If Prostate Cancer Screening Test Results Aren’t Normal
If the results of early detection tests – the prostate-specific antigen (PSA) blood test and/or digital rectal exam (DRE) – suggest that you might have prostate cancer, your doctor will do other tests, such as a transrectal ultrasound and a prostate biopsy to find out.
Transrectal ultrasound (TRUS)
For this test, a small probe about the width of a finger is lubricated and placed in your rectum. The probe gives off sound waves that enter the prostate and create echoes. The probe picks up the echoes, and a computer turns them into a black and white image of the prostate.
This procedure often takes less than 10 minutes and is done in a doctor’s office or outpatient clinic. You will feel some pressure when the TRUS probe is placed in your rectum, but it is usually not painful. The area may be numbed before the procedure.
TRUS is not used as a screening test for prostate cancer because it can’t always tell the difference between normal tissue and cancer. Instead, it is most often used to look for prostate cancer when a man has symptoms or has an abnormal PSA level or digital rectal exam (DRE). It is also used during a prostate biopsy to guide the biopsy needles into the correct area of the prostate.
TRUS is useful in other situations as well. It can be used to measure the size of the prostate gland, which can help determine the PSA density and may also affect which treatment options a man has. TRUS is also used as a guide during some forms of prostate cancer treatment.
A biopsy is a procedure in which small samples of the prostate are removed and then looked at under a microscope. A core needle biopsy is the main method used to diagnose prostate cancer. It is usually done by a urologist, a surgeon who treats cancers of the genital and urinary tract, which includes the prostate gland.
Using TRUS to “see” the prostate gland, the doctor quickly inserts a thin, hollow needle through the wall of the rectum and into the prostate. When the needle is pulled out, it removes a small cylinder (core) of prostate tissue. This is repeated several times. Most urologists will take about 12 core samples from different parts of the prostate.
Though the procedure sounds painful, each biopsy usually causes only a brief uncomfortable sensation because it is done with a special spring-loaded biopsy instrument. The device inserts and removes the needle in a fraction of a second. Most doctors who do the biopsy will numb the area first with local anesthetic. You might want to ask your doctor if he or she plans to do this.
The biopsy itself takes about 10 minutes and is usually done in the doctor’s office. You will probably be given antibiotics to take before the biopsy and possibly for a day or 2 after to reduce the risk of infection.
For a few days after the procedure, you may feel some soreness in the area and will probably notice blood in your urine. You may also have some light bleeding from your rectum, especially if you have hemorrhoids. Many men notice blood in their semen or have rust-colored semen. This can last for several weeks after the biopsy, depending on how often you ejaculate.
Your biopsy samples will be sent to a lab, where they will be looked at with a microscope to see if they contain cancer cells. If cancer is seen, it will also be assigned a grade. This is often expressed as a Gleason score (or Gleason sum). Most Gleason scores range from 6 to 10 (although they can be lower). The higher your Gleason score, the more likely it is that your cancer will grow and spread quickly.
Getting the biopsy results (in the form of a pathology report) usually takes at least 1 to 3 days, but it can sometimes take longer.
Even when taking many samples, biopsies can still sometimes miss a cancer if none of the biopsy needles pass through it. This is known as a false-negative result. If your doctor still strongly suspects you have prostate cancer (because your PSA level is very high, for example) a repeat biopsy may be needed to help be sure.
Prostate biopsy results are sometimes called suspicious. The pathologist may use terms such as prostatic intraepithelial neoplasia (PIN), atypical small acinar proliferation (ASAP, or just atypia), or proliferative inflammatory atrophy (PIA). Suspicious results mean that the cells don’t look like cancer, but they don’t look quite normal, either. If your biopsy results come back suspicious, your doctor may want to repeat the biopsy.
More information about the possible results of prostate biopsies can be found in the Prostate Pathology section of our website.
Last Medical Review: April 1, 2016 Last Revised: April 14, 2016
- Prostate Cancer Risk Factors
- Can Prostate Cancer Be Prevented?
- Finding Prostate Cancer Early
- What Tests Can Detect Prostate Cancer Early?
- American Cancer Society Recommendations for Prostate Cancer Early Detection
- If Prostate Cancer Screening Test Results Aren’t Normal
- Insurance Coverage for Prostate Cancer Screening
- Additional Resources: Prostate Cancer Prevention and Early Detection
- References: Prostate Cancer Prevention and Early Detection