New research about why people forego colorectal cancer screening suggests that three fears play a significant role. Fear of embarrassment, fear of getting AIDS, and fear of pain may make some seniors skip the potentially lifesaving tests.

The strongest predictor of unwillingness to participate in screening was fear of embarrassment during a screening. Fear of getting AIDS, which prior studies have suggested revolve around the insertion of medical devices into the rectum, was the second strongest. Fear of pain also was associated with a reluctance to participate in screening.

"We found that people who feared that they might get AIDS, feared feeling embarrassed during the screening exam, those who were older, and those with only a high school education were more unwilling to get screened," says lead author Shalanda Bynum, an assistant professor of social and behavioral sciences at the F. Edward Hebert School of Medicine at the Uniformed Services University of the Health Sciences, in Bethesda, Md.

While earlier research has shown that barriers to CRC screening include factors such as income and race/ethnicity, this study, published in the American Journal of Health Promotion, sought to explore not only those factors but also psychosocial ones. It also sought to address the influence of a person's mistrust of medical providers and misconceptions, such as the notion that CRC screening might cause AIDS.

The AIDS issue warrants further investigation, said Jason Q. Purnell, an assistant professor at the George Warren Brown School of Social Work at Washington University. It also testifies to the need for public health efforts around CRC screening to increase patients' knowledge and address their fears, Bynum says.

The findings were based on telephone survey data from 454 individuals 50 and older living in New York, Baltimore, and San Juan. Study participants self-identified as African American, Hispanic, or white. They were asked how willing they were to participate in colon cancer screening and how much various fears or feelings, such as fear of finding out you have cancer or mistrust of doctors, would influence their decision.

One finding that the researchers and Purnell found surprising and consider worthy of closer study was that those who reported medical mistrust were less likely than others to indicate that they wouldn't get screened for CRC.

Purnell says, "Medical mistrust may heighten a person's sense of vigilance, making them more likely to undergo screenings in an attempt to guard against what they perceive as potentially inadequate care. The relationships of mistrust to colorectal cancer screening may be more complex than we originally thought."

People who generally feared developing cancers were also less likely to demonstrate avoidance of screening.

Although colorectal cancer rates have declined greatly in the past 20 years, it remains the second leading cause of cancer death in the US. Despite screening's proven ability to prevent CRC, 38 percent of adults over 50 have never had a sigmoidoscopy/colonoscopy and 79 percent have never had a fecal occult blood test.

The Uniformed Services University of the Health Sciences is a health science university run by the U.S. government. Its primary mission is to prepare graduates for service to the U.S. at home and abroad in the medical corps.