Tuesday, September 17, 2013
Free Prostate Screening! What's the catch?
The prostate is a walnut shaped gland that surrounds the urethra, in front of the rectum and just prior to the penis. It produces prostatic fluid which helps carry sperm to wherever they eventually end up. Prostate cancer screening, that is checking a man's prostate cancer via a rectal exam and also performing a blood test for PSA (Prostate Specific Antigen) has been of questionable utility for decades, and finally last year the US Preventive Services Task Force came out with their strongest statement ever, saying they recommended against prostate cancer screening. In prior recommendations they had questioned the utility of screening men at any age and had recommended that men over the age of 75 not be screened. Evidence piled up, however, showing that prostate cancer was significantly overdiagnosed, with many men being diagnosed and treated for prostate cancers which would never have caused them any harm if left undetected, and that the screening process itself, with biopsies and anxiety inducing repeated tests resulted in more harm than any help that would come of early detection. The members of the USPSTF, 16 nationally recognized MD and PhD volunteers who specialize in preventive medicine and public health, decided on this basis to recommend categorically against prostate cancer screening.
How is it possible that early diagnosis of cancer is bad? Cancer cells come and go in our bodies all the time. Some of them stay and produce tiny tumors that never cause us harm, others are eliminated by the immune system and by the normal processes of cell aging and death. Only some cancers become evil and endanger or kill us. If we detect the ones that would have caused us no harm, we then get treatment which is painful and harmful, expensive and dangerous. People die of over zealously treated cancers. Some particularly aggressive cancers, if detected early, will still kill us, but we will spend more of our lives having surgeries and chemotherapy than we would have if we had waited until they caused symptoms. Some cancers, of course, can be caught and eradicated at just the right time and finding these cancers can save our lives. Certain cancers are more likely to be cured when caught early than other ones. Colon cancer is frequently curable if caught early and fatal if allowed to spread. Some breast cancers are that way. Prostate cancer is extremely common as men age, and early autopsy studies concluded that if a man lived to be 100, he would have a nearly 100% chance of having prostate cancer if one were to check his prostate after he died of something else. A large proportion of men in their 70s and 80s have cancer cells and small tumors in their prostates, but have no symptoms and never will. People do die of prostate cancer, but detecting it early does not seem to make much difference in outcomes, at least not enough difference to outweigh the harms of screening. Prostate biopsy, which involves taking several needle cores of prostate tissue through the rectum, can cause persistent aching and blood in the urine, and sometimes detects cancer. Treatment of early prostate cancer involves removing the prostate via surgery or destroying it with radiation. Common side effects of these treatments include inability to control urination, diarrhea, sometimes bloody and uncontrollable, and inability to have an erection. These conditions don't actually kill a man, but they do significantly reduce his ability to vigorously engage in many important aspects of life.
This information is not a secret. For a time, the recommendation not to screen for prostate cancer was quite controversial. The American Urological Association, the professional organization of the doctors who biopsy prostates and operate on prostate cancers, did continue to recommend regular rectal exams and PSA testing until the last year or so, when they joined the American Cancer Society in recommending against screening before the age of 40 and after the age of 70, or for men with a life expectancy of less than 10-15 years. For the rest, they recommended screening only after discussing the risks and benefits of doing so with a doctor, with a shared decision making approach involving both science and the patient's preferences.
I thought perhaps this email I got was an artifact of an earlier age, and that this hospital had somehow failed to hear the news that screening all comers age 35 and above is a bad idea. Then I opened my local paper and found that one of our local hospitals was sponsoring a free prostate screening day with our local urologist. I googled Free Prosate Screening and came up with over 12 million results, some of which were recommendations against screening, but most were advertisements for free screenings, rectal exams and PSA testing.
Perhaps the urologists are not just doing a rectal exam and a blood test, but are dutifully discussing the risks and benefits of screening and engaging in shared decision making. But I doubt it. This subject takes a long time to discuss and shared decision making requires that the doctor explore the patient's expectations and values. Free screening clinics usually have lots of people and essentially no time for discussion. Perhaps symptom free 80 year olds would be turned away, but I can't really picture that. Instead I picture a waiting room full of apprehensive guys, many without access to a doctor willing to discuss preventive care with them, being hurried through a brief encounter with a doctor, a quick blood draw and then being handed a few possibly informative booklets which they will most likely never read.
Evaluating for prostate cancer is not a terrible idea if a patient has symptoms that might go along with prostate cancer, things like fatigue and bone pain and sometimes difficulty urinating or blood in the urine. This is not considered screening. This is a well thought out exam to help diagnose a disturbing symptom.
But what if a man just wants to know if he has prostate cancer, and then discuss the options of treating it or watching it with his doctor? Wouldn't PSA and rectal exam tests be useful for that? Such a can of worms. It is difficult for many men to be comfortable knowing that they have a cancer and not do anything about it. I have had patients who were at peace with this approach, but they were few. In America it is dramatic and somewhat embarrassing to admit to having cancer, but keeping it a secret is difficult too, especially from well meaning family. Also, having a normal PSA and rectal exam does not mean that a man is free of prostate cancer. Using a cutoff of a PSA of 4, about 15% of men screened with these tests had prostate cancer when biopsies were performed, in a study published in 2004. It is likely more cases would have been found had they used more modern biopsy techniques which sample 8-12 sites rather than the 6 samples taken by old protocols. "Normal" levels of PSA were adjusted down after this, labeling more healthy patients as abnormal.
So, bottom line, free prostate cancer screening is not free. PSA testing and rectal exams are not good ways to detect prostate cancers that would cause harm and could be cured by early treatment. Followup PSA testing may or may not help to detect more aggressive cancers but may not be paid for by insurance since PSA testing is deemed not to be very accurate. Prostate cancer is a bad disease, in many cases, and we need to continue to look for ways to detect the cancers that can be cured and effectively treat the ones that cause symptoms. But this does not involve foisting outdated screening routines on an unsuspecting public.