Men and women who worry about cancer are more likely to want to get screened for colon cancer, but feeling uncomfortable at the thought of cancer makes them less likely to actually go for the test, according to a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

"Many people are afraid of getting cancer, but fear doesn't have the same effect on everyone," said Charlotte Vrinten, a researcher at the Cancer Research U.K. Health Behaviour Research Centre at University College London. "For some people, cancer fear motivates them to get checked up; for others, it puts them off from finding out whether they have cancer."

Vrinten and colleagues hypothesized that the differences might be based on how people experience fear: Some fearful people tend to worry a lot about cancer, while others feel physically uncomfortable thinking about it. "In our study, instead of using a combined measure of cancer fear, as is often done, we distinguished these different aspects of fear to see whether they had different effects on people's decisions about cancer screening," Vrinten added.

Vrinten and colleagues found that the effect of cancer fear depended on the type of fear. Worriers were more likely to want to get screened for colon cancer, but those who felt uncomfortable were 12 percent less likely to attend screening. "Twelve percent may not seem like a lot," added Vrinten, "but given that tens of thousands of people are eligible for this type of screening, it means a big difference in the number of people actually attending. Our study showed that cancer fear is still very common; more than half of our participants said they felt uncomfortable when thinking about cancer, and about a quarter worried a lot about cancer.

"Public campaigns often focus on increasing public fear about cancer, for example, by emphasizing how common cancer is or how deadly some types of cancer are. This might put some people off, rather than motivate them to get screened," said Vrinten. "Public information about endoscopic screening for colon cancer should help people understand that it can actually prevent colon cancer, so having the test can mean they have one less cancer to worry about."

Vrinten and colleagues recruited nearly 8,000 participants aged 55 to 64 years from the U.K. Flexible Sigmoidoscopy trial into their psychological substudy on cancer fear. This was 60 percent of those asked to participate, and 91 percent of them (54 percent women) had complete data on all three cancer fear indicators used in the study. Overall, 59 percent of the respondents were more afraid of cancer than of other diseases, 53 percent felt uncomfortable thinking about cancer, and 25 percent worried a lot about cancer.

Of the 6,299 participants (82 percent) who responded that they would "probably" or "definitely" take up the offer of colorectal cancer screening, 1,995 were randomized to receive a screening invitation. Records from the clinics that performed the endoscopic screening tests showed that 71 percent attended their appointment.

The study was supported by Cancer Research U.K. Vrinten declares no conflicts of interest.