"There is growing recognition among medical professionals that cancer screening is a double-edged sword," the authors write in background information to the study. "While some individuals may benefit from early detection, others may only be diagnosed and treated for cancer unnecessarily. ... the public needs access to balanced information about its [cancer screening] potential benefits and harms."
Lisa M. Schwartz, M.D., M.S., from the VA Outcomes Group, White River Junction, Vt., and colleagues conducted a national telephone survey of 500 adults during 2001 and 2002 to learn about adults' experience with a broad range of screening tests. The survey included 360 women aged 40 years or older and 140 men aged 50 years or older without a history of cancer. The survey included questions about the value of early detection; and four cancer screening tests: Papanicolaou (Pap) test; mammography; prostate-specific antigen (PSA) test; and sigmoidoscopy or colonoscopy.
"Most adults (87 percent) living in the United States believe routine cancer screening is 'almost always a good idea,'" the authors found. "Seventy-four percent believe that finding cancer early saves lives 'most' or 'all of the time'. Fifty-three percent believe screening usually reduces the amount of treatment needed when cancer is found."
"Less than one third believe there will be a time when they will stop undergoing routine screening," the authors report. "A substantial proportion believe that an 80-year-old who chose not to be tested was irresponsible: ranging from 41 percent with regard to mammography to 32 percent for colonoscopy. Thirty-eight percent of respondents had experienced at least one false-positive screening test; more than 40 percent of these individuals characterized that experience as 'very scary' or the 'scariest time of my life.'" But, the researchers write that 98 percent of those respondents were glad they had the initial screening test. Most of the respondents had a strong desire to know about the presence of a cancer, regardless of its implications: two-thirds said they would want to be tested for a cancer even if nothing could be done; and 56 percent would want to be tested for pseudodisease, which are cancers growing so slowly that they would never cause problems during the persons lifetime even if untreated. And the researchers report there is great interest in the total body computed tomographic (CT) screening, even though there are no data to support its benefit or safety, and it is not endorsed by any professional medical organization. Almost 75 percent of the respondents would choose a total body CT scan over receiving $1,000 in cash.
"Some clinicians will see our results as welcome evidence of the success of public health campaigns for widely recommended cancer screening tests," the authors write. "Others will have quite a different take. They will see disturbing evidence that these same campaigns have communicated a misleadingly simple and one-sided message - a message that discourages meaningful discussions about the use of these tests in settings when the recommendations are less clear (e.g., screening at younger ages, at advanced age, or for individuals with multiple comorbidities [illnesses]." The authors suggest that the public is primed to believe that there is value in having any test that is marketed as being able to find early cancer. In conclusion the authors write, "The challenge now is to balance messages and reduce the public's risk for overtesting and overtreatment."
The authors note that their findings are limited because they do not know whether the public's enthusiasm for early detection would change if the potential benefits and harms of screening were fully communicated and understood.
(JAMA. 2004; 291:71-78. Available post-embargo at JAMA.com)
Editor's Note: Drs. Woloshin and Schwartz are supported by Veterans Affairs Career Development Awards in Health Services Research and Development and by Robert Wood Johnson Generalist Faculty Scholar Awards. This study was supported by a grant from the Department of Defense Breast Cancer Research Program and a grant from the National Cancer Institute.