Prostate Cancer

Diagnosis

Most often, prostate cancer diagnosis relies on screening tests, because the cancer typically does not produce symptoms in its early stages. In fact, about 40 percent of prostate cancer cases aren't detected until the cancer has spread beyond the prostate gland.

Screening tests are often part of a routine physical exam, especially in men over age 40. Your doctor may also recommend screening tests because of symptoms pointing to a prostate problem. Screening tests include:

• Digital Rectal Exam (DRE) — The doctor gently inserts a gloved, lubricated finger into the patient's rectum and by pressing against the rectal wall can feel the back wall of the prostate gland. About 70 percent of cancerous tumors develop near the outer portion of the prostate and can be detected through a DRE.
• Prostate-Specific Antigen (PSA) Test — A sample of blood is analyzed for PSA, a substance produced in the prostate gland that helps liquefy semen. A small amount of PSA always circulates in the blood. High PSA levels, or levels that rise over time, could indicate prostate inflammation, enlargement, or cancer.
• Biopsy — Depending on the result of a digital rectal exam and/or PSA, the doctor may recommend a biopsy. Small tissue samples from several different areas of the prostate are removed — usually using a needle inserted through the perineum, located between the scrotum and anus. A doctor administers a local anesthetic to minimize any pain and discomfort. The tissue is then examined under a microscope for the presence of cancerous cells. A biopsy is usually done in the clinic as an outpatient procedure and generally does not require hospital admission.
• Grading and Staging — If cancer cells are found, doctors will determine how quickly the cancer is growing and whether it has spread beyond the prostate. Additional blood or imaging tests may be necessary to determine the extent of the cancer.
• Bone Scan — Currently, this test is the most effective imaging procedure to determine the spread of cancer to bone. A low-grade radioactive solution is injected into a vein and is selectively taken up or absorbed by areas of new or rapid bone growth, possibly indicating cancer. The need for a bone scan test depends on a man's prostate cancer type and stage.
• Ultrasound — This test is generally performed in conjunction with prostate biopsy. Sometimes, prostate cancer can appear different from normal prostate tissue. The best way to determine the presence of prostate cancer is the combination of digital rectal exam, PSA level, and biopsied tissue.
• Chest X-ray — An X-ray can indicate if the cancer has spread to the lungs. Although less than 5 percent of prostate cancer spreads this far, lung cancer develops in about 25 percent of men with advanced prostate cancer.
• Computed Tomography (CT) Scan — CT scans are most useful when combined with other tests. A CT scan can show abnormal lymph nodes in the pelvis and abdomen where prostate cancer tends to spread. But the test is not sensitive enough to identify microscopic or individual cancer cells in lymph nodes. CT scans, at this time, do not provide reliable enough information about the condition of the prostate or the stage of prostate cancer.
• Magnetic Resonance Imaging (MRI) — Magnetic resonance imaging does not require radiation. It produces a detailed, three-dimensional picture of the body that can detect the spread of cancer to lymph nodes and bone and is better suited for detecting cancer in soft tissues than a CT scan and some other imaging tests. During a specialized form of MRI, called endorectal coil MRI, part of the device is inserted into the rectum to discern details that may determine if the cancer has spread beyond the prostate.
• Lymph Node Biopsy (lymphadenectomy) — During this surgical procedure, a urologist removes some of the nodes near the prostate and examines them under a microscope. The procedure typically takes place during prostate removal surgery, but not always. If other tests, such as a bone or CT scan, show the cancer has spread, this procedure usually is not needed. Lymph node biopsy is most often used to confirm test results indicating the cancer is confined to the prostate, and is part of prostate cancer staging.

If the doctor suspects a patient may have prostate cancer, additional prostate-specific antigen (PSA) and digital rectal exam (DRE) tests are usually performed. A biopsy can help determine a cancer's extent and aggressiveness.