Causes and Diagnoses

Causes and Diagnoses of Prostate Cancer

The exact cause of prostate cancer is unknown, but certain factors can increase your risk of developing this type of cancer. Risk factors include:
  • Age: Men 50 and older are at a higher risk of prostate cancer
  • Race: Prostate cancer tends to be more common in African-American men and less common in Asian-American and Hispanic men than Caucasian men
  • Family history: There appears to be a genetic component to prostate cancer. If your father or brother has prostate cancer, your risk of developing it is higher
  • Poor diet: Men who eat an unhealthy diet high in high-fat dairy products and meat tend to be at increased risk of prostate cancer
  • Obesity: Obesity has been linked to a higher rate of a more aggressive type of prostate cancer
  • Chemicals in the workplace: Men who are in contact with toxic chemicals at work may have a higher risk for prostate cancer

Screening for Prostate Cancer

The following tests are used to screen for prostate cancer:

  • Prostate-specific antigen (PSA) test: This is a blood test that indicates the level of PSA in the blood. A higher PSA level indicates a greater chance that prostate cancer is present. However, a PSA test alone cannot be used to diagnose prostate cancer. The results of this test will help your physician determine whether additional testing, such as an MRI or biopsy, is necessary.
  • Digital rectal exam: In this exam, the healthcare provider inserts a lubricated, gloved finger into the rectum to feel the prostate for abnormal areas.

Expert groups agree that routine screening for prostate cancer can help detect the disease at an early stage. The age to begin screening depends on your risk of prostate cancer, which is influenced by a combination of factors, including:

  • Age
  • Family history
  • Race
  • Lifestyle

It is important that men discuss the test with their physician to develop a screening plan tailored to their individual risk.

Prostate Biopsy

Abnormal results on screening tests may mean you have prostate cancer, but these tests alone can’t diagnose prostate cancer. A prostate biopsy is needed for a definitive diagnosis. During a biopsy, a small piece of prostate tissue is removed and sent to a lab to check under a microscope for abnormal cells.

Transrectal ultrasound-guided (TRUS) biopsy is the most common type of biopsy for prostate cancer. The procedure takes about 10 minutes and is often done in a urologist’s office. During the biopsy:

  • The area near your prostate is numbed with anesthetic.
  • An ultrasound probe is put into the rectum. This uses sound waves to create images on a computer. It helps guide the healthcare provider as to where to take the small pieces of tissue from your prostate.
    • In some cases, men will undergo MRI prior to biopsy. MRI provides a more detailed picture of the prostate, and the MRI and ultrasound images can be combined to help identify suspicious areas.
  • Using the images as a guide, your physician inserts a thin, hollow needle through the wall of the rectum to take samples from the prostate. A typical biopsy will sample the right and left side of the prostate six times.
  • Antibiotics are typically prescribed to reduce the risk of complications due to infection after the procedure.

After the procedure, you might have soreness in the area, blood in your urine or semen, and bleeding from your rectum.

Transperineal biopsy is another form of biopsy in which a needle is placed through the perineum (skin behind the testicles). As with transrectal biopsy, samples are taken and sent to the lab for review.

Prostate Cancer Diagnosis

To diagnose prostate cancer, pathologists typically first examine the biopsy for abnormal, cancerous cells. Cancer cells look different than normal prostate cells, and an experienced pathologist can very reliably make this diagnosis. If the pathologist sees cancer, the next step is to determine its aggressiveness. This is based on the extent of the cancer (how many biopsy cores contain cancer) and the grade of the cancer (how aggressive each cell looks under the microscope).

If the biopsy confirms you have prostate cancer, your physician may also order additional tests to determine if the cancer has spread. These may include:

This process is called staging, and it will help guide your treatment selection.