Testing to Help Diagnose Prostate CancerWhen doctors feel it is necessary to begin screening a patient for early detection of prostate cancer, the two most commonly utilized tests are digital rectal examinations (DREs) and prostate-specific antigen (PSA) blood tests. During a DRE, the doctor uses a gloved and lubricated finger to physically inspect the prostate gland by way of the rectum. The doctor feels for any abnormal lumps or hard tissues on the rear of the gland, the location where many prostate cancers initially develop. The blood test can be used to measure the level of PSA (a substance linked to the prostate gland) present in the bloodstream. If PSA levels are high, the likelihood that prostate cancer has begun to develop increases greatly.
However, even if both of these tests reveal suspicious results, a diagnosis cannot be made. In order for prostate cancer to be diagnosed, tissue from the prostate must be removed in a biopsy procedure and sent to a pathologist for microscopic testing. Before this occurs, however, some doctors recommend further testing be performed, which may include:
Transrectal ultrasound (TRUS)
This form of diagnostic testing utilizes sound waves. A small probe is inserted into the rectum where sound waves are emitted into the direction of the prostate gland. Much like sonar, the sound waves echo back to the probe and get transmitted to a computer for analyzing. The computer then sculpts an image of the prostate using the data from the ultrasound echoes. From here, doctors can get an image of the prostate to evaluate for abnormalities which may be cancerous.
Typically, a biopsy is necessary for the official diagnosis of any cancer. There are different ways biopsies can be obtained, and transrectal biopsies are very similar to transrectal ultrasounds. In fact, a biopsy sample can often be extracted by the probe in a transrectal ultrasound test, which would then be sent for examination by a pathologist.
This form of biopsy procedure may or may not use an ultrasound probe. Instead of reaching the prostate gland through the rectum, a fine needle is inserted between the scrotum and the rectum to extract prostatic tissue. Like any biopsy, the tissue is examined microscopically for the presence of abnormal cells. If this occurs, the cancer is diagnosed and staged.