How Your Doctor Uses Biopsies to Diagnose Prostate Cancer
A biopsy is the only way to know for sure if you have cancer.
The most common way to take a biopsy of the prostate is by a core needle biopsy. Your doctor uses a transurethral ultrasound as a guide on where to take the biopsy. The biopsy is done by a doctor who specializes in problems in the urinary or genital tract, called a urologist.
Core needle biopsy
Here's what to expect during a core needle biopsy. To take the biopsy, your doctor uses a tool called a transurethral ultrasound (TRUS). This is a tool that allows your doctor to see your prostate gland using special sound waves. If your doctor sees anything that looks unusual during the ultrasound, he or she can take a small piece of tissue called a biopsy.
Preparing for the biopsy. The week before your TRUS and biopsy, you may need to stop taking aspirin and other nonsteroidal anti-inflammatory drugs, such as ibuprofen. They can increase your risk for bleeding during the procedure. You may also need an enema to clean out your rectum. You may be given antibiotics to take before the biopsy and possibly for a couple of days after to lower your risk for infection.
Where and how the biopsy is done. The ultrasound and biopsy can be done in your doctor's office. On the day of the test, you'll lie on your side with your legs tucked up toward your stomach. You won't need to be put to sleep. You will probably get medicine to numb the area around your anus. A doctor inserts a finger-sized probe (the TRUS) into your anus and rectum. The probe sends silent, painless sound waves to your prostate gland. The echoes of the waves bouncing off the prostate allow the doctor to see a picture of your prostate on a computer screen. The picture, called a sonogram, shows your doctor where to place the biopsy needles.
Your doctor will usually take about 12 biopsy samples. A small, fast needle takes small samples from different parts of your prostate. They're small, cylinder-shaped sections. Usually they're about 1 inch by 1/16 inch. The whole process usually takes about 15 minutes.
What to expect after the biopsy. After the biopsy, you may have some soreness in the area and may find a little blood in your urine, semen, or bowel movements. This should go away in a few days or weeks.
About the biopsy results. Once the biopsy is done, a pathologist--a doctor who examines tissue samples in a lab--looks at the tissue under a microscope to check for cancer cells. It usually takes a few days for the results of your biopsy to come back. A biopsy is the only sure way to tell if you have cancer and what kind of cancer it is.
In some cases, a biopsy doesn't find cancer that is present. That's because sometimes the needle misses where the tumors are. When cancer is present but isn't found, it's called a false negative biopsy. Your doctor may recommend another biopsy if he or she suspects the test results are wrong (for example, if the biopsy is negative in a man with a persistently high PSA level).