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Prostate Cancer (cont.)

Exams and Tests

A proper medical interview and physical examination are essential in the diagnostic workup of any man in whom prostate cancer is suspected. You may be referred to a physician who specializes in urinary tract diseases (a urologist) or in urinary tract cancers (a urologic oncologist). You will be asked questions about your medical and surgical history, your lifestyle and habits, and any medications you take.

Because the symptoms may indicate a variety of conditions, you will undergo testing to pinpoint their cause. Initial screening tests include the digital rectal examination as well as blood testing for PSA and urine testing for blood or signs of infection.

Blood tests: These are used to detect complications of prostate cancer.

Complete blood cell count: Your hemoglobin level and relative amounts of different blood cells are checked. Anemia is a common sequel to cancers, as are certain other blood irregularities.

Hepatic transaminases: These are enzymes produced in the liver. They are called alanine aminotransferase (ALT) and aspartate aminotransferase (AST). In known prostate cancer, these levels are usually elevated when the cancer has spread to the liver. However, levels of these enzymes can be abnormally high in a number of different conditions that have nothing to do with cancer.

Alkaline phosphatase: This enzyme is found in the liver and in bone. It is a sensitive indicator of both liver and bone cancer.

BUN and creatinine: These measures are used to assess how well the kidneys are working. Levels can be elevated in a number of conditions and may suggest an obstruction.

Prostatic specific antigen (PSA): This is an enzyme produced by both normal and abnormal prostate tissues.

It may be elevated in noncancerous conditions, such as prostatitis (inflammation of the prostate) and benign prostatic hypertrophy (noncancerous enlargement of the prostate), as well as in cancer of the prostate.

PSA values may be more helpful over time in following recurrence of cancer and the response to treatment than in diagnosing a previously unknown cancer.

The following standards have been set for PSA levels:

Less than 4 ng/mL: Normal value

4-10 ng/mL: Either benign disorder or cancer

Greater than 10 ng/mL: Most likely cancer

Less than 0.2 ng/mL: After prostate is surgically removed

Traditionally, a PSA of 4 ng/ml has been used as a cutoff value for deciding for or against doing a prostate biopsy. However, some experts now recommend lowering that to 2.5 ng/ml and performing the biopsy in men who have levels in excess of this threshold. The American Urological Association guidelines (2009) do not define a definite cutoff point but advise that all the other risk factors for prostate cancer be taken into account while making a decision on whether to proceed for a biopsy. One of the important factors that need to be considered is the rate at which the PSA value has increased over time on repeated measurements (PSA velocity).

Imaging studies: These reveal the size and location of the tumor in the prostate as well as the extent of spread of the disease.

CT scan or MRI of abdomen and pelvis: This is the best way to detect the extent of the primary cancer as well as distant metastases.

Chest x-ray film: This is a simple test that shows whether cancer has spread to the lungs.

Ultrasound of kidneys, bladder, and prostate: Ultrasonography can be used to look for the effects of a urinary blockage on the kidneys. This is indicated by signs of swelling within the kidney (hydronephrosis). This study can also be used to assess the bladder for any sign of urinary obstruction due to prostate enlargement by looking at the thickness of the bladder wall and the amount of urine left inside the bladder after passing urine.

Cystoscopy: This is an endoscopic test which is usually performed in selected situations. A thin, flexible, lighted tube with a tiny camera on the end is inserted through the urethra to the bladder. The camera transmits images to a video monitor. This may show whether the cancer has spread to the urethra or bladder.

Technetium Tc 99m bone scan: This test is like an X-ray film of the entire body taken after a mildly radioactive substance is administered into a vein. The radioactive substance highlights areas where the cancer has affected the bones. This test is usually reserved for men with prostate cancer who have deep bone pain or a fracture or who have biopsy findings and high PSA values (>10-20 ng/ml) suggestive of advanced or aggressive disease.

Biopsy: When the findings of the physical exam, lab tests, and imaging studies suggest that a cancer is present in the prostate, the diagnosis must be confirmed by taking a sample of the tumor (biopsy). The tumor tissue is examined by a doctor who specializes in diagnosing diseases by looking at cells and tissues (a pathologist).

There are several different ways of obtaining a prostate biopsy.

The standard method uses transrectal ultrasonography to guide collection of the tissue sample. The sample is collected by inserting a needle into the tumor and withdrawing cells. Typically 10-12 pieces of tissue are extracted from different parts of the prostate gland to look for the presence of cancer.

A pathologist then examines the pieces under the microscope to assess the type of cancer present in the prostate and the extent of involvement of the prostate with the tumor. One can also get an idea about the areas of the prostate that are invaded with the tumor by assessing which of the pieces contain the cancer and which of them do not.

Another very important assessment that the pathologist makes from the specimen is the grade (Gleason's score) of the tumor. This indicates how different the cancer cells are from normal prostate tissue. Grade gives an indication of how fast a cancer is likely to grow and has very important implications on the treatment plan and the chances of cure after treatment. A Gleason score of 6 generally indicates low grade (less aggressive) disease while that of 8-10 suggests high grade (more aggressive) cancer. A grade of 7 is regarded as somewhere in between these two.

Staging: If the biopsy finding is positive for cancer, further staging procedures will be done.

Staging is a system of classifying tumors by size, location, and extent of spread, local and remote.

Staging is an important part of treatment planning because tumors respond best to different treatments at different stages.

Stage is also a good indicator of prognosis, or the chances of success after treatment.

Staging is usually accomplished through imaging studies and lab tests.

Prostate cancers are also assigned a grade, which indicates how different the cancer cells are from normal prostate tissue. Grade gives an indication of how fast a cancer is likely to grow.

The stages of prostate cancer are as follows:

Stage I (or A): The cancer cannot be felt on digital rectal exam, and there is no evidence that it has spread outside the prostate. These are often found incidentally during surgery for an enlarged prostate.

Stage II (or B): The tumor is larger than a stage I and can be felt on digital rectal exam. There is no evidence that the cancer has spread outside the prostate. These are usually found on biopsy when a man has an elevated PSA level.

Stage III (or C): The cancer has invaded other tissues neighboring the prostate.

Stage IV (or D): The cancer has spread to lymph nodes or to other organs.

Most doctors currently use the 2002 TNM (Tumor, Node, Metastases) staging system for prostate cancer. This is based on a combination of three criteria: the extent of the primary tumor (T stage), involvement of lymph nodes by the cancer (N stage), and the presence or absence of spread to distant areas of the body in the form of metastasis (M stage). The TNM 2002 staging system is as follows:

Evaluation of the (primary) tumor ("T")

TX: cannot evaluate the primary tumor

T0: no evidence of tumor

T1: tumor present but not detectable clinically or with imaging

T1a: The tumor was incidentally found in less than 5% of prostate tissue resected (for other reasons).

T1b: The tumor was incidentally found in greater than 5% of prostate tissue resected.

T1c: The tumor was found in a needle biopsy performed due to an elevated serum PSA.

T2: The tumor can be felt (palpated) on examination but has not spread outside the prostate

T2a: The tumor is in half or less than half of one of the prostate gland's two lobes.

T2b: The tumor is in more than half of one lobe but not both.

T2c: The tumor is in both lobes.

T3: The tumor has spread through the prostatic capsule (if it is only part-way through, it is still T2).

T3a: The tumor has spread through the capsule on one or both sides.

T3b: The tumor has invaded one or both seminal vesicles.

T4: The tumor has invaded other nearby structures.

It should be stressed that the designation "T2c" implies a tumor which is palpable in both lobes of the prostate. Tumors which are found to be bilateral on biopsy only but which are not palpable bilaterally should not be staged as T2c.

Evaluation of the regional lymph nodes ("N")