STAGING
Staging means determining how far the cancer has progressed. Has it gone beyond the capsule? If so, does it involve the seminal vesicles, lymph nodes, or other nearby organs? Has it moved to other parts of the body?Types. Clinical staging is done before any procedure is begun. Pathological staging is done only on prostates that have been removed by surgery. The value of pathological staging is mainly to determine if the cancer is likely to have escaped, meaning that further treatment is necessary.
Accuracy. Staging is very difficult, and therefore often inaccurate. A Mayo Clinic study of men who had radical prostatectomies found that they had been understaged in as many as 59 percent of the cases. Semin Surg Oncology 1994 Jan-Feb;10 (1):60-72
About undergradingLocation. Approximately 40 percent of all cancers begin near the urethra. They are more likely to be organ-confined. Approximately 60 percent begin nearer the edges and spread along the surface of the organ. These are far more likely to escape the capsule. Escape usually occurs at the weaker points, such as places where blood vessels enter the prostate. Once the cancer is out, it is likely to spread along the nerves and the seminal vesicles.
Chart of stages, University of Michigan
T-N-M system (Tumor, Nodes, and Metastases), National Cancer Institute
The many elements of staging
TESTS
PAP
RT-PCR
Ploidy Analysis
Renal Scan
Magnetic Resonance Imaging (MRI)
Chest X-ray
Lymph-Node Sampling
Cystoscopy
Bone Scan
ProstaScint
Intravenous Pyelogram (IVP)
Urinalysis
Computerized axial tomography (cat scan, CT scan)
A page that discusses most of these testsPAP measures serum prostatic acid phosphatase. PSA testing has pretty much replaced it, and is now most often used to check for metastatic prostate cancer. If elevated, it may indicate the cancer has escaped.
About the PAP testThings that can raise PAP levels:BPH
prostatitis
a digital rectal examination (DRE)
hepatitis
pneumonia
Paget's Disease
a cholesterol-lowering drug called Atromid-S.RT-PCR, the Reverse Transcriptase-Polymerase Chain Reaction blood test, is a relatively new, extremely sensitive technique for detecting minute amounts of a nucleic acid that makes PSA.
About RT-PCR (go to Molecular staging)Ploidy Analysis is an examination the biopsy cores to assess the aggressiveness of the cancer. The tumorous material from the biopsy sample is examined to determine whether it appears to be normal (diploid), abnormal (aneuploid), or duplicated (polyploid). The latter two are likely to be aggressive.
Dr. Oppenheimer, a pathologist, wrote in a note to SeedPods readers:
The ploidy analysis itself is controversial since it may not add any information to what is gathered by an accurate Gleason grading with special attention being paid to nuclear features. It is my opinion that this procedure, although useful in a certain fraction of new diagnoses (probably less than 20 percent), is generally less useful than often advertised.A description of ploidy analysisMagnetic Resonance Imaging (MRI) can detect the unique magnetic properties of cancerous cells. The MRI alone is not very useful for assessing the prostate and surrounding tissue, but when it is used with an endorectal coil, much more information is available. The coil makes measurement of the size of the cancer more accurate and may reveal whether the cancer has escaped the prostate or entered the seminal vesicles. However, few hospitals are equipped with the coils, and it is expensive.
Because the MRI uses magnetism to map your body, you may not be able enter it safely if you have plates or other metal objects in your body or a pacemaker, cochlear implant, or an aneurysm clip in your brain. (The operator and/or physician in charge should ask you this long before the procedure.) You will probably be asked not to eat for six hours before the exam.
The procedure is not painful, but men with claustrophobia may not be able to remain motionless in the narrow tube. Warn the technicians ahead of time so that they can provide you with a tranquilizer—or take one yourself. The machine is very noisy, so bring earplugs in case they don't have cushioned earphones for you.) The first phase takes about 45 minutes, the second (with the endorectal coil) takes about ten.
Description of an MRI
Value of the endorectal MRI
Magnetic resonance imaging in radiotherapy treatment planning
A new, open type of MRI intended for those who have claustrophobia or who are extremely overweight is being used in some hospitals.
About the open MRI (framed site)Computerized axial tomography (cat scan, CT scan) is used to check for cancer in the lymph nodes. It may also be used in mapping the prostate before radiation.
Cat scansCystoscopy is used to check the urethra, bladder, prostate, and kidneys. A urologist uses a tube to look inside the bladder. The instrument may have a rigid tube or a flexible one. (Flexible is better.) It may or may not contain a tiny TV camera.
Cystoscopy, brief explanationA renal scan is an alternative method of imaging the urinary tract. You will be given an injection of a radioactive material and asked to lie still. The test will take between 20 and 60 minutes. Give the doctor a list of all the medicines you have taken in the past 48 hours. The only preparation is drinking fluids. (Also called a kidney scan or a renogram.)
About renal scansAn intravenous pyelogram (IVP), also called intravenous urogram (IVU), is a series of X-rays of the organs of the urinary tract. It is done primarily to determine if the cancer has extended to those organs.About the intravenous pyelogramUrinalysis only requires you to urinate in a cup. (For the most useful sample, do not start to catch the urine until after the first few seconds.) The lab will count the red and white blood cells present in the urine.
About urinalysisA bone scan (bone scintigraphy ) This is a series of images of the bones, taken after a radioactive substance has been injected into the bloodstream. The test may reveal areas of rapid growth, which may be a result of the cancer. It is a simple and painless test. Bone scans are almost always routinely negative in newly diagnosed prostate cancer patients with small tumors and PSA levels of less than 20 ng/ml. Journal of Urology 145:313-318, 1991
For this reason, some doctors see no point in performing an expensive test on patients who appear to have early-stage cancer and a PSA level of less than 10 ng/ml. A positive scan is not necessarily evidence of cancer. A radiologist must determine whether it reveals cancer, a fracture, arthritis, or Paget's disease.
The first part of the procedure is an injection, after which you will be free to leave for a few hours. The second part requires lying still on a bench-like surface for the better part of an hour.
A brief introduction to metastatic cancer
About bone scans and metastases
About Paget's diseaseChest X-rays may be taken to find out if the cancer has spread to the ribs or lungs. One may also be taken to assess any respiratory problems should you have to be anesthetized for a procedure.
Chest X-rayProstaScint is a test for the possible spread of the disease to the pelvic lymph nodes. It involves several CAT scans and monoclonal antibodies, a type of blood protein that can locate and bind to cancer cells. Accuracy appears to be very high. So is the cost.
About the ProstaScint monoclonal antibody scan
Some of the places where the ProstaScint test is performedLymph Node Sampling If a cat scan reveals that the nodes appear to be enlarged, the next step may be to sample them with a laparoscope or a needle biopsy.
Lymph node dissection
About laparoscopes
Return to Overview
STATISTICAL TABLES
The lack of reliable staging guides led Dr. Alan Partin of Johns Hopkins Medical School to compare hundreds of clinical stagings with the pathological stagings of the same organs. The Partin I tables, which predict the likelihood that the cancer has escaped, are based on the DRE, Gleason score, and PSA. (Another set, called the Partin II tables, are used when PSA rises, to determine whether the disease is local or metastatic.)
An introduction to the Partin tables
Partin tables: explanation and calculator The same text as a PDF file
Partin II tables
Partin's Predictions: What Do They Really Mean?
TABLES, OVERVIEW TOP OF THIS PAGE
FINDING ASSESSING DECIDING TREATING LIVING