Maintaining Your Health on Mackinac
Part II Prostate Health: Early Cancer Detection Is Important
By Yvan Silva, M.D.

There continues to be a strong public health policy regarding prostate cancer, including media attention, public health education, advertised screening programs, and much discussion about treatment options that are available. Tremendous advances have been made in the last two decades in prostate cancer research and treatment. The disease has been around for a long, long time and has always been tied to well-known risk factors as a disease of older men, increasing in incidence with aging.

The prostate is a walnutsized gland, located just below the urinary bladder, deep in the lower abdomen or pelvis. It surrounds the upper part of the urethra at the outlet of the urinary bladder. Its main function is to produce most of the fluid in the semen that nourishes and transports sperm. The urinary tract passes through it and it surrounds that part of the urethra called the prostatic urethra. The prostate is influenced by the male hormone testosterone, and it tends to enlarge as a man gets older.

The prostate gland is pea-size at birth, growing slowly through childhood, and undergoes a growth spurt at puberty. It is fully developed by age 25. In the mid-40s, growth increases in the central portion of the gland. The cells surrounding the urethra

grow more rapidly and compress the urethra, causing obstruction of urinary flow. This benign growth continues with age and affects 50 percent of men in their 60s and close to 80 percent of men in their 80s. Since it surrounds the urethra, this can begin to obstruct urinary flow, increasing the frequency and difficulty of urination. A rather common symptom doctors inquire about is nocturia, frequent urination that interrupts sleep. This common condition is benign prostatic hypertrophy (BPH), and it is not cancer. Medical and surgical treatments available to manage this problem are different from those required for prostate cancer. More than half of all men will experience some type of prostate problem in their later years. The three most common are prostatitis (inflammation of the prostrate), BPH, and cancer. Prostate cancer is most common after age 50, increasing in frequency with age.

Malignant tumors in the prostate develop in the outer portions of the gland and may grow at a varied pace. Prostate cancer is present in 25 million American men older than 50. Not all of them will have symptoms referable to the prostate, or die because of it. The statistics differ from many other common cancers in men. The lifetime risk of a man developing prostate cancer is 1 in 10, which is similar for breast cancer in women. Only about 25 percent who develop it will die from it and overall, only three percent of all men die from prostate cancer. It is the most common male cancer, and is dreaded by men in ways similar to breast cancer in women. While it seems that the occurrence of this cancer is rising sharply, it is more likely the use of the PSA test and other screening methods have uncovered cases that previously went undiagnosed.

Prostate cancer may not produce any symptoms in the early stages. When symptoms appear, they may be similar to those of BPH. About 40 percent of cases are diagnosed after the cancer has spread beyond the prostate itself. This highlights the need for screening and early detection. Symptoms and signs may include a sudden urge to urinate, pain during urination, difficulty starting to urinate, a weak stream and dribbling of urine, frequent urination during the night, painful ejaculation, and lower pelvic pain.

There are three investigations that are used to diagnosis this condition, initially. The digital rectal examination, in which the doctor palpates the gland rectally for size, consistency, and areas that may be suspect; the trans-rectal ultrasound, in which a probe is inserted into the rectum and an ultrasound records size, density, and abnormal areas, and lastly, the prostatespecific antigen test (PSA). These three constitute the screening process. To prove the diagnosis, if there are suspicious areas, a biopsy of one or more areas is done with a needle and examined under the microscope.

What is relatively new and now broadly applicable is a blood test that measures levels of a protein elaborated by the prostate gland, the Prostate Specific Antigen (PSA). The PSA has thoroughly modernized scientific knowledge about the prostate and made rapid and accurate diagnosis possible. The PSA is a very sensitive test in that the levels are very reliable in relating to the probability and extent of the cancerous process. It can be done routinely as any other blood test in the process of a physical checkup. Normal levels indicate the absence of cancer. Mildly elevated levels may not mean much, since benign enlargement of the prostate and urinary infections can raise levels. Very high levels are found when large tumors are present and when the spread of the cancer has occurred beyond the prostate. Even with mild elevations, when other indications exist, such as suspicious areas on physical and ultrasound examination of the prostate, a biopsy may be recommended to be sure that cancer is absent.

Several personal and ethical dilemmas emerge from these advances in diagnosing the disease. First of all, we are not all that sure how to treat it. While the PSA test can help detect cancer in the early stages, when all the information is put together it does not identify the men most likely to benefit from surgery. Unlike mammograms in women, that do help in saving lives, there are no available studies to define the best treatment for each man. There is a false positive rate in about 10 percent; that is, the level is high enough to suggest cancer when there is none. This group often must undergo the emotional and physical effects of further testing, the pain of biopsies, and anguish about the diagnosis. And about two percent of cases do not show an elevated PSA, when cancer is present.

The problem is that prostate cancer is very different at different ages. Some have it for years, with no symptoms or minimal symptoms, with no spread of the cancer. And in many autopsy studies 10 percent of men at age 50, up to 70 percent at age 80, have been found to have small cancers that had never spread and caused any problems. It is difficult to tell, then, when PSA testing or biopsy detects a cancer whether it falls into this category or if it is indeed an aggressive, life-threatening cancer. And therefore, it is even more difficult for patient and doctor to pick the right option, surgery followed by radiation or watchful waiting with appropriately timed follow-up testing. It is a fact that there has been a great increase in the number of surgically treated cases, coinciding with the increased availability of PSA testing.

What then is the reasonable approach for a man to undergo screening for prostate cancer with PSA testing? Men under age 50, with no prostate symptoms, need not be screened. If there is a family history of prostate cancer, men 50 years and older should be screened. Men older than 75 years may decide not to be screened, given the slow growth and spread of the disease. African-Americans have a higher risk, and screening should begin at 50, or starting at 40 if there is family history. Clearly, all men with suspect physical examinations and those with prostate symptoms should get a PSA test.

When prostate cancer is detected, there is no standard treatment method. Men younger than 60 are more likely to opt for surgery. Some men choose aggressive treatment when the diagnosis is made. It is important to choose a surgeon experienced in techniques that result in lower rates of impotence and urinary incontinence.

The options available are watchful waiting with close follow up, especially in older men in their seventh and eighth decades depending on other physical factors, and surgery, radiation, chemotherapy, and hormonal therapies, sometimes in combinations that can be difficult to choose from, at best. Second opinions and careful consideration on the part of the patient are well advised.

Several important studies are underway in many research centers, including the National Cancer Institute. The goals are to detect prostate cancer and, more importantly, find ways to differentiate those men who would be best treated by aggressive methods from those who might need lesser treatments, if any. Treatment methods are advancing. The potential for early detection in the early stages is very good. Regular physical examinations and screening as recommended remain the best ways to take advantage of current knowledge of this disease.

Dr. Silva is a professor of surgery at Wayne State University and a resident of Woodbluff on Mackinac Island.