NEW YORK--The benefits of prostate cancer screening are greatest among men whose overall life expectancy is more than 10 years. In a talk at Lenox Hill Hospital, John A. Fracchia, MD, said that the increased incidence and mortality of prostate
NEW YORK--The benefits of prostate cancer screening are greatestamong men whose overall life expectancy is more than 10 years.In a talk at Lenox Hill Hospital, John A. Fracchia, MD, said thatthe increased incidence and mortality of prostate cancer overthe past half century underscore the importance of early detectionin successful treatment.
Dr. Fracchia, clinical associate professor of urology, CornellUniversity Medical Center and chief of urology at Lenox Hill,outlined what he termed a rational approach to the early detectionof prostate cancer. Even with its shortcomings, prostate-specificantigen (PSA) testing has revolutionized the field, but he cautionedthat guidelines for its use are essential.
He recommended that screening be made available to all men withlife expectancy and functional capacity of 10 years or more, tothose at high risk, and, lastly, to anyone outside these two groupswho requests it.
Annual digital rectal examination in combination with PSA testingis the most effective screening mode for men over age 40, Dr.Fracchia said. Transurethral ultrasound is recommended only inthe event of abnormal findings from either of these two tests.
Prostatic acid phosphatase (PAP) testing is no longer regardedas worth doing, he commented.
He noted that more widespread screening results in too many positivediagnoses of prostate cancer, which in turn leads to too muchtreatment and excessively high medical costs.
Nationwide, prostate screening alone costs a staggering $11.88billion annually. Men whose life expectancy for other reasonsis less than a decade are needlessly subjected to diagnostic andtreatment procedures that will not prolong their lives. "Mostprostate cancer patients die with, not from, prostate cancer,"Dr. Fracchia said.
Currently recognized risk factors for developing prostate cancerare age, heredity, black heritage, high levels of dietary fat,and ultraviolet radiation exposure. Dr. Fracchia singled out ageas the most important.
"Because male life expectancy in the United States has risenby 30 years in the last century, we can expect a higher incidenceof prostate cancer in the century to come, simply because menare living longer," he said.
Heredity plays a part: Men with a first-degree relative with thedisease have a risk two times higher than that of the generalpopulation; the risk is nearly as high when a second-degree relativehas had the disease, and eight to nine times higher when botha first- and second-degree relative have had prostate cancer,he said.
For reasons that are not yet clear, black men present with higherPSA levels and more advanced, more disseminated disease; consequently,they have significantly lower survival rates than do other populationsof men. Contributing factors may include less access to medicalcare and a tendency to be less vocal about physical complaints.
Another possibility is that the decreased rate of absorption ofultraviolet radiation due to higher levels of melanin in the skinresults in radiation damage to structures closer to the skin surface(such as the prostate) than to deeper internal organs, Dr. Fracchiaspeculated.
Geography may be an index of risk in several ways, Dr. Fracchiasaid. The lower incidence of prostate cancer in the Sunbelt suggestsultraviolet radiation exposure as a risk factor, whereas the higherincidence in Western Europe and the United States as comparedto Asia may be the result of dietary differences.
The high animal fat content of the Western diet may affect androgenlevels in the prostate, which may in turn promote some types oftumor formation, he said. Carcinogens in cooked meat, a stapleof the Western diet, are another possible factor. The Asian diet,which relies less on animal protein and more on vegetables, ishigher in alpha linoleic acid (found in vegetable oils), whichmay have a protective effect.
Dr. Fracchia mentioned other possible risk factors that are notviewed as significant in the development of prostate cancer: benignprostatic hyperplasia, cadmium exposure, smoking, sexual activity,viral infections (notably cytomegalovirus), and vasectomy.
He cautioned that recent studies suggesting a higher relativerisk among men who have had vasectomies have been viewed as flawed.He urged that vasectomy continue to be offered to men who wantit and that reversal not be undertaken as a preventive measure.Nor, he added, is there justification for more stringent screeningguidelines for men who have undergone vasectomies than for thegeneral population.