Prostate Cancer

Diagnosing & monitoring

Early-stage prostate cancers typically do not cause symptoms but may be found during routine screening exams, such as a digital rectal exam (DRE) and a prostate-specific antigen (PSA) blood test. Men typically begin prostate cancer screening at the age of 50, although men at high risk are encouraged to discuss screening with their doctor when they’re 40. Several tests are used to diagnose and monitor prostate cancer, including a physical examination of the prostate, blood and urine tests and diagnostic imaging.

Digital rectal exam (DRE)

For this screening exam, the doctor inserts a lubricated, gloved finger into your rectum and feels the prostate through the rectal wall. A DRE enables your doctor to feel for lumps or abnormal areas in the prostate. This exam takes only a few minutes to complete and is usually painless; however, if the prostate is enlarged, you may feel some discomfort.

Prostate-specific antigen (PSA) test

The prostate-specific antigen (PSA) is a protein produced in the prostate gland by both normal prostate cells and cancerous cells. Some of this protein enters the bloodstream, which means that the PSA level can be measured in a small sample of blood taken from a vein in your arm. Generally, higher PSA levels indicate the possible presence of prostate cancer cells, but doctors differ on what they consider an abnormal reading. Sometimes a high PSA level can be explained by a prostate enlarged because of benign (noncancerous) disease or a urinary tract infection. Your doctor may choose to repeat the PSA test before performing more tests, especially if you are not at-risk or experiencing other symptoms.

If prostate cancer is diagnosed, the PSA test is useful for monitoring the status of disease and assessing the effectiveness of treatment. Your doctor will compare your PSA levels over time and watch for an increase, which may indicate that the cancer has progressed.

If you have elevated PSA levels and/or symptoms, or the presence of cancerous cells is confirmed, your doctor may order one or more of the following tests.

Blood tests

The 4K score and Beckman Coulter’s Prostate Health Index (phi) are tests that help determine the risk for prostate cancer in a man with an elevated PSA level. The PCA3 test measures the level of the prostate cancer antigen 3 (PCA3) in the urine. Progensa, an FDA-approved PCA3 test, is often done with PSA testing to determine whether a repeat biopsy is necessary in men who have had negative results on previous biopsies.

Magnetic resonance imaging (MRI)

Magnetic resonance imaging (MRI) is a promising way to see cancer within the prostate. MRI involves the use of high-powered magnetic energy and a computer to create a three-dimensional picture of the prostate and surrounding areas. No radiation is involved, and an MRI can help determine the size, location and extent of any cancer in the prostate.

Transrectal ultrasound (TRUS)

Ultrasound uses sound waves to visualize internal organs and evaluate them for cancer and other conditions. To create an image of your prostate, your doctor may perform a transrectal ultrasound (TRUS), which involves inserting a lubricated ultrasound probe into the rectum (see Figure 1). TRUS is useful for determining the size of the prostate, but its most important function is to guide the needle during a prostate biopsy.

Figure 1


A biopsy is the only way to definitively diagnose prostate cancer. This procedure involves removing cells or tissue for microscopic examination by a pathologist (a doctor who specializes in the diagnosis of disease). A thin, hollow needle is inserted into the prostate through the wall of the rectum. It is then used to remove a small tissue sample. Several tissue samples are usually collected; typically eight to 18 samples are obtained. Taking this many samples helps ensure that the prostate cancer is found. Biopsies are usually performed at the doctor’s office.

Fusion biopsy

This is a new method of biopsy that fuses, or combines, detailed MR images with live, real-time ultrasound images of the prostate. For this type of biopsy, an MRI is done first, and a radiologist notes any suspicious areas on the images. At another appointment, an ultrasound probe is inserted into the patient’s rectum. As the probe moves around the prostate, fusion software shifts an overlaid MR image accordingly, giving the doctor a detailed three-dimensional ultrasound/MRI view. The fused image helps guide the biopsy needles precisely to the suspicious areas.

A fusion biopsy pinpoints the area in question more precisely than a routine biopsy, which may miss cancer cells. Because of this difference, a fusion biopsy may reduce the number of repeat biopsies needed because of inconclusive results.

Other imaging tests

Imaging tests may be used to determine whether prostate cancer has spread to nearby organs (known as “locally advanced” disease), lymph nodes or other sites, or whether it has recurred after treatment.

If prostate cancer spreads, it’s likely to travel first to nearby lymph nodes and then to the bones. Positron-emission tomography (PET) or a ProstaScint scan is sometimes used to detect areas of locally advanced prostate cancer in the lymph nodes. With PET, a very small dose of a radioactive agent is injected into a vein in the arm. The agent is taken up by the cancer and can be seen on the PET images. The ProstaScint scan involves the use of a different radioactive tracer that binds to cancer cells in lymph nodes or other soft tissues.

A bone scan can detect whether prostate cancer has spread to your bones. For this test, a very small amount of radioactive material is injected into a vein in your arm. The material will travel through your bloodstream and collect in abnormal cells in the bones. While you lie on a table, a scanner will detect the radioactive material and create an image of your skeletal system.

Computed tomography (CT) or MRI is used to determine whether the prostate cancer has spread to the lymph nodes. With CT, a computer is linked to an X-ray machine, and detailed pictures of areas inside the body are taken from different angles. A dye (known as “contrast material”) may be injected into a vein in your arm or you may be asked to drink a liquid with dye in it to help the organs or tissues show up more clearly on the images. During MRI, magnets, radio waves and a computer are used to make a series of detailed pictures of areas inside the body. Your doctor may order a chest X-ray, which may be helpful in identifying prostate cancer that has spread to the lungs.

Prediction tools

Prostate cancer prediction tools combine several variables of your prostate cancer and compare them with results from scientific studies involving groups of other men with prostate cancer. These tools then use mathematical algorithms to calculate the probability of certain factors, such as the location of your tumor or the potential success of certain treatments:

  • The Partin Tables are statistical modeling tools used to predict the stage of cancer and whether the tumor is likely confined to the prostate before surgery (prostatectomy). The tables consider data from the PSA blood test, the biopsy-based Gleason score and clinical staging to help predict the odds that the cancer has spread outside the prostate. This can help your doctor assess whether surgery is a potentially curative option for you.
  • Prostate cancer nomograms are sets of diagnostic, predictive tools used to help determine what will happen after treatment, based on different factors of your diagnosis. The patient enters specific clinical features of his prostate cancer, and the tool calculates the probability (percent) of the extent of the cancer and the chances of recurrence after treatment.

These tools are meant to provide supplemental guidance for you and your doctor as you consider treatment options.

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