A biopsy of the prostate is a surgical procedure in which (usually) several thin cylindrical “cores” of prostate tissue are removed from the prostate for microscopic examination by a pathologist.
Just click here to watch two brief video presentations.
The first is about when you may need a prostate biopsy;
the second is about what to expect when you have the biopsy.
A biopsy will often be recommended if a digital rectal examination (DRE) reveals a lump or some other abnormality in the prostate. It may also be recommended if a prostate specific antigen (PSA) test suggests the possibility of risk for prostate cancer because of the level of PSA in the patient’s blood (based on his age and other factors).
Please note: There is no such thing as a “normal” PSA level below which a man can not have risk for prostate cancer. Prostate cancer can be found in men with extremely low PSA levels, and as many as 20-25 percent of men will be identified as having cancer in their prostates even if their PSA level is < 4.0 ng/ml.
There are two common ways to perform a prostate biopsy:
- By inserting a series of biopsy needles into the prostate through the wall of the rectum
- By inserting a series of biopsy needles into the prostate through the perineum (the area between the base of the penis and the rectum)
In the United States, the first of these two methods is by far the most common prostate biopsy procedure carried out today.
Before the procedure is performed, the patient may be given a sedative to help him relax; he may be asked to have an enema before the biopsy is carried out; and he will normally be asked to take a short course of antibiotics to prevent any possible infection.
Some urologists now believe that it is wise to take a rectal swab from a patient some time prior to conducting a biopsy so as to ensure that the antibiotic prescribed to prevent infection will be appropriate for that specific patient. Other urologists tend to simply prescribe a quinolone antibiotic as being likely to prevent most potentially common infections.
Specimens of prostate tissue (known as “chips”) extracted from men who are having a transurethral resection of the prostate (carried out as a treatment for benign prostatic hyperplasia) are also commonly examined by a pathologist for the presence of prostate cancer tissue. Strictly speaking, however, this is not a prostate biopsy.
Transrectal Biopsy of the Prostate
Today this procedure is usually carried out in the office of an experienced physician such as a urologist. However, it can also be carried out in a hospital or a day surgery center. It is commonly carried out with the accompanying use of a local anesthetic, but always ask the urologist if he or she is going to give you an anesthetic: prostate biopsy can quite often be painful without it.
The patient is asked to lie in one of several possible positions. The physician normally uses a special prostate biopsy “gun” to drive ultra-fine biopsy needles (about half an inch long and a sixteenth of an inch in diameter) through the wall of the rectum and into the prostate. This gun is used in combination with a transrectal ultrasound “probe,” which enables the doctor to “see” where the biopsy needles are being placed into the prostate. Each hollow needle will remove a fine cylindrical “core” of prostate tissue in about a second.
This entire procedure, properly called transrectal ultrasound-guided prostate biopsy or TRUS-guided biopsy is usually completed in about 20 minutes, from start to finish.
The Number of Cores Removed
Many different theories exist as to the “best” way to “sample” the prostate so as to find any cancer that may be present. There are no “absolute” prostate biopsy guidelines. In general, however, an experienced physician will seek to take prostate biopsy specimens as follows:
- Cores from all major regions of the prostate so as to ensure complete “geographic” coverage
- Cores from any region of the prostate that felt suspicious under digital rectal examination
- Cores from any region of the prostate that may appear suspicious under transrectal ultrasound.
In the 1990s, it was customary to carry out what was known as a “sextant” biopsy, in which six cores were removed from regionally defined areas of the prostate and then additional samples were removed from any additional areas that looked suspicious under transrectal ultrasound or felt suspicious on DRE. More recently, however, it has become normal to extract about 12 biopsy cores from defined regions of the prostate so as to have a greater likelihood of finding any cancer that may be present.
In some patients, defined by specific circumstances, what is known as “saturation biopsy” may be recommended. In a saturation biopsy the physician may remove more like 20-30 biopsy cores during any one biopsy procedure. The merits of saturation biopsy are a matter for discussion, and it would be unusual for any patient to have a saturation biopsy as an initial biopsy.
Similarly, it is now possible to carry out “targeted” biopsies under magnetic resonance imaging or MRI. The cost of MRI-based biopsies is much higher than that of TRUS-guided biopsies. This type of biopsy is not widely used as yet, and (once again) the use of this type of biopsy as an initial biopsy procedure would be unusual outside a research center of some type.
Adverse Effects of a Prostate Biopsy
The majority of men undergo prostate biopsy with few or no significant problems at all. However, some men do have problems, and a good physician will be sympathetic to these problems if they occur:
- While many men have little or no pain associated with a prostate biopsy, for some men there can be significant pain. It is possible that such pain is associated with the biopsy needle cutting into or through nerves that run through the prostate tissue.
- Minor bleeding may occur after a biopsy, and evidence of blood in the urine and the semen post-biopsy is very common. (As an example, many men will have evidence of dark brown, dried blood in their semen for a week or so after a biopsy.) Rectal bleeding is also a possibility. The patient should be encouraged to avoid heavy work or exercise for 24 hours after a biopsy. If there is significant and continued bleeding, a patient should immediately contact the doctor’s office.
- Difficult with urination is also a possible complication. In this case also, the doctor’s office should be informed immediately.
- Infection associated with a prostate biopsy is a relatively rare but very possible complication. If the patient develops a high fever, and complains of chills or abdominal pain after the procedure, he should arrange to see the doctor right away.
Prostate Biopsy and Drug Therapy
Prior to a prostate biopsy, patients should make sure that their urologist is advised of all medications that they are normally taking on a day-to-day basis. Patients who take such drugs as aspirin, warfarin, and clopidogrel (Plavix) — or other so-called “blood thinners” — are normally asked to stop taking such drugs for a period of time prior to a biopsy procedure, and should discuss the appropriate time to stop taking such drugs (and when to restart them after biopsy) with their primary care physician or their cardiologist, as appropriate.