How Is Prostate Cancer Diagnosed?

Here’s what doctors look for when diagnosing the most common cancer in men.

Loading the player...

Even though prostate cancer is the most common cancer in men, most men do not die from it. That’s because prostate cancer grows very slowly, which makes it easier to treat.

The prostate is a gland that makes fluid that’s part of semen. The prostate is below the bladder and forms a ring around the urethra (the tube through which urine comes out). Prostate cancer happens when normal cells in the prostate gland become abnormal and then grow out of control. Learn more about prostate cancer here.

Detecting Prostate Cancer Early: Symptoms + Screenings

“The most common symptom of prostate cancer is no symptoms at all,” says William K. Oh, MD, chief of hematology and medical oncology at Mount Sinai Health System. Prostate cancer doesn’t often show symptoms because the growing tumor doesn’t push against anything in the body (which is often the cause of symptoms or pain), so the disease can be silent for many years.

If prostate cancer does cause symptoms, a person might: 

    • Need to urinate more often than usual

    • Have a urine stream that is slower than usual

    • Or have blood in their urine

“In fact, most of the time when we diagnose prostate cancer it’s because a blood test—a PSA blood test—is abnormal,” says Dr. Oh.  

A prostate-specific antigen (PSA) test measures the amount of prostate-specific antigen in the blood. 

Most men without prostate cancer have PSA levels under 4 nanograms per milliliter (ng/mL) of blood. Men with a PSA level between 4 and 10 have about a 1 in 4 chance of having prostate cancer. If the PSA is more than 10, the chance of having prostate cancer is more than 50 percent, according to the American Cancer Society.

Another way doctors detect prostate cancer is by performing a digital rectal exam (DRE). During this exam, the doctor puts a gloved, lubricated finger into the rectum to feel the prostate gland. 

A PSA test or DRE won’t tell you if you have prostate cancer, but the results from these tests are often the first trigger, says Dr. Oh. “In that situation, a patient may be referred to a urologist to do a biopsy of his prostate.”

Diagnosing Prostate Cancer: Further Testing

If your doctor suspects that you might have prostate cancer, he or she may ask you about any symptoms you may be feeling or certain risk factors you may have, such as a family history of prostate cancer. Learn more about risk factors of prostate cancer here.  

Your doctor may also order more diagnostic tests, such as: 

  • Biopsy. During a biopsy a doctor will take a small sample of tissue from the prostate. Then another doctor will look at the sample under a microscope to see if it has cancer. “[A biopsy] is the only way we can be definitively sure that he actually does have prostate cancer,” says Dr. Oh. 

  • Ultrasound, MRI scan, or other imaging tests. These tests take images of the inside of the body and can show abnormal growths.

“If you do have prostate cancer, almost always the treatments are very effective—if the cancer is confined to the prostate,” says Dr. Oh. “Many advances have been made—in both surgical and radiation treatments in the past few years—to make the quality of life better than it was 10 or 20 years ago.”