What is prostate?
The prostate is a walnut sized gland that is part of the male reproductive system. This is located just under the urinary bladder and in front of the rectum. It makes some of the fluid that nourishes and protects sperm cells in the semen. Just behind the prostate are the seminal vesicles, which make most of the fluid for the semen. Urethra is the thin tube that runs through the prostate and carries the urine and semen out of the body through the penis.
The activity and growth of the prostate is stimulated by male hormones called androgens, mainly testosterone secreted by testis
What is prostate cancer?
Prostate cancer is the most common cancer in men in the UK and represented 26% of all male cancers in England and Wales in 2010. It is estimated that nearly 40,000 new cases of prostate cancers are diagnosed in the United Kingdom each year. Prostate cancer is not usually an aggressive cancer and is slow to develop over many years. This means symptoms may not be noticed until it is at a more advanced state. Symptoms can include:
✱ Increase in frequency of urination.
✱ Waking up in the night to pass waters.
✱ Urgency – when you got to go, you got to go.
✱ Hesitancy – once one goes to the toilet, it takes time for the stream of urine to start.
✱ Incomplete emptying
✱ Poor stream
However, these symptoms just mean that the prostate is enlarged and are commonly sign of benign enlargement of prostate called BPH.
What are the risk factors?
Age – most cases are diagnosed after the age 50. Eighty percent of the prostate cancer are diagnosed in men above the age of 65.
Ethnic background – cases are more common in men from African-Caribbean or African descent
Family History – Prostate cancer that runs in a family, called familial prostate cancer, occurs about 20% of the time. This type of prostate cancer develops because of a combination of shared genes and shared environmental or lifestyle factors. .Hereditary prostate cancer, meaning the cancer is inherited, is rare and accounts for about 5% of cases.
Life Style: Unhealthy eating habits, lack of exercise and obesity
What is PSA (Prostate Specific Antigen) testing?
It is a simple and commonly used blood test to help in the diagnosis of prostate cancer. It is measured in ng/ml. Normal value depends on the age and size of the prostate. As a rule of thumb, levels of less than 3ng/ml is considered normal under the age of 60. This level increases by approximately 1ng/ml per decade. So, a level of 5ng/ml may be normal for someone between 71 and 80 years of age.
However, PSA can rise with other problems like prostatitis (inflammation of prostate) and BPH (benign enlargement of prostate). Prostate cancer can sometime be found with lower PSA levels but this is not common. Similarly, not all men with raised PSA have prostate cancer.
What is PCA3 testing?
PCA3 is a urine test and it stands for prostate cancer gene 3. Prostate cells have PCA3 genes that makes the cells produce a small amount of a particular protein which is increased in prostate cancer and secreted in the urine. It’s usage is not standard practice in the NHS but it is available in some private hospitals and clinics.
PCA3 is not a screening test and is usually conducted when the PSA levels are found to be high but clinically the prostate feels benignor when the biopsy turns out to be negative. This is not a fully recommended clinical practice at present.
A digital rectal examination (for prostate massage) is carried out before taking the urine sample. The urine sample is then sent to the laboratory for analysis.
TRUS Biopsy
Trans Rectal Ultrasound Guided biopsy is a commonly carried out procedure under local anaesthetic to take tissue sample from the prostate gland. The term “guided” here implies guiding into the prostate gland. Generally speaking 12 cores are taken systematically through the back of the prostate.
There are risks associated with TRUS biopsies which include infection, Bleeding, urinary retention, blood in urine, blood in semen etc. The frequency of any such event depend on the techniques, experience, precautions taken and experience of individual carrying out such biopsy. The risks can be minimised but cannot be completely removed.
Template Biopsy
Template biopsy is termed as such due to an external template guide used to biopsy the entire prostate so that the tumour in any part of the prostate is not missed. An ultrasound guide is used here as well but the biopsies are taken through the perineum (area behind the scrotum). Procedure is carried out under general anaesthetic.
This is usually carried out if the TRUS (conventional trans-rectal ultrasound guided) biopsies are negative and there is continued suspicion of prostate cancer. The trend is however changing towards carrying out multiparametric MRI scan to guide the decision.
Targeted Biopsy
This procedure can be carried out both transrectal or transperineal depending on the local expertise and practice. The decision is however based on the multiparametric scan (please see the details in MpMRI scan section). Once the scan shows the area in which possible tumour has been identified, the biopsy can be carried out using one of the following methods:
- Cognitive: Based on the scan report and map from it, your urologist will sample a particular area, even though the actual tumour is not visualised on ultrasound scan.
- Fusion biopsy: Images from the MpMRI scan are loaded into the ultrasound machine and a computer software overlaps the suspicious area in a live ultrasound image which can then be targeted with the biopsy needle.
- MRI guidance: This is probably the most accurate way of sampling but has several practical and logistical issues which significantly limits it’s widespread use. The time taken to carry out this procedure inside the MRI scanner makes the procedure very expensive to use, not to mention the practical difficulties of having everything required made of non-ferrous material. Some studies have shown that fusion biopsy provides comparable result to this.