A prostate biopsy is the only way for your doctor to confirm whether you have prostate cancer. Even if prostate cancer is suspected based on the results of the PSA blood test, a physical examination of the prostate (digital rectal examination, or DRE), or magnetic resonance imaging (MRI), a biopsy is needed before moving forward with any prostate cancer treatment. In addition to confirming whether there is prostate cancer present, a biopsy gives your doctor a lot of other useful information. This includes the grade of cancer (how aggressive the tumor is) as well as the extent or volume of cancer (based on the number of biopsy samples that show cancer).
What is a prostate biopsy and how is it performed?
A prostate biopsy involves removing small pieces (typically 12-20 samples) of prostate tissue with a special biopsy needle. These samples are then examined under a microscope to check them for cancer. If you are having a transrectal ultrasound-guided biopsy, your doctor may obtain a urine culture (test) in order to treat any existing infection prior to the biopsy. If your urine culture is negative, your doctor may still prescribe several days of antibiotics around the time of the biopsy. He or she may also recommend a Fleet enema (to clean out the rectum prior to the biopsy) to improve the quality of the ultrasound images. There are several ways that a prostate biopsy is performed:
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Transrectal ultrasound-guided biopsy:
An ultrasound uses high-frequency sound waves to create pictures of the prostate gland. These pictures are used to help guide the prostate biopsy needle. The ultrasound probe is inserted into your backside (rectum) with gel lubrication. After the probe is in the rectum—but before starting the prostate biopsy—your doctor will likely measure the prostate in three dimensions. The doctor will also apply an anesthetic to numb the nerves that run alongside the prostate. Then your doctor will take a series of prostate tissue samples using the biopsy needle which travels through the side of the ultrasound probe. -
Ultrasound-guided transperineal prostate biopsy:
If your urologist elects to use a transperineal approach, the needles are passed through the perineal skin (area between the base of the scrotum and the anus) into the prostate under ultrasound guidance. The main benefit of this approach is that the biopsy needle is not passed through the rectum, which significantly decreases the risk of infection. Prior to passing the biopsy needle through the perineum, your urologist will use an anesthetic on the skin to make the biopsy more comfortable. The doctor will then apply an anesthetic around the prostate the same way as for a transrectal ultrasound-guided biopsy. A transperineal biopsy may not be appropriate for all patients. However, it may be specifically beneficial for patients with a history of infection after a transrectal biopsy, history of prostatitis, inflammatory bowel disease, significant rectal bleeding after a previous prostate biopsy, and/or a previous negative transrectal biopsy with suspicion of an anterior prostate tumor.
When should I get a prostate biopsy?
You should have a prostate biopsy on your doctor’s recommendation, which is typically due to an elevated PSA or an abnormal digital rectal examination (DRE). Additionally, your urologist may recommend a prostate biopsy if your PSA is elevated and a multiparametric MRI (mpMRI) of the prostate shows areas of concern for prostate cancer. There are several clinical trials that suggest that men suspected to have prostate cancer should have an mpMRI prior to undergoing a prostate biopsy. However, insurance coverage and country-specific guidance may or may not make a pre-biopsy MRI feasible.
If an MRI is obtained prior to a biopsy, and there are areas of concern on the mpMRI, your urologist may use this information to perform either a cognitive or MRI-ultrasound fusion-guided prostate biopsy of these specific lesions (plus a standard systematic biopsy). This can be performed with either the transrectal ultrasound-guided or transperineal approach.
What are the risks and side effects of a prostate biopsy?
After your biopsy, common side effects may include the following:
- blood in the urine (in most men, typically resolves in a couple of days)
- blood in the rectum/with bowel movements (most men, typically resolves in a couple of days)
- blood in the semen (in most men, typically resolves in a couple of weeks to months)
- temporary erectile dysfunction (less than 5% of men)
- urinary retention requiring a Foley catheter (about 1% of men)
You should be aware of the risk of infection and call your doctor if a fever persists, especially after taking acetaminophen/NSAIDs. In the weeks after your biopsy, your doctor will schedule a follow-up appointment to review the results of the prostate biopsy and what potential treatment recommendations/follow-up is necessary.