"When if ever are people just too old to benefit from cancer httphealth.nytimes.comhealthguidesdiseasecanceroverview.htmlinlinenytclassifier screening The question keeps arising and has never been satisfactorily answered. Now it has come up again in the context of a provocative new study on the popular P.S.A. httphealth.nytimes.comhealthguidestestpsaoverview.htmlinlinenytclassifier test for prostate cancer httphealth.nytimes.comhealthguidesdiseaseprostatecanceroverview.htmlinlinenytclassifier. The paper httpjco.ascopubs.orgcontentearlyJCO....abstractsideccbdccbafbcaa published in The Journal of Clinical Oncology finds that men in their s are being screened at nearly twice the rate of men in their s  and men ages  to  are being screened as often as those  years younger. That is mindboggling said the lead author Dr. Scott E. Eggener a University of Chicago urologist. What we were hoping was that young healthy men who were most likely to benefit would be screened at higher rates and that screening would tail off in older men. The American Cancer Society and the American Urological Society discourage screening for men whose life expectancy is  years or less. The cancer is so slowgrowing that it can take that long for screening to show a benefit. The United States Preventive Services Task Force recently concluded that screening should stop at . Dr. Mary Barton scientific director for the group said it is more than just a lack of data that led to that conclusion. What data we do have for this group suggests it is a netharm situation she added. But although yearolds are much more likely than yearolds to have chronic illnesses and a limited life expectancy age should not be the deciding factor Dr. Eggener said. Health condition and life expectancy are far more important he said. There are yearolds that shouldnt be screened and yearolds that may benefit from it. The new study only included national data through  the most recent year they were available but said Dr. Durado Brooks director of prostate and colorectal cancers for the American Cancer Society http there is no reason to believe it has changed significantly since . Doctors said there are several reasons screening seems to continue indefinitely as men age. They range from patient demands to malpractice fears to financial incentives and doctors own lack of understanding of the risks and benefits of screening. There are a lot of pressures said Dr. Gerald L. Andriole a urologic surgeon at Washington University. It is not all pure data that is promoting aggressive screening. Dr. Andriole is directing a National Cancer Institute study http of  men that failed to find a screening benefit after  years. The men were aged  to  when the study began. P.S.A. screening is controversial at any age. Screening proponents say the cancer institute study was flawed and point to a European study http of  men aged  to  that showed a  percent drop in the prostate cancer death rate with screening. Screening critics say the European study was flawed and add that there is a logical reason it has been hard to show a screening benefit.  They note that prostate cancer is a common cancer found in most mens prostates on autopsy although often the men had no idea they had it. The cancer can be lethal but it usually grows so slowly that men die with it not because of it. For most men screening only has harms because it leads to biopsies and treatments with unpleasant side effects. And they say it might not help cure many deadly prostate cancers because those cancers may have already spread outside the prostate microscopically seeding other organs long before a P.S.A. test indicates a possible problem. A positive P.S.A. test usually leads to a biopsy httphealth.nytimes.comhealthguidestestbiopsyoverview.htmlinlinenytclassifier and then if cancer is found to a decision about whether to treat it. Nearly all men opt for treatment which includes surgery to remove the prostate or radiation to destroy the cancer. Side effects can include impotence httphealth.nytimes.comhealthguidessymptomserectionproblemsoverview.htmlinlinenytclassifier and incontinence. Even younger men should weigh the harms of screening says Dr. Lisa Schwartz of Dartmouth Medical School. You also have the potential to wreck their lives she said. One reason treatment is the most common choice is that it is hard to know if a cancer is lethal. Pathologists can distinguish between cancers that look particularly aggressive and those that do not but there is a real possibility that even if tissue obtained at a biopsy has only less aggressive tumor httphealth.nytimes.comhealthguidesdiseasetumoroverview.htmlinlinenytclassifier cells more aggressive cells might still be lurking in the prostate. But even with this uncertainty prostate cancer specialists say most men who are treated would not have died of prostate cancer and that is especially true for elderly men in particular those who are frail and have a limited life expectancy. Yet changing medical practice can be difficult.  Anytime a practice becomes ingrained it is difficult to eradicate says Dr. Brooks. It is harder to get rid of an aberrant behavior than to adopt a new one. Dr. Andriole said the very concept of not screening is difficult. It is the hardest thing in the world not to look for a cancer and not to treat it he says. And doctors he added have many inducements to screen. They often are afraid they could be sued if they do not screen and a man is found to have a lethal cancer. And there are financial incentives. Urologists make money by finding ways to biopsy men and administer treatments Dr. Andriole said. Screening he added is promoted by hospitals httptopics.nytimes.comtopnewshealthdiseasesconditionsandhealthtopicshospitalsindex.htmlinlinenytclassifier and industry. And he added many patients demand it.  Dr. Brooks of the cancer society says he travels the country and talks to primary care doctors about screening and has learned that many have misconceptions about the tests benefits. They often dont appreciate the downside of screening Dr. Brooks said and they dont appreciate the delay in benefit. In addition Dr. Brooks said primary care doctors often overestimate the likelihood that early detection of prostate cancer will lead to survival benefits. Added to that Dr. Brooks said is the length of time it takes to discuss the pros and cons of screening with patients. Often it is easier to just order the test. Dr. Bruce Roth a professor of medicine at Washington University in St. Louis said that ideally a doctor should take a mans overall health into account and not just go by age in ordering P.S.A. tests. But if a man has been screened year after year it can be hard to suggest he stop because he may not live much longer. Some men say the cautions just do not apply to them. J. Allen Wheeler who is  and lives in Portland Ore. said he had his most recent P.S.A. test in January. His doctor orders it routinely he says adding In all honestly its part of my physical. His doctor just does it  thats the understanding between us. Mr. Wheeler who says his health is fairly good said he could not foresee a time when he would stop having the test. He would like to know if he has cancer he says although he may decide not to be treated. A yearold Connecticut man said he had the test because he was healthy and wanted to stay that way. I think I am going to live to be  he said asking that his name be withheld to protect his privacy. A recent P.S.A. test found a small cancer and he does not want to take a chance that it will grow slowly and not cause him problems. I am thinking seriously of having the whole thing taken out he says. Hasta la vista. Correction April    An article on Tuesday about the risks and benefits of prostate cancer screening for men in their s and s misstated the academic affiliation of Dr. Bruce Roth who said doctors should consider a mans overall health and not just his age in deciding whether to order the test. He is a professor of medicine at Washington University in St. Louis not at the University of Washington."