Knowing Cancer Risk May Not Increase Screening Adherence

Genetic cancer risk test results may not lead to healthier habits for patients with raised risk for colorectal cancer

(RxWiki News) Colorectal cancer (CRC) is a leading cause of cancer death in the US. And, despite knowing they face a raised risk for CRC, some patients aren’t following the doctor's orders to have routine cancer screenings.

In a recent study, researchers looked at whether telling patients how at risk they were for CRC — based on genetic test results — would motivate them to have routine CRC screenings.

The researchers found that patients who knew they had a high genetic risk for CRC weren't more likely to have routine cancer screenings than patients who had an average risk or who did not know their risk.

The Centers for Disease Control and Prevention (CDC) recommends that people beginning regular colorectal cancer screening when they reach the age of 50.

"Screening colonoscopies have the potential to remove precancerous colon polyps before they transform into cancer," said David Winter, MD, MSc, MACP, Chief Clinical Officer, President and Chairman of the Board of HealthTexas Provider Network (HTPN), a division of Baylor Health Care System. "Regardless of whether one has a test indicating a genetic risk or not, everyone should have routine screening per guidelines."

David S. Weinberg, MD, of Fox Chase Cancer Center in Philadelphia, and colleagues conducted this study. They studied 783 patients who had an average risk for CRC and had not been having regular cancer screenings. The patients were between 50 and 79 years old.

To determine whether knowing specific genetic risk for CRC improved patient screening habits, the study authors reviewed the patients' medical records and had them complete three surveys — one at the start of the study, one at three weeks and a final survey at six months.

The surveys questioned patients' adherence to cancer screening schedules. Patients were then randomly assigned to one of two groups: the genetic and environment risk assessment (GERA) for common diseases group and the usual care group. The patients in the usual care group did not know their individual risk for CRC.

GERA is predicted to become a leading CRC screening practice because it can identify an individual’s risk for disease, the study authors noted. It looks at genetic, chemical and environmental markers for diseases like CRC. The test was designed to influence patients who face raised risks for a disease to make medical decisions that could identify the disease early or possibly prevent it. In the case of patients with a raised risk for CRC, one such decision would be to have routine cancer screenings.

Routine cancer screenings can identify cancer early, which can raise patients' chances of surviving.

Based on their blood results, patients in the GERA group were advised that they had either a raised or average risk for CRC.

During the six-month study period, rates of cancer screening among the GERA group and usual care group were similar — 35.7 percent versus 33.1 percent, respectively.

More black patients had a raised CRC risk than white patients (71.6 percent versus 25.4 percent), the researchers found.

The authors found that 85 percent of the GERA patients had an average risk for CRC, a cancer that starts in the colon or rectum.

Education level appeared to be tied to whether patients who had a raised risk for CRC had routine cancer screenings. Patients with a college degree were 36 percent more likely than those with a high school diploma to have routine screenings.

Despite claims by media outlets that more knowledge about individual genetic risks promotes better health habits, the study authors said that knowing individual risk for CRC did not motivate patients to have routine cancer screenings.

This study was published Oct. 20 in Annals of Internal Medicine.

A grant from the National Institutes of Health funded the study. The authors disclosed no conflicts of interest.

Review Date: 
October 19, 2014