Study Finds CT Colonography is Extremely Underutilized

Despite a lower rate of complications and being less invasive than optical colonoscopy, computed tomography colonography (CTC) is significantly underutilized for colorectal cancer (CRC) screening, according to a new study published in the Journal of the American College of Radiology.

The study involved 13,709 people, who had responded to the 2019 National Health Interview Survey. The study participants had no history of CRC and ranged between 50 to 75 years of age. According to the study, 67 percent of the respondents acknowledged having an optical colonoscopy or sigmoidoscopy in the past. This included 71.1 percent of White study participants, 66.8 percent of Black participants, 57.9 percent of Native American participants, 55 percent of Asian participants and 49.6 percent of Hispanic participants. However, only 1.4 percent of the total respondents acknowledged having a CTC procedure, according to the study.

While noting that a variety of factors likely contribute to the “persistently low use of CTC,” the researchers noted that other authors have pointed to the lack of insurance coverage for CTC by Medicare and many private insurance companies.

The researchers also found that Black and Hispanic participants were more likely than other races or ethnicities to report having a CT colonography procedure for CRC screening. Noting that only 49.6 percent of Hispanic participants reported having an optical colonoscopy or sigmoidoscopy in the past and that Black populations have the highest CRC incidence and mortality rates, the study authors emphasized that increased access to CTC could have a significant impact for at-risk populations.

“These (study) results suggest that expanding access to CTC may represent a valid and potentially more accepted method to increase CRC screening rates for racial and ethnic minorities and reduce CRC disparities,” wrote Anand K. Narayan, MD, the vice chair of equity in the Department of Radiology at the University of Wisconsin-Madison, and colleagues.

Out of those who had CTC, nearly 40 percent had the procedure within a year of the study while 11.2 percent recalled having the procedure in the last 10 years prior to the study and 9.6 percent had CTC more than 10 years prior to the study.

Dr. Narayan and colleagues noted that CTC can be performed locally with imaging assessment by a radiologist at another location, which could help reduce disparities in rural populations.

“CTC can help address some of the CRC screening disparities, especially if used in conjunction with screening modalities, by giving patients choice, increasing convenience, and improving access,” maintained Dr. Narayan and colleagues.

The study authors acknowledged limitations to the study, including self-reported adherence and the fact that the study was conducted prior to the United States Preventative Services Task Force recommendation to initiate routine CTC screening at the age of 45 instead of 50. They also did not ask about stool-based screening in the study. Pointing out that the study survey was conducted in 2019, Dr. Narayan and colleagues said the results do not reflect the impact of the COVID-19 pandemic on screening efforts for CRC screening.