A prostate biopsy is a procedure to remove small samples of prostate tissue to be examined under a microscope. See an illustration of the prostate gland.
For a prostate biopsy, an ultrasound probe is inserted through the rectum (‘transrectal ultrasound’) and needles passed (‘transrectal biopsy’). The biopsy samples are examined under a microscope for cancer cells.
A biopsy may be done when there is a suspicion that prostate cancer is present e,g. after a blood test shows a high level of prostate-specific antigen (PSA) or after a rectal examination reveals an abnormal prostate or a lump.
Why have a prostate biopsy?
Biopsies are taken to find the cause for:
- a high PSA or PCA3 score
- because the prostate feels abnormal
- abnormal findings on transrectal ultrasound or MRI
Once biopsies are taken, it may be be possible to determine the severity of cancer, if it is found. This enables a decision on how to treat prostate cancer if it is present.
How do I prepare for prostate biopsies?
It is important to let the nurses and doctors know of the following:
- allergies to latex, drugs or medicines
- current medications or drugs (antibiotics, blood thinning agents or anticoagulants, e.g. warfarin, aspirin, clopidogrel or herbal remedies)
- Have had bleeding problems (e.g. after dental treatment).
Please also do the following:
- Stop aspirin and clopidogrel (Plavix) at least 5 and preferably 10 days before the procedure
- Stop anti-inflammatory medications such as ibuprofen, Advil, Nurofen, Voltarol, Arthrotec, three days before the biopsy
You will need to sign a consent form that says you understand the advantages, risks and alternatives of a prostate biopsy and agree to have the test done.
Let us know about any concerns you have regarding the need for the test, its risks, or how it will be done.
How are prostate biopsies performed?
One hour before the procedure is planned, you will take an antibiotic (ciprofloxacin 750 mg) by mouth with water. You will be asked to take off all of your clothes and put on a hospital gown. Usually, the procedure takes place in the outpatient department. Just before the prostate biopsy samples are collected, a very small needle will be placed in an arm vein and an antibiotic (gentamicin) given. These antibiotics are to prevent infection.
You will be asked to lie on your left side. Your prostate may be re-examined with a finger in a glove. Then, an ultrasound probe is passed up the anus. This can sometimes be uncomfortable as the anus is sometimes stretched by the probe. The prostate is examined by ultrasound and local anaesthetic is injected around the prostate to allow the biopsies to be taken comfortably. Transrectal ultrasound (TRUS) is used to guide the needle to the correct biopsy location. Biopsies are taken with a spring-loaded needle. The needle enters the prostate gland and removes a tissue sample quickly, but is quite loud and makes a snapping sound as a biopsy is taken.
How does it feel to have biopsies taken from the prostate?
You may feel a slight sting when you receive an injection of local anaesthetic, which rapidly fades. You may feel a dull pressure as the ultrasound probe is placed in the rectum and when the biopsy needle is inserted. As local anaesthetic is use, it is usually painless. Rarely, you also may feel a brief, sharp pain as the biopsy needle is inserted into the prostate gland. Usually several biopsy samples are collected over 5 minutes. Finally, an antibiotic suppository (metronidazole, Flagyl) in placed in the rectum.
Following the test, you will be asked to avoid strenuous activities for about 2-48 hours. You may experience some mild discomfort in the biopsy area for 1 to 2 days after the test and may notice some blood in your urine. Also, you may have some discoloration of your semen for up to one or two months after the biopsy. You may experience a small amount of bleeding from your rectum for 2 to 3 days after the test.
However, notify us or a doctor immediately if:
- You have persistent bleeding that fills the toilet bowl
- You feel faint.
- Your pain increases.
- You have a fever higher than 100.4 °F (38 °C).
- You are unable to urinate within 8 hours.
- If you have a general anaesthetic, you will return to your room a few hours after the procedure. You will need someone to drive you home when you are released.
You will need to take antibiotics for five days after the procedure. Usually ciprofloxacin 500 mg is given twice a day.
What are the risks of having a prostate biopsy?
The following problems can occur after prostate biopsies:
- Infection: this can occur in the blood, prostate or urine. Antibiotics taken before and after reduce this risk to a minimum
- Blood in the urine: usually there is no blood, but sometimes there is blood and this can form clots from time to time. If the clots become large, it can sometimes be difficult to pass urine and this may require a return to your doctor
- Bleeding from the rectum. You may experience a small amount of bleeding from your rectum for 2 to 3 days after the test. Contact your doctor if the bleeding persists beyond this time.
The biopsy samples may not contain cancer even though cancer is present in the prostate.
Further biopsies may be necessary at a later date.
Swelling of the prostate after biopsies can make it more difficult to pass urine afterwards, and rarely a catheter may be necessary to empty the bladder.
What do the results show?
Usually, the results are available within 4 days. The following may be found:
- normal prostatic tissue: no infection and no cancer
- prostate cancer
- prostatic intraepithelial neoplasia (PIN): this may or may not go on to prostate cancer and needs further observation
- Inflammation: this indicates that there is a greater chance of developing urinary problems in the future but not necessarily cancer
- ASAP cells that are commonly found if cancer is present, but not true cancerous cells
- Other abnormalities: rarely other findings are made
If cancer cells are present, analysing them can determine how fast the cancer is likely to spread. This analysis is called a Gleason score, which we will discuss with you. Further tests (such as prostate-specific antigen, bone scan, lymph node biopsy, or MRI scan) may be done to evaluate whether the cancer has spread beyond the prostate gland.
What Affects the Test Results?
Test results may be inconclusive if the prostate biopsy sample does not contain enough tissue to make a definite diagnosis.
Because a needle biopsy collects tissue from such a small area, there is a chance that a cancerous growth may be missed.
What to think about?
Normal prostate biopsy results do not rule out cancer.
If the biopsy results indicate cancer, other tests may be needed to determine the extent of the cancer. These tests may include a blood test (prostate-specific antigen), bone scan, lymph node biopsy, or MRI scan.
Not all cases of prostate cancer are treated. There are many factors to consider when deciding on a treatment plan.
A prostate gland biopsy does not cause problems with erections and will not make a man infertile.
What are the alternatives to a prostate biopsy?
Multiparametric MRI is the most promising alternative to prostate biopsies, as these can indicate with reasonable certainty whether high grade disease is present. This needs to be performed in places experienced in prostate MRI. We work with Dr Ali Hassan and Nuada Medical, who have experience with this.
The PCA3 score is the first genetic test for prostate cancer risk. It looks for a gene that is over-expressed in prostate cancer tissue. If the PCA3 score test is positive, there is a higher risk of prostate cancer. To perform the test, the prostate is massaged by a finger placed in the rectum for about 1 minute. The bladder is emptied and the first part of the voided urine is analysed for the PCA3 score. If positive, it indicates a significant chance of prostate cancer being present. Usually, biopsies are still necessary to prove cancer is present. If the PCA3 score is low, then prostate cancer is significantly less likely.
Sometime, it is appropriate not to have a prostate biopsy and just repeat the blood test in case it was an error or just a transient rather than sustained rise in PSA.
Before cancer treatment is planned or given, it is usually essential to have proof of cancer. Usually, this can only be obtained by taking a biopsy. In some situations, it can be possible to make a diagnosis based on other features. These include:
a very high PSA level (having ruled out an infection in the urine or prostate) or PCA3 score
what the prostate feels like when examined with a finger, or how it looks when an MRI or transrectal ultrasound is performed
the presence or absence of abnormalities in the bones when a bone scan or x-ray is performed
Usually, at least two of the three features should be present before a diagnosis of prostate may be made without biopsies from the prostate.