Most Americans aged 75 years and older continue to undergo routine screening for breast, cervical, colorectal, or prostate cancer even though recommendations advise against it, according to a report in the Dec. 12/26 issue of Archives of Internal Medicine.
Approximately half of these older adults report that their physicians recommended the cancer screening.
"These persistently elevated rates of screening raise the question of whether the decision to be screened is being made without fully knowing or discussing the risks and benefits," said Keith M. Bellizzi, Ph.D., of the department of human development and family studies, University of Connecticut, Storrs, and his associates.
According to current U.S. Preventive Services Task Force guidelines, routine screening for breast, colorectal, and prostate cancer are not advised once patients reach age 75 years, and routine screening for cervical cancer is not advised once patients reach age 65 years. "There is general agreement that screening decisions should be individualized" in this age group, based on each patient's functional status, comorbidities, life expectancy, and personal preferences.
Dr. Bellizzi and his colleagues examined real-world cancer screening practices using data from the National Health Interview Survey, an annual canvass of 30,000 households across the country that is used to monitor trends in illness. They combined data from the 2005 and 2008 surveys, resulting in a sample of 49,575 adults. A total of 1,697 of these subjects were aged 75-79 years and another 2,376 were 80 years and older.
Sixty-two percent of women aged 75-79 years and 50% of those aged 80 years and older reported that they had recently undergone mammography. Those proportions are nearly as high as the 74% rate seen in the target population for mammographic screening, women aged 50-74 years, the investigators said (Arch. Intern. Med. 2011;171:2031-7).
Similarly, 53% of women aged 75-79 years and 38% of those aged 80 years and older reported having been screened for cervical cancer.
The rate of colorectal cancer screening was actually highest (57%) in men and women aged 75-79 years, and lower (48%) in the younger age groups specified by the guidelines as the target population. The rate of colorectal cancer screening was almost as high among subjects aged 80 years and older (47%) as it was in the target population.
Similarly, the rate of PSA screening for prostate cancer was highest in the 75- to 79-year-old group (57%), followed by the oldest group (42%), and was lower in the target population of men aged 50-74 years (40%).
Patients also were asked whether their physicians had recommended cancer screening. Such a recommendation was the strongest predictor of obtaining the screening.
As many as 62% of women aged 75-79 years said that their physicians had advised them to get mammograms; 48% of that population reported that they were advised to be screened for cervical cancer. As many as 65% of older men and women said their physicians had recommended colonoscopy, including 54% of those aged 80 years and older. And as many as 62% of older men said their physicians had advised them to get PSA testing.
Age Not the Only Factor
It can be argued that at least some of the screening rates in this study were not too high. For example, 56% of U.S. women aged 75-79 years are expected to live 10 years or more, so cancer screening rates of about 60% might not be unreasonable in this age group, said Dr. Louise C. Walter.
Age alone may not be as important as clinical factors, such as functional status, in judging the appropriateness of cancer screening. Such screening may be appropriate in a healthy 80-year-old man but inappropriate in a frail 80-year-old man with serious comorbidities, she noted.
"While arguments persist about what is the ‘right’ rate of cancer screening in older persons, it seems clear that the rate of informed decision-making should approach 100%," Dr. Walter added.
Dr. Walter is in the division of geriatrics at the University of California, San Francisco. Her work is supported by the National Cancer Institute and the San Francisco VA Medical Center. She reported no financial conflicts of interest. These remarks were taken from her invited commentary accompanying Dr. Bellizzi’s report (Arch. Intern. Med. 2011;171:2037-8).
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