This month and next I would like to discuss the prostate gland. First, I will explore the symptoms and problems associated with the prostate, especially cancer. Then I will discuss methods of diagnosis and the different types of treatments.
The prostate is a walnut sized gland, located just below the bladder and is wrapped around the urethra. This placement is significant in that it explains why enlargement of the prostate often leads to difficult urination. The job of the prostate is to produce seminal fluid which nourishes and transports sperm.
The three main problems that affect the prostate are 1) infection, 2) enlargement and 3) cancer. Any of these conditions can produce symptoms like blood in the urine, pain or burning upon urination, difficulty in starting urination, frequent urination, flow of urine that starts and stops, sudden urgency to urinate, dribbling of urine, and constant pain in the lower back, thighs or pelvis.
The main area I want to address is cancer of the prostate.
The main methods of detecting prostate cancer are by a digital rectal examination (DRE) and by a blood test called the prostate specific antigen test (PSA).
Because of the proximity of the prostate gland to the rectum, a physician can place his finger in the rectum and palpate the gland, checking size and looking for hard lumpy areas, which may or may not indicate a problem. If the gland is smooth and just enlarged, a condition known as benign prostatic hypertrophy (BPH) is present. If any nodules or hard areas are found, further testing will be suggested to rule out cancer.
The disadvantage of the DRE test is that the doctor can only palpate part of the prostate, so some cancers will be missed. Also, if the cancer is small or is not hard, it also may be missed. It is a very subjective test; what one doctor considers hard, another may consider normal.Yet, like breast palpation it is considered a primary screening test.
The PSA is an interesting test. Prostate specific antigen is normally produced by the prostate and can increase for reasons other than cancer. It increases with infections, enlargement, inflammation, and from cancers other than prostate. If you had an ejaculation or a DRE within 48 hours of a PSA test, there may be a false elevation. The biggest problem with the PSA test is the number of false negatives. The test misses many of the cancers -82% in men under 60.
Dr. Thomas Stamey is considered the inventor of PSA testing and now feels that the PSA test leads to over-treatment. He has come to believe that the PSA test is not a useful predictor of the amount or severity of cancer; it is more indicative of the size of the prostate. He feels that all men develop prostate cancer if they live long enough. One out of every six men will be diagnosed with prostate cancer. By age eighty, 80% of men will have it. Thus there is a good chance that a biopsy will be positive for cancer. Dr. Stamey feels the PSA is still useful for those who have had their prostate removed, because cancer in other areas of the body will raise a PSA.Some also feel that the PSA has value when looked at over time. If the PSA number is steadily creeping upwards, they would be inclined to biopsy.
More on biopsies.
Most prostate biopsies are done by placing thin needles via the rectum into the prostate. These tiny needles may miss the cancer. If there is cancer, some doctors feel that the biopsy can cause a cancer to spread beyond the prostate. To me, this is a worrisome risk, because 46% of patients diagnosed with a prostate cancer that has breached the prostate capsule, die within 22 months; 70% die within five years.
As we see, PSA tests, DRE tests, and biopsies all have their shortcomings. Thus the question becomes, what is the best, least invasive, most reliable way to screen for prostate cancer? The procedure that makes the most sense to me is a sonogram test using a 3-D ultrasound with power color Doppler. The sonogram projects sound waves off the prostate and surrounding organs to give a 3-D image. There is no radiation or pain. A small probe is inserted into the rectum, and you can even watch the scan, as the results are projected onto a screen above your head.
Tumors grow at a faster rate than normal cells, and thus need more blood for nourishment. The color Doppler shows the blood flow patterns and thus will pick up increased areas of abnormal vascularization indicating a tumor. The severity of the problem is also indicated by the number of abnormal blood vessels.
Studies show that 3-D sonograms with power color Doppler to be over 90% accurate in detecting cancer. (This is also a great alternative to yearly mammograms). Using the three dimensional imaging, the prostate image is able to be rotated and the information stored digitally, so that comparisons can readily be made from one test to another. This technique gives visibility to the entire gland; thus areas that a biopsy may miss and that are not readily palpable are able to be more thoroughly evaluated.
If cancer is detected, or if cancer has been confirmed by a traditional biopsy, what to do next is the question. My next e-zine will discuss the various options.
© 2008, Mark A. Breiner, DDS
The information presented is for educational purposes only. You should consult a qualified health practitioner for diagnosis and treatment.