CHICAGO – Two studies published Tuesday in the Journal of the American Medical Association (JAMA) revealed that fewer men are attending screening for prostate cancer in the U.S., which has led to a decline in early-stage detection. According to the American Cancer Society, an estimated of 220,800 men will be diagnosed with the disease in 2015, whereas about 27,540 of them will die of it.
In one study, researchers found that rates of the prostate specific antigen blood test (PSA) declined from 40.6% in 2008 to 30.8% in 2013. The other study revealed a reduction from 36% in 2010 to 31% in 2013. As a consequence, a significant drop in the incidence of prostate cancer was registered, since the less doctors screen, the less they find cancer.
In 2012, the United States Preventive Services Task Force, which is an independent panel of experts chosen by the government, discovered that risks of routine blood tests for PSA outweighed its benefits. This, however, is a matter of debate among experts in the medical field, since it has not yet been proven the precise time when screening and prevention treatments are more likely to be worth doing.
There are two currents of opinion on this issue, clearly explained by Dr. Quoc-Dien Trinh, an urologist at Brigham and Women’s Hospital and assistant professor of surgery at Harvard Medical School, as well as an author of one of the studies. “On one side of the fence, prostate cancer is over diagnosed, and you need to treat a lot of men to save one life. But there is also no doubt that if you stop PSA screening, what kinds of prostate cancer are you going to find? Most likely late stage cancers that have metastasized to the bone and are causing pain and bone fractures”, concludes Trinh.
Even though most early-stage prostate tumors detected through PSA happen to be meaningless and therefore do not require treatment, by refraining from screening doctors miss the chance to detect actual lethal cancers and early effective treatments could arrive too late to save a man’s life, according to Ahmedin Jemal, vice president of surveillance and Health Services Research at ACS and a co-author of one of the studies just published in the JAMA.
In contrast, Dr. Otis Brawley, chief medical and scientific officer for the American Cancer Society (ACS), affirmed that PSA screening leads to over diagnosis. She reported that 1.1 million men in the U.S. were treated over the past 20 years, even when none of those cases required any treatment.
All those differing opinions create confusion among patients and doctors who need to make an immediate decision. Dr. David Penson, chair of urology at Vanderbilt University, explained in an editorial accompanying the JAMA studies that PSA testing may be worthy but in certain men and should not be underwent yearly. He added that PSA should be combined with other new methods to detect prostate cancer, which will give doctors a more precise sense to distinguish patients who are really at risk of growing aggressive tumors from those less vulnerable.