Clinicians more often use a strict age cutoff for stopping colon cancer screening than they do for stopping breast and prostate cancer screening, new data suggest.
Whether to continue screening and how to make that decision are “not necessarily consistent between clinicians or…cancer types,” study author Justine P. Enns, a researcher at Johns Hopkins University, Baltimore, Maryland, said at the American Geriatrics Society (AGS) 2021 Annual Scientific Meeting.
“Interventions to reduce overscreening need to acknowledge that clinicians do not think about cancer screenings homogeneously, and more…guidance is warranted to help clinicians make these complex decisions more systematically,” she said.
For older patients, the benefits of cancer screening are less clear, and the harms of screening may be greater than they are in younger patients. “Most professional societies do not recommend routine screening for breast, colon, or prostate cancers for older adults who have less than 10 years’ life expectancy,” Enns explained. “Despite this, clinicians are still regularly screening adults who meet guideline criteria for discontinuing these cancer screenings.”
To compare clinicians’ perspectives on discontinuing breast, colon, and prostate cancer screenings for older adults who have limited life expectancy, Enns and colleagues interviewed 30 primary care clinicians and identified major themes in their decision making process.
Stricter Threshold for Colon Cancer
The participants practiced in internal medicine, family medicine, internal medicine/pediatrics, and geriatrics. Their average age was 48.2 years, 53% were women, 80% were physicians, and 20% were advanced practice clinicians.
Clinicians more often screened beyond guideline-recommended ages for breast and prostate cancers than they did for colorectal cancer. With breast cancer screening, clinicians saw less of an association between older age and screening harms, and they tended to recommend mammograms for persons of older age, Enns said.
One clinician said that they will “do [mammograms] at any age because the risks are so minimal.” Another said, “I guess I have a tighter [age threshold] for colonoscopy…. Generally I don’t think of it for anyone after the age of 70.”
Clinicians also perceived more specialist involvement in colonoscopy screening decisions compared with decisions regarding prostate and breast cancer screening.
“More specifically, gastroenterologists could disagree with the primary care clinician’s referral, and therefore clinicians would try to proactively think about whether [a gastroenterologist] would even do a colonoscopy” for a particular patient, Enns said.
In making their decisions, clinicians weighed various harms and benefits. Key considerations included the efficacy of the screening test, the direct harms of the screening test, downstream harms of screening, the harm of unscreened advanced cancer, and the ease of cancer treatment. The most important factor could differ for each screening type.
One clinician described breast cancer as “the easiest to treat” and regarded that as a reason for continuing screening.
Clinicians were more aware of harms associated with prostate and colon cancer screenings and more readily discussed these harms with their patients.
For breast cancer screening, clinicians more often framed discussions with patients around a potential lack of benefit.
Bigger Care Priorities?
During a virtual question-and-answer session, Louise C. Walter, MD, professor of medicine and chief of the Division of Geriatrics at the University of California, San Francisco, wondered how overdiagnosis factored into the clinicians’ thinking.
“I think this is one of the major harms across cancer screening tests,” Walter said. “And time spent doing tests is less time spent on doing something else that might be more helpful.”
“Overdiagnosis definitely came up, particularly in conversations regarding prostate cancer screening,” Enns said.
Many interviewees noted that time in clinic is limited and that other elements of care, such as “medication deprescribing, fall risk reduction, and social aspects, could take the place of time normally spent discussing or pursuing screening,” Enns added.
Study coauthor Nancy Schoenborn, MD, MHS, associate professor of medicine and oncology at the Johns Hopkins University School of Medicine, addressed other reasons doctors may continue screening older patients.
“Although many recognize the diminishing benefit and increasing harms with increasing age and comorbidities, many also feel patients expect to be screened, worry about malpractice, quality metrics, etc,” she said during another session at the AGS meeting. “Many are also doing it out of routine or based on EHR prompts and not always having the time to weigh the benefits and harms deliberately. It takes active thinking to decide to not screen. Many clinicians are also not sure if the life expectancy prediction tools are accurate enough for them to use.”
A separate analysis by Schoenborn and coauthors, which was published online in JAMA Network Open and was presented at the meeting, showed that breast or prostate cancer screenings were associated with lower hazard of all-cause mortality after taking into account age, comorbidities, and functional status. The results indicate that prediction algorithms may be missing important variables associated with cancer screening and mortality, Schoenborn said. Missing variables could include nontraditional factors such as motivation, adherence, or resilience, the researchers suggest.
The finding reinforces the importance of eliciting and incorporating patients’ perspectives into screening decisions, Schoenborn said.
The studies were supported by the National Institute on Aging. Enns, Walter, and Schoenborn have disclosed no relevant financial relationships.
American Geriatrics Society (AGS) 2021 Annual Scientific Meeting: Abstracts B104 and P16. Presented May 13–14, 2021.
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