Prostate Cancer Diagnosis
A definitive diagnosis of prostate cancer is only made by examining tissue under a microscope. While a doctor may suspect cancer on the basis of a digital rectal exam or PSA test, the diagnosis must be made by doing a biopsy. Once prostate cancer has been confirmed, the doctor will determine its grade and stage in order to plan treatment.
Compared with most cancers, cancer of the prostate tends to grow slowly. Decades may pass from the time the earliest cell changes can be detected under a microscope until the cancer progresses enough to cause symptoms.
Like other cancers, a diagnosis of prostate cancer is made only by examining tissue under the microscope. When your doctor suspects prostate cancer -- on the basis of your symptoms, on the results of a digital rectal exam (DRE), and/or on a prostate-specific antigen (PSA) test -- the definitive diagnosis must be made by doing a biopsy.
To get a biopsy, you will go to a urologist, and the procedure will be performed in the doctor's office.
Using a transrectal ultrasound (TRUS) probe, the doctor first images your prostate, then inserts hollow biopsy needles into areas of the gland that feel or look suspicious. Bits of tissue are removed from each site through the needles; each snip causes a sharp sting. If a tissue sample is taken because of an elevated PSA test rather than a suspected abnormal area in the prostate gland, random tissue samples are often taken from six or more sectors of the prostate. This helps establish the size and extent of any cancer. However, even when multiple samples are taken, biopsy can miss some cancers.
A pathologist (a doctor who identifies diseases by studying tissues under a microscope) will look at the biopsied tissue for prostate cancer cells. Once prostate cancer has been diagnosed, the doctor must determine both the stage and grade of the cancer.