Tests and diagnosis
The following Examinations, tests and procedures are used to detect (find) and diagnose prostate cancer:
- Digital rectal exam (DRE): This is an exam of the prostate via the rectum. The doctor inserts a lubricated, gloved finger into the rectum and feels the prostate through the rectal wall for lumps, hardness of abnormal areas.
- Prostate-specific antigen (PSA) test: This test measures the level of PSA in the blood. PSA is a substance made by the prostate that may be found in an increased amount in the blood of men who have prostate cancer. PSA levels may also be high in men who have an infection or inflammation of the prostate or BPH (a non-cancerous enlargement of the prostate).
- Transrectal ultrasound (TRUS): A procedure in which a probe that is about the size of a finger is inserted into the rectum to check the prostate. The probe is used to bounce high-energy sound waves (ultrasound) off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. Transrectal ultrasound is used during a biopsy procedure.
- Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist. The pathologist will examine the biopsy sample to check for cancer cells and determine the Gleason score. The Gleason score ranges from 2-10 and describes how likely it is that a tumor will spread. The lower the number, the less likely the tumor is to spread. There are 2 types of biopsy procedures used to diagnose prostate cancer.
- Transrectal biopsy: The removal of tissue from the prostate by inserting a thin needle through the rectum and into the prostate. This procedure is usually done using transrectal ultrasound to help guide the needle.
- Transperineal biopsy: The removal of tissue from the prostate by inserting a thin needle through the skin between the scrotum and rectum and into the prostate.
Determining whether prostate cancer is aggressive
When a biopsy confirms the presence of cancer, the next step is to determine the level of aggressiveness (grade) of the cancer cells. In a laboratory, a pathologist examines a sample of your cancer to determine how much cancer cells differ from the healthy cells. A higher grade indicates a more aggressive cancer that is more likely to spread quickly.
The most common scale used to evaluate the grade of prostate cancer cells is called a Gleason score. Scoring combines two numbers and can range from 2 (nonaggressive cancer) to 10 (very aggressive cancer).
Determining how far the cancer has spread
Once a prostate cancer diagnosis has been made, your doctor works to determine the extent (stage) of the cancer. If your doctor suspects your cancer may have spread beyond your prostate, imaging tests such as these may be recommended:
- Bone scan
- Computerized tomography (CT) scan
- Magnetic resonance imaging (MRI)
- Positron emission tomography (PET) scan
Not every person should have every test. Your doctor will help determine which tests are best for your individual case.
Once testing is complete, your doctor assigns your cancer a stage. This helps determine your treatment options. The prostate cancer stages are:
- Stage I. This stage signifies very early cancer that′s confined to a small area of the prostate. When viewed under a microscope, the cancer cells aren′t considered aggressive.
- Stage II. Cancer at this stage may still be small but may be considered aggressive when cancer cells are viewed under the microscope. Or cancer that is stage II may be larger and may have grown to involve both sides of the prostate gland.
- Stage III. The cancer has spread beyond the prostate to the seminal vesicles or other nearby tissues.
- Stage IV. The cancer has grown to invade nearby organs, such as the bladder, or spread to lymph nodes, bones, lungs or other organs.