The one method to reduce the risk of deaths from advanced prostate cancer is to catch them early by effective method of screening. A recent study suggests that effective screening can prevent as much as 35% deaths.
Prostate cancer is the most frequently diagnosed cancer in men and is the second leading cause of death by cancer in men in the USA. Many of these cancers are discovered when they have already spread to other organs. PSA blood test is a simple tumour marker that rises early in prostate cancer. Most of the times it indicated an underlying disease before it is apparent clinically.
Vivek Goel, Professor of Public Health Sciences and Health Policy Management and one of the authors of the study said: "Early screening with the prostate specific antigen (PSA) is quite controversial. There are many arguments both for and against the efficacy of this form of early screening, our study shows a fairly significant benefit, and this benefit is demonstrated even among men who were not screened regularly as part of a screening program. There may be greater benefit from an organized screening program."
"Just by chance alone you're going to be picking up some of those prostate cancers, and those people wind up getting labeled as prostate cancer patients," states Goel. "They get treatments for it, surgery, radiation, chemotherapy, hormonal therapy - all of which have side effects - not to mention the anxiety and agony associated with having prostate cancer as a label. But the reality also is that they may never have actually died of the prostate cancer because it was so localized."
The study is published in the August issue of the Journal of Urology. When the data of the study was compiled the two researchers Kopec and Goel, were surprised by the size of the protective effect. "What usually happens with tests like these is that clinicians tend to be very supportive while public health people tend to be more cautious," says Kopec. "The clinical members of our study team feel that these findings are confirming what they had believed all along; we were a bit more surprised. A 35 per cent difference is quite a large amount so from our perspective it is quite a significant link in the chain supporting that early prostate screening has a positive impact."
Screening for prostate cancer has been controversial unlike that for cervical and breast cancer. Currently screening with PSA and Digital Rectal Examination annual checks are recommended in some parts of the world in men over 50 years. This study may make many health authorities give serious considerations to screening for prostate cancer.
This research was supported by a grant from the Canadian Cancer Society and a National Health Scholar Award from Health Canada.
Contact: Elaine Smith
University of Toronto