Diagnosis of prostate cancer

Evidence base

A diagnosis of prostate cancer is confirmed or excluded by taking biopsies from the prostate. The prostate gland is located inferior to the bladder, in the midline with the urethra running though the centre of the gland (Figure 1). It is anterior to the rectum, and the posterior aspect of the prostate can be felt or accessed through the rectum.

Prostate biopsies can be undertaken transrectally or transperineally. The transrectal method is commonly used to obtain prostate biopsies because the prostate is immediately anterior to the rectum and is therefore easily accessible via this route.

A transrectal biopsy of the prostate involves insertion of an ultrasound probe into the rectum, so that the biopsy needle can be inserted through the rectal wall into the prostate. The healthcare practitioner uses the ultrasound probe to guide them to areas of the prostate from which they want to obtain biopsy specimens (Figure 2). The ultrasound is not able to determine areas of cancer, but is used to identify areas of the prostate from which to obtain specimens.

A transrectal biopsy of the prostate involves insertion of an ultrasound probe into the rectum, so that the biopsy needle can be inserted through the rectal wall into the prostate. The healthcare practitioner uses the ultrasound probe to guide them to areas of the prostate from which they want to obtain biopsy specimens (Figure 2). The ultrasound is not able to determine areas of cancer, but is used to identify areas of the prostate from which to obtain specimens.

In the prostate, three glandular zones can be identified: the central, transitional and peripheral zones (National Cancer Institute 2016). Most prostate cancers arise in the peripheral zone (Heidenreich et al 2010, Turner et al 2011). Benign prostatic enlargement affects the transitional zone. Prostate biopsies target the peripheral zone. The prostate is divided into the following regions: right apex, right mid, right base, left apex, left mid and left base. Usually, two biopsy specimens are obtained from each section of the prostate creating a ‘12-core biopsy’ (Figure 2).

Figure 2

The indications for prostate biopsy include elevated prostate-specific antigen (PSA) levels in the blood, identification of abnormal areas on digital rectal examination and active surveillance of low-risk prostate cancer.

Most patients are referred for prostate biopsy following identification of elevated PSA levels in a blood test. PSA levels are elevated in prostate cancer, but they may also be elevated for other reasons, including urinary tract infection, prostatitis, post instrumentation of the urethra, for example urological surgery, post catheterisation, and acute urinary retention.

A digital rectal examination involves inserting a gloved finger into the rectum to feel the posterior prostate through the rectal wall. If digital rectal examination of the prostate reveals areas that feel abnormal, this may indicate the presence of a prostate cancer nodule.

Men who are diagnosed with low-risk prostate cancer often choose to monitor prostate cancer – known as active surveillance – rather than undergo curative treatment immediately. For some men the side effects of treatment, for example sexual dysfunction and incontinence, are more likely to affect their quality of life than the prostate cancer itself.

Active surveillance involves close follow-up of the patient with magnetic resonance imaging scans, repeat blood tests and a repeat biopsy 12 months following diagnosis (National Institute of Health and Care Excellence (NICE) 2014).

Men presenting with signs or symptoms of prostate cancer should be referred urgently to a urology department for further investigation – they should be seen within two weeks of referral. Men who have an abnormal prostate on digital rectal examination or those with an elevated PSA, should be referred for further investigation (NICE 2015).

A prostate biopsy should not automatically be offered to the patient on the basis of serum PSA levels alone (NICE 2014). Healthcare practitioners should provide patients, their partners and carers with information, support and sufficient time to decide whether or not to undergo prostate biopsy.

To help men decide whether to have a prostate biopsy, the healthcare practitioner should discuss their PSA level, digital rectal examination findings, comorbidities and risk factors for prostate cancer. Risk factors include increasing age, black African-Caribbean heritage and history of a previous negative prostate biopsy (NICE 2014). The benefits and risks of prostate biopsy should be discussed, including the increased possibility of a diagnosis of clinically insignificant prostate cancer (NICE 2014).

A prostate biopsy is only undertaken if the result will affect the management or treatment of the patient. Therefore, it is not routine practice to perform prostate biopsies on older men who would be unlikely to undergo treatment for prostate cancer (Turner et al2011). In patients who present with signs or symptoms of metastatic disease, a biopsy is required only when the patient is to be included in a clinical trial (NICE 2014).

Written informed consent should be obtained from the patient before the procedure (Turner et al 2011). Prostate biopsy is associated with a risk of morbidity and mortality (Turner et al 2011). Most men will expect mild haematuria, rectal bleeding or haematospermia (blood in the semen), because the prostate is likely to bleed after the procedure.

Since the biopsy needle is passed through the rectum into the prostate, rectal pathogens may cause infection; hence the need to administer prophylactic antibiotics. If there is significant bleeding, the patient may develop clot retention – where blood clots form in the base of the bladder and stop the flow of urine – and may require a catheter. Occasionally, swelling of the prostate may obstruct the flow of urine, causing urinary retention.

The following risks should be discussed with the patient before informed consent is obtained (Turner et al 2011):

• Discomfort.
• Haematuria, haematospermia and rectal bleeding.
• Urinary tract infection, prostatitis, orchitis and septicaemia.
• Clot retention and urinary retention.
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• Learning Points

1. Risk factors for prostate cancer include increasing age, black African-Caribbean heritage and history of a previous negative prostate biopsy.
2. The patient should be positioned in the left lateral decubitus position when a digital rectal examination of the prostate is undertaken.
3. Following the procedure, the patient should be assessed for any complications and advised to rest at home for a few hours, drink plenty of fluids and attend the emergency department if there are signs of infection or inability to pass urine.
4. Risks associated with prostate biopsy include: discomfort; haematuria, haematospermia and rectal bleeding; urinary tract infection, prostatitis, orchitis and septicaemia; clot retention and urinary retention.

Disclaimer: please note that the information provided by RCNi Learning is not sufficient to make the reader competent to perform the task. All clinical skills should be formally assessed at the bedside by a nurse educator or mentor. It is the nurse's responsibility to ensure their practice remains up to date and reflects the latest evidence.

Useful resources

• Greene D, Ased A, Kinsella N, Turner B (2015) Transrectal Ultrasound and Prostatic Biopsy: Guidelines and Recommendations for Training. British Association of Urological Surgeons/British Association of Urological Nurses, London.
• Turner B, Aslet P (2011) Nurse practitioner-led prostate biopsy in the United Kingdom. Urologic Nursing. 31, 6, 351-353.

References

Heidenreich A, Bolla M, Joniau S et al (2010) Guidelines on Prostate Cancer. http://uroweb.org/wp-content/uploads/Prostate-Cancer-2010-June-17th.pdf (Last accessed: April 6 2017.)

National Cancer Institute (2016) Zones of the Prostate. https://training.seer.cancer.gov/prostate/anatomy/zones.html (Last accessed: April 6 2017.)

National Institute of Health and Care Excellence (2014) Prostate Cancer: Diagnosis and Management. Clinical guideline No. 175. NICE, London.

National Institute of Health and Care Excellence (2015) Suspected Cancer: Recognition and Referral. NICE Guideline No. 12. NICE, London.

Turner B, Aslet P, Drudge-Coates L et al (2011) Transrectal Ultrasound Guided Biopsy of the Prostate. Evidence-based Guidelines for Best Practice in Health Care. European Association of Urology Nurses, Arnhem.