderate risk (21%) and greater than 40 indicates high risk (44%).
Scientists are also looking into urine testing for a combination of transmembrane protease serine 2 (activated by testosterone) combined with a gene known to have potential to cause cancer – ERG (TMPRSS2-ERG).
Human glandular kallikrein 2 (HK2) is emerging as a potential prostate cancer specific tumour marker. It is found adjacent to the PSA gene and exists in multiple forms in serum and as free and complexed HK2. It is more than 20,000 times more potent than PSA and some evidence suggests it activates and regulates PSA. It is only available privately and ProstateHealth UK – who hold the licence – believes that when incorporated with the PSA test it can provide a more accurate method of detecting prostate cancer.
Conclusion
Prostate cancer diagnosis and screening continues to be one of the most fiercely debated subjects surrounding the disease and gives rise to a number of questions that remain to be answered. For example, with population-based screening currently not recommended in the UK, should we be using our increased knowledge on the risk factors for prostate cancer to streamline individual testing to those men at higher than average risk? Or, on the other hand, should we disregard the PSA test entirely and concentrate on other biomarkers?
Until research gives us the answers we need and a better test becomes available, nurses working in primary care and the community play a critical role in supporting men concerned about prostate cancer, by providing balanced information so they can make an informed choice about the PSA test.
Prostate Cancer UK is a major beneficiary of Movember. This Movember men and women are being encouraged to Grow, Give or Move to raise money and awareness for men’s health. To show your support visit: uk.movember.com/
Resources
Risk factors and PSA:
Prostate Cancer UK – prostatecanceruk.org/prostate-information/are-you-at-riskprostatecanceruk.org/prostate-information/getting-diagnosed/psa-test
Trends Urology & Men’s Health – trendsinmenshealth.com/article/psa-targeting-the-men-at-highest-risk/
Sense about science. Making sense of screening, Second edition 2015 – senseaboutscience.org/pages/making-sense-of-screening.html
Signs and symptoms:
Prostate Cancer UK –prostatecanceruk.org/prostate-information/about-prostate-cancer#signs-and-symptoms
Prostate Cancer UK’s Specialist Nurse’s can be contacted on – 0800 074 8383 (Monday – Friday 9-6pm and Wednesday 10-8pm) or by email – prostatecanceruk.org/get-support/our-specialist-nurses/email-our-specialist-nurses.
References
1. National Institute for Health and Care Excellence. Suspected cancer: recognition and referral. NICE guideline NG12, 2015. nice.org.uk/guidance/ng12 (accessed 26 October 2015).
2. NHS Cancer Screening Programmes. Prostate Cancer Risk Management Programme. cancerscreening.nhs.uk/prostate/ (accessed 26 October 2015).
3. National Health Service. Shared Decision Making, Prostate Specific Antigen (PSA) testing, 2012. sdm.rightcare.nhs.uk/pda/psa-testing/ (accessed 26 October 2015).
