Frequently screening for prostate cancer may not reduce deaths from the disease, a new study says.
In the study, which involved about 76,000 men, those who underwent yearly screening for prostate cancer were just as likely to die from the disease over a 13-year period as those who underwent screening only if their doctor recommended it.
The findings suggest yearly screening for prostate cancer is not necessary for most men, the researchers said. Many of the cancers found were slow-growing cancers that would not go on to kill the patient, said study researcher Dr. Gerald Andriole, chief of the division of urologic surgery at Washington University School of Medicine in St. Louis.
That's not to say there's no benefit from screening, Andriole said. But screening should be focused on younger, healthy men and those at risk for the disease, such as those with a family history of prostate cancer.
"We need to modify our current practices and stop screening elderly men and those with a limited life expectancy," Andriole said.
The findings come a few months after the controversial decision by the U.S. Preventative Services Task Force to recommend against routine screening for prostate cancer in healthy men using the prostate-specific antigen test (PSA).
Dr. Bruce Kava, an associate professor of urology at the University of Miami Miller School of Medicine, who was not involved in the new study, said that men, old and young, should speak with their doctors about whether they are candidates for screening.
"We shouldn’t be predetermining for patients" whether they should get screened, Kava said.
Prostate cancer screening
The study involved men in the United States between ages 55 and 74. Participants were randomly assigned to undergo yearly screening — six years of screening with a PSA test and four years with a digital rectal exam — or to receive standard care, which meant being screened only if their doctor recommended it.
The researchers reported early results of their study in 2009, when participants had been followed for seven to 10 years. At that time, the data showed that screening did not reduce prostate cancer deaths. However, some argued the follow-up period was not long enough, given that prostate cancer can take many years to be lethal.
In the new study, men were followed for at least 10 years, and more than half were followed for 13 years.
About 12 percent more cases of prostate cancer were detected in the group that received yearly screening than in the group that received standard care (4,250 cancers in the screening group and 3,815 cancers in the standard care group).
However, the number of deaths from prostate cancer were about the same in both groups: 158 deaths in the screening group and 145 deaths in the standard care group.
In addition, men who were diagnosed with prostate cancer and had a history of other conditions — such as heart attacks, strokes and diabetes — were much more likely to die of something other than prostate cancer, suggesting that screening finds cancers that aren't likely to be the reason a man dies, the researchers said.
A critical flaw in the study is that the doctors of about half of the participants in the standard care group recommended they be screened for prostate cancer, meaning the researchers cannot definitely say that screening for prostate cancer is not beneficial, Kava said.
In addition, men with prostate cancer typically live for 15 to 20 years after their diagnoses, and so the follow-up period should be longer still, Kava said.
Before men undergo screening for prostate cancer, they should be fully informed about its pros and cons, said study research Philip Prorok, of the National Cancer Institute. Possible harms of prostate cancer screening include unnecessary biopsies and subsequent treatments, which come with a risk of erectile dysfunction and loss of urinary control.
An approach known as active surveillance is intended to reduce harms from prostate cancer screening. With active surveillance, men diagnosed with low-risk prostate are be closely monitored, and treated only if their cancer progresses to a more aggressive form.
A panel convened by the National Institutes of Health recently recommended more men undergo active surveillance rather than treatment.
Pass it on: Prostate cancer screening may not be necessary for older men, but patients should speak with their doctors about whether they are candidates for screening.