What Is a Prostate Biopsy?
A prostate biopsy is a procedure in which your doctor removes samples of suspicious tissue from the prostate to test for cancer. The prostate is a small, walnut-shaped gland in men that produces fluid to nourish and transport sperm. If results from a blood test or digital rectal exam suggest the possibility of prostate cancer, your doctor may recommend a prostate biopsy.
During a prostate biopsy, a needle is used to collect several tissue samples from your prostate gland. The tissue samples are examined under a microscope for cell abnormalities that may indicate prostate cancer. If cancer is present, the biopsy helps determine how aggressive it might be and guides the best treatment options.
This type of cancer is very common, but it often doesn’t cause problems or is easily treated in most men. A prostate cancer diagnosis cannot be confirmed without a biopsy.
What Is the Function of the Prostate Gland?
The prostate is located below the bladder and in front of the rectum. It is a walnut-shaped gland that surrounds part of the urethra, the tube that carries urine and semen out of the penis. The prostate produces fluid that contains sperm produced in the testicles.
During ejaculation, it prevents urine from entering the semen. However, if the prostate becomes too large, it can block the flow of urine through the urethra and out of the penis.
When Is a Prostate Biopsy Necessary?
A prostate biopsy is recommended in the following situations:
If your PSA test shows higher-than-normal levels for your age.
If your doctor finds lumps or other abnormalities during a digital rectal exam.
If you have had a previous prostate biopsy with normal results but still have high PSA levels.
If a previous biopsy revealed abnormal but non-cancerous prostate tissue cells.
If your blood test shows elevated levels of prostate-specific antigen (PSA), or an abnormal lump is detected during a digital rectal exam, your doctor may recommend a biopsy. During a digital rectal exam, your doctor inserts a finger into your rectum to check for prostate enlargement or lumps. Before a biopsy, another option is an ultrasound, where a small probe is inserted instead of a finger to capture images of the prostate.
In patients with rising PSA levels but negative biopsy results under ultrasound guidance, MRI-guided prostate biopsy may be used. It can also be used when diagnostic prostate MRI reveals a very small abnormality that cannot be easily targeted with ultrasound. An MRI-guided biopsy may improve the ability to detect prostate tumors that may require treatment.
How to Prepare for a Prostate Biopsy
To prepare for your prostate biopsy, your doctor may request the following:
Provide a urine sample to check for a urinary tract infection. If you have a UTI, your biopsy will likely be postponed while you take antibiotics to clear the infection.
Stop taking medications that can increase the risk of bleeding, such as warfarin, aspirin, ibuprofen (Advil, Motrin IB, etc.), and certain herbal supplements, several days before the procedure.
Perform an at-home enema before your biopsy appointment.
Take antibiotics before the biopsy to help prevent infection.
How Is a Transrectal Prostate Biopsy Performed?
You will be asked to lie on your side with your knees pulled to your chest. In some cases, you may be asked to lie on your stomach. After cleaning the area and applying gel, your doctor will gently insert a thin ultrasound probe into your rectum.
Transrectal ultrasound uses sound waves to create images of your prostate. Your doctor will use these images to determine where to inject a numbing agent to reduce discomfort during the biopsy. Ultrasound images are also used to guide the biopsy needle into place.
Once the area is numbed and the biopsy device is positioned, your doctor will use a spring-loaded needle to take thin, cylindrical tissue samples. Each time the needle takes a sample, you may feel a brief sensation of discomfort. The doctor may target a suspicious area for the biopsy or take samples from different parts of your prostate. Typically, 12 tissue samples are collected. The entire procedure usually takes about 20 minutes.
The tissue samples are sent to a pathology lab to be examined under a microscope. Results may take about a week. If cancer is found, you will be given a Gleason score. The higher your score, the more likely your cancer will grow and spread quickly, requiring more aggressive treatment.
Risks of a Prostate Biopsy
The risks associated with a prostate biopsy include:
Bleeding at the biopsy site. Rectal bleeding is common after a prostate biopsy.
Blood in your semen. It is common to notice red or rust-colored semen after a prostate biopsy, which indicates the presence of blood. This is not a cause for concern. Blood in the semen may persist for several weeks after the biopsy.
Blood in your urine. This bleeding is usually mild.
Difficulty urinating. A prostate biopsy can sometimes cause difficulty urinating after the procedure. In rare cases, a temporary urinary catheter may be needed.
Infection. In rare cases, a prostate biopsy can cause an infection in the urinary tract or prostate that requires antibiotic treatment.
After the Prostate Biopsy Procedure
Your doctor will likely advise you to engage in only light activities for 24 to 48 hours after your prostate biopsy.
Your doctor may also recommend taking antibiotics for a few days. You may experience the following:
Mild pain and some light rectal bleeding.
Blood in your urine or stools for several days.
A red or rust-colored tint to your semen caused by small amounts of blood. This may persist for a few weeks.
Call your doctor if you experience:
Fever, difficulty urinating, prolonged or heavy bleeding, or worsening pain.
Prostate Biopsy Results
A pathologist, a doctor specializing in diagnosing cancer and other tissue abnormalities, will evaluate your prostate biopsy samples. The pathologist can determine if the tissue is cancerous and estimate how aggressive the cancer might be if present. Your doctor will explain the pathologist’s findings to you.
Your pathology report may include the following:
A description of the biopsy sample. Sometimes called a gross description, this part of the report may assess the color and consistency of the prostate tissue.
A description of the cells. Your pathology report will describe how the cells appear under a microscope. Prostate cancer cells may be referred to as adenocarcinoma. Sometimes, the pathologist finds abnormal cells that are not cancerous. Terms used to describe these non-cancerous conditions include “prostatic intraepithelial neoplasia” and “atypical small acinar proliferation.”
Cancer grading. If the pathologist finds cancer, it is graded on a scale known as the Gleason score. Gleason scoring combines two numbers and ranges from 2 (non-aggressive cancer) to 10 (very aggressive cancer), but the lower end of the scale is rarely used. Most Gleason scores assigned to prostate biopsy samples range from 6 to 10. A score of 6 indicates low-grade prostate cancer. A score of 7 indicates intermediate-grade prostate cancer. Scores of 8 to 10 indicate high-grade cancer.