Despite potential risks and limited benefits, many Americans are still screened for cancers toward the end of their lives, according to a new study.
Up to half of older people in the U.S. received cancer screenings even though there was a high likelihood that they would die within nine years without cancer, researchers report in JAMA Internal Medicine.
“There is general agreement that routine cancer screening has little likelihood to result in a net benefit for individuals with limited life expectancy,” write Dr. Trevor Royce and his fellow researchers from the University of North Carolina, Chapel Hill.
Several professional societies have updated their cancer screening guidelines to suggest that people who aren’t expected to live another 10 years should not be screened for certain cancers.
For example, the American Society of Clinical Oncology, the American Cancer Society and the American Urological Association recommend stopping prostate-specific antigen (PSA) screening among men not expected to live another decade.
PSA screening involves a blood test that looks for a protein produced by the prostate gland. High levels of the protein may suggest the presence of prostate cancer.
"Each screening test carries different risks and benefits,” said Keith Bellizzi of the University of Connecticut‘s Center for Public Health and Health Policy in Storrs. "Individuals should be counseled about these risks in order to make an informed decision (sometimes involving caregivers or family members)."
Bellizzi was not involved with the new study but has done similar research (see Reuters Health story of December 12, 2011 here: reut.rs/1taT7L9).
“Having said that, the challenge for clinicians is to balance the values and wishes of their patients with the available evidence regarding the benefit or lack of benefit for a specific screening test,” he wrote in an email to Reuters Health.
For the new study, the researchers analyzed data from a U.S. survey collected between 2000 and 2010 that included responses from 27,404 people 65 years old and older.
They used the participants’ responses to estimate their risk of death within the next nine years. Then, they looked to see who had recently been screened for prostate, colon, breast and cervical cancers.
In one way or another, medical organizations support stopping screening for those four cancers among people with limited life expectancy.
Despite those guidelines, the researchers found 55 percent of men who had a 75 percent risk of death over the next nine years had recently received a PSA screening.
About a third of women with the same life expectancy received breast and cervical cancer screenings. Screening for cervical cancer was also common among women who had already had a hysterectomy.
The researchers also found that 41 percent of people who were not likely to live another decade were recently screened for colon cancer.
In an editorial accompanying the new study, Dr. Cary Gross of Yale University in New Haven, Connecticut, writes that some research found that older Americans receive colonoscopies within seven years of their previous screening. Current recommendations suggest 10 years between colonoscopies with normal results.
Another study published in the same journal says that based on a computer model, screening older adults with colonoscopies more than once every 10 years produced small benefits.
Researchers led by Frank van Hees of Erasmus University Medical Center in the Netherlands found that compared with screening older Americans with colonoscopies every 10 years, screening them every five years saved less than one additional life per 1,000 people.
Screening older Americans with colonoscopies every five years also resulted in less than one quality year of life gained per 1,000 people at a cost of about $711,000.
“This new age of skepticism is providing us with critical tools to better target screening efforts,” Gross wrote. “In situations in which we are uncertain about whether benefits outweigh the risks, we need to bolster our efforts to generate evidence that can inform cancer screening decisions.”
While helpful, he added, additional research is inefficient and doctors and regulators need to take steps to address the use of cancer screenings among people with limited life expectancies.
"These findings support other studies that suggest certain segments of the older population may be inappropriately screened for cancers," said Bellizzi. "However, the health care response should clearly not be a one size fits all solution."
He said older adults and their health statues differ from one another.
"Age, in and of itself, should not be a proxy for health status or be solely used as a decision tool regarding screening for a particular cancer," he added.