U.S. public may lack understanding of cancer screening

(Reuters Health) - Most people have inaccurate beliefs about what cancer screening tests can do and what they cannot, suggests a recent study from the U.S. National Cancer Institute.

Just 5.6 percent of survey respondents scored 100 percent on four true/false questions about the accuracy and value of cancer screening, the study authors report in American Journal of Preventive Medicine.

“That’s a little bit alarming,” said lead author Megan Roberts, a cancer prevention fellow at the NCI’s Division of Cancer Control and Population Sciences in Rockville, Maryland. “We just haven’t done a good job in educating the public about these nuances in cancer screening that are important to understand,” she said in a telephone interview.

Research suggests that people overestimate the benefits of cancer screening, Roberts and her team note. To better understand lay people’s perceptions of cancer screening tests, they looked at the NCI’s Health Information National Trends Survey of a nationally-representative sample of 3,677 adults in 2014.

Just over 70 percent of participants responded correctly (false) to the first question, “These tests can definitely tell that a person has cancer.” Almost 92 percent got the second question correct, “When a test finds something abnormal, more tests are needed to know if it is cancer” (true). Just over one-third responded correctly (false) to “When a test finds something abnormal, it is very likely to be cancer,” while only about 20 percent stated correctly (true) that “The harms of these tests and exams sometimes outweigh the benefits.”

Men, racial or ethnic minorities, less educated people and those with a higher level of fatalism about cancer were less likely to get the questions right.

But those who had worked with their physician to make decisions about colon cancer screening were more likely to respond accurately that more tests are needed after a screening test result is positive. They also were more likely to know that an abnormal screening test result was nonetheless “not very likely to be cancer.”

“Educators, researchers and clinicians should think about opportunities to improve the accuracy of people’s beliefs about cancer screening,” Roberts said. “Certainly we want people who should be getting screened to receive cancer screening, it could be really beneficial to their health, but we also want to make sure that patients understand what the screening process is so they can make informed decisions.”

SOURCE: American Journal of Preventive Medicine, online March 15, 2018.