Annual screening for prostate cancer does not reduce deaths, reveals study.
A longer follow-up of more than 76,000 men in a major U.S. study, led by Washington University School of Medicine in St. Louis, shows that six years of aggressive, annual screening for prostate cancer led to more diagnoses of tumours but not to fewer deaths from the disease.
"The data confirm that for most men, it is not necessary to be screened annually for prostate cancer," Newswise quoted Gerald Andriole, the study leader as saying.
"A large majority of the cancers we found are slow-growing tumours that are unlikely to be deadly," he said.
The PLCO study involved men aged 55 to 74, who were randomly assigned to receive either annual PSA tests for six years and digital rectal exams for four years or "routine care," meaning they had the screening tests only if their physicians recommended them.
The new research updates an earlier report of the data published in 2009 in the New England Journal of Medicine. At that time, when nearly all men had been followed for seven years, Andriole and his colleagues did not find a mortality benefit from prostate cancer screening.
Since so few men in the study had died from any causes, the researchers said then that it would be premature to make broad generalizations about whether men should continue to be screened. However, they did recommend against prostate cancer screening for men with a life expectancy of seven to 10 years or less.
"Now, based on our updated results with nearly all men followed for 10 years and more than half for 13 years, we are learning that only the youngest men - those with the longest life expectancy - are apt to benefit from screening. We need to modify our current practices and stop screening elderly men and those with a limited life expectancy," he said.
"Instead, we need to take a more targeted approach and selectively screen men who are young and healthy and particularly those at high risk for prostate cancer, including African-Americans and those with a family history of the disease," he added.
Andriole recommends that men get a baseline PSA test in their early 40s because recent studies have indicated that elevated levels at that age can predict the risk of prostate cancer in later years. Men in their 40s with low PSA levels are very unlikely to develop lethal prostate cancer and could potentially avoid additional testing.
The researchers detected 12 percent more prostate tumours among men screened annually compared to those who received routine.
However, deaths from prostate cancer did not differ significantly between the groups. There were 158 deaths from prostate cancer in the screening group and 145 deaths in the routine-care group.
Annual screening tests also did not reduce deaths from prostate cancer among men in their 50s and 60s, as the researchers had hoped.
The study has been published online in the Journal of the National Cancer Institute.