The prostate is a male reproductive organ located just below the bladder with the rectum sitting directly behind it. The prostate’s main function is to produce part of the ejaculation (seminal fluid) which carries the sperm which is made by the testes to the female for fertilisation. In younger men the prostate is about the size of a walnut. The prostate is like a doughnut surrounding the urethra (the tube that conveys urine from the bladder to the penis). The nerves that control erections surround the prostate.
Benign Prostatic Hyperplasia (BPH) or enlargement is common in men as they get older. Some enlargement of the prostate is usual in most men from age 50 onwards. If the enlargement is sufficient to squeeze the urethra, which passes through the prostate, difficulties with urination may occur. Treatment of BPH may require medications or an operation to widen the urethral passage such as a transurethral resection of the prostate (TURP).
It is a non cancerous condition and symptoms include:
Although early prostate cancer has NO SYMPTOMS, locally advanced prostate cancer can have similar symptoms.
Each year in Australia, close to 3,300 men die of prostate cancer – equal to the number of women who die from breast cancer annually, making prostate cancer the second largest cause of male cancer deaths, after lung cancer. Almost one man in eleven will develop prostate cancer during his lifetime with around 20,000 new cases diagnosed in Australian every year.
The known risk factors for prostate cancer include:
Prostate cancer occurs when cells of the prostate reproduce far more rapidly which is unregulated and uncontrolled causing a swelling or tumour. However, unlike BPH, prostate cancer cells can eventually break out of the prostate and invade distant parts of the body, particularly the bones and lymph nodes, producing secondary tumours, a process known as metastasis. Once the cancer escapes from the prostate, treatment is possible but “cure” becomes less likely.
Prostate cancer is usually one of the slower growing cancers. What is complicated with prostate cancer is that some cancers grow very slowly and don’t threaten life, whilst others grow rapidly and do pose a threat. Prostate cancer is often encountered in men over 70, and some of these men die of other causes before their prostate cancer can kill them. This led to the saying “most men die with, not of, prostate cancer”. However, this is not entirely true and the reasons are:
Prostate cancer can be cured if detected early and treated while still confined to the prostate gland. Early detection is the key to enabling better outcomes and potential cure of prostate cancer. The tests for prostate cancer are the prostate specific antigen (PSA) blood test and the digital rectal examination (DRE). These tests do not give a conclusive diagnosis of cancer but can predict the risk of prostate cancer and the need for further investigations such as a prostate needle biopsy.
PSA or Prostate Specific Antigen is a protein that is produced exclusively by the prostate. Its role is to liquefy the seminal fluid to assist in fertilisation. The presence of an elevated PSA result on a blood test can indicate prostate cancer although there are other common causes for a PSA result outside the normal range such as
As a general rule, the higher the PSA result the greater the chance that prostate cancer is present. Where cancer is present, the PSA can predict the volume of disease and likelihood of spread to other organs (metastases). Other PSA parameters that Dr Louie-Johnsun will discuss with you can also give an indication of prostate cancer including PSA velocity (change in PSA over time) and free to total PSA ratio. As a general rule, the higher the PSA result the greater the chance that prostate cancer is present. Newer methods of determining prostate cancer risk and aggressiveness such as Prostate Health Index (PHI) and urinary markers PCA3 can also be discussed with Dr Louie-Johnsun.. Newer methods of determining prostate cancer risk and aggressiveness such as Prostate Health Index (PHI) and urinary markers PCA3 can also be discussed with Dr Louie-Johnsun.
If you have a single elevated PSA reading, Dr Louie-Johnsun will usually suggest a repeat PSA (with free/total ratio) and urine test to exclude infection with abstinence of ejaculation for 72 hours prior to recommending a biopsy or further investigations.
The European Association of Urologists (EAU) has recently updated their guidelines for the detection of prostate cancer (Eur Urol 2013; 64: 347-354) and has made the following statements based on the best available current evidence:-
With the above medical evidence, Dr Louie-Johnsun recommends in accordance with the USANZ 2009 PSA Testing Policy.
Some men, when enquiring about prostate cancer, may be confused by conflicting views expressed about methods of diagnosing and treating the disease. Perhaps the most controversial is the view that it would be better for men not to know whether they have the disease and therefore they should not be tested or treated.
Every man should make their individual choice on whether to be tested for prostate cancer and should initially hold this discussion with their GP
DRE involves inserting a gloved finger in the anus to feel the back wall of the prostate as it lies just in front of the rectum. This gives information about the overall size of the prostate as well as possible tenderness to suggest prostate infection (prostatitis) and most importantly the presence of abnormal nodules, asymmetry and hardness to raise the suspicion of prostate cancer. This assessment must be used together with a PSA as a normal DRE does NOT exclude prostate cancer as the entire gland cannot be palpated via a DRE.
Prostate Needle Biopsy
If there is sufficient suspicion of prostate cancer risk based on DRE and PSA (and sometimes other factors including family history and MRI findings if performed), the definitive procedure to diagnose prostate cancer is a prostate needle biopsy. This involves taking multiple samples of the prostate, which can be done in a few ways:
Worldwide, (and in Australia) this is still the most common method used by Urologists to biopsy the prostate. The procedure is most often performed under local anaesthetic (although it can be performed under general anaesthesia in hospital if requested) with the patient on their side and a small ultrasound probe inserted into the anus to produce an image of the prostate. A systematic biopsy of all areas of the prostate via the rectum is performed and if abnormal areas are detected further biopsies are taken from these areas.
The prostate biopsies will be analysed by a pathologist to determine the grade (severity) and volume of prostate cancer if present. The results will be discussed at the time of your follow up usually 2 weeks after your biopsy.
After the procedure, expect:
Please be aware that all of the above will occur, but will resolve. Usually, you should have 1-2 days off work.
Risks and Complications
Please refer to Dr Louie-Johnsun’s Prostate biopsy information sheet for further information including preparation for your biopsy eg antibiotics schedule.
Recent developments in magnetic resonance imaging (MRI) have improved the ability of MRI to detect tumours, stage cancer and help in management decisions using multiparametric techniques. They are also helping to more accurately target biopsies as detailed above on MRI-Ultrasound Fusion Prostate Biopsy. Dr Louie-Johnsun is finding the benefits of multiparametric MRI particularly in men with previous negative prostate biopsies and a rising PSA, planning surgery or radiotherapy especially in high risk disease and monitoring men on active surveillance.
Please note only widely accepted mainstream treatment options are discussed in this section that have long term proven successful results in the treatment of prostate cancer. Experimental and novel treatments with no long term data are not detailed.
Surgery for prostate cancer is called radical prostatectomy (RP). It involves complete removal of the prostate gland and some of the tissues around it including the seminal veiscles. The primary goal of the surgery is to remove all the prostate cancer whilst maintaining urinary and erectile function as urinary incontinence and erectile dysfunction are the two main long term side effects.
A radical prostatectomy can be done in a number of ways:
Image guided radiotherapy (IGRT) and intensity modulated radiotherapy (IMRT) are two newer external beam radiotherapy techniques that allow the radiotherapy beams to best target the prostate and spare the surrounding normal tissues. Duration of treatment is for five days a week for approximately seven weeks.
IMRT uses dozens of mini-beams of radiation in order to ensure the prostate is completely covered with high doses of radiation whilst minimizing the doses to surrounding normal tissues. IGRT allows the treatment machines (linear accelerators or “linacs”) to target the prostate more accurately. IGRT usually requires insertion of gold seeds (or “fiducial markers”) as a one-off procedure prior to the course of IMRT. The fiducial markers (which can be placed under local anaesthetic transrectally similar to a biopsy) allow the linacs to see where the prostate is before each treatment to ensure the prostate is targeted and normal tissues are avoided. Hormonal therapy immediately before or after radiation is usually a part of the treatment.
This is a more recent development in radiation treatment with radioactive seeds placed directly in the prostate. There are 2 forms of brachytherapy:
For some patients with low volume, low risk prostate cancer it may be reasonable to observe the cancer with serial PSA measurements (blood test), prostate rectal examination (DRE) and periodic prostate biopsies and intervene with curative intent if there is progression of the disease.
Dr Louie-Johnsun strongly advocates active surveillance for appropriate prostate cancer patients. He has presented his cohort of patients on Active Surveillance in state and national meetings and in fact has published one of Australia’s first series on Australian men living with prostate cancer on active surveillance with results confirming minimal anxiety and minimal effects on quality of life.
Not all prostate cancers that are detected are considered to be clinically significant. Active surveillance aims to prevent the overtreatment of clinically insignificant cancersthat may never cause you a problem.
The criteria for active surveillance are yet to be fully defined and validated but generally include low volume, low risk, low grade cancer in patients with a life expectancy of at least 10 years. For example:
IF YOU FALL JUST OUTSIDE THE ABOVE CRITERIA, YOU MAY STILL BE A CANDIDATE FOR ACTIVE SURVEILLANCE. The timing of when to intervene is ill-defined and studies are currently underway to determine what constitutes disease progression and when to intervene.
Advanced prostate cancer is defined as prostate cancer that is not curable and is no longer confined to the prostate. Prostate cancer typically spreads to lymph nodes in the pelvis and to the bones and is more likely with late diagnosis with higher PSAs (eg >20) and higher Gleason Scores (8-10).
Unfortunately surgery and radiotherapy have a more limited role in these situations and often hormonal therapy (androgen deprivation therapy) is needed.
Hormone Therapy (Androgen Deprivation Therapy)
Testosterone is a male sex hormone which helps the prostate and prostate cancer cells to grow larger. Hormone therapy involves stopping the production of testosterone or blocking testosterone from reaching the prostate cancer cells. Historically, reduction of testosterone production required the surgical removal of the organs that produce testosterone i.e. the testicles (orchidectomy) but now the same effect is achieved with medications.
Side Effects of Hormonal Therapy (ADT)
Although not all patients will experience all the side effects, they include:
Treatment with Hormones (ADT)
Hormone therapy can often be used intermittently when the PSA is low and stable known as “intermittent therapy”. However, there can come a time when the prostate cancer cells are no longer responsive to hormonal therapy known as “hormone refractory” or “castrate resistant” prostate cancer. Unfortunately this is when prostate cancer begins to progress and a referral to a medical oncologist is required to consider systemic therapies such as chemotherapy.