Cancer Trends Progress Report

Colorectal cancer tests: The percentage of adults aged 50 to 75 years who were up-to-date with colorectal cancer screening, by sex, race/ethnicity, income, education level, and contributing test type. Before 2016, up-to-date was defined as having FOBT every year, a sigmoidoscopy every 5 years in combination with FOBT every 3 years, or a colonoscopy every 10 years. Beginning in 2016, up-to-date is defined as FOBT or FIT every year, fecal DNA testing at least every 3 years, CT colonography every 5 years, flexible sigmoidoscopy alone every 5 years or every 10 years in combination with yearly FIT, or colonoscopy every 10 years.

Colonoscopy or sigmoidoscopy: The percentage of adults aged 50 to 75 years who reported that they had a colonoscopy within the past 10 years or a sigmoidoscopy within the past 5 or 10 (if combined with FIT as of 2016) years, by sex and race/ethnicity. Rates for colonoscopy and sigmoidoscopy (as direct visualization tests) have been combined into a single measure due to current infrequent use of flexible sigmoidoscopy as a colorectal cancer screening test in the U.S. (≤2% of tests).

CT Colonography: Starting in 2010, the percentage of adults aged 50 to 75 years who reported that they had a CT colonography within the past five years, by sex and race/ethnicity.

FOBT or FIT: The percentage of adults aged 50 to 75 years who reported that they had a fecal occult blood test (FOBT) or FIT within the past year, by sex and race/ethnicity. For the 2000 National Health Interview Survey (NHIS), respondents were asked about both home- and office-based FOBTs; starting in 2003, respondents were asked only about home-based FOBTs. Starting in 2015, NHIS respondents were asked about both FOBT and FIT.

Fecal DNA: Starting in 2018, the percentage of adults aged 50 to 75 years who reported that they had a fecal DNA test within the past 3 years, by sex and race/ethnicity.

Measurement challenges

We track colorectal cancer screening rates in U.S. adults using a large, national, in-person survey in which people are asked about their health behaviors and the medical care they receive (see Data Source, below). There are important limitations to this method that impact what information we can accurately collect and how confident we can be in the findings. Studies have found that certain types of healthcare survey questions can be difficult for people to clearly understand and answer, and it is easy for some questions to be misinterpreted.

In the case of colorectal cancer screening, it can be challenging to determine by self-report alone if an individual received a colonoscopy for the purposes of looking for asymptomatic, previously undetected cancer or precancers (i.e., for screening purposes), or to follow up on symptoms or suspicious findings from a prior test (i.e., for diagnostic purposes). From an individual’s point of view the tests appear similar to the patient experiencing them. Our measure therefore captures general receipt of a colonoscopy (yes/no) more accurately than its underlying purpose. People also may have trouble distinguishing between some of the types of colorectal cancer screening tests available (e.g., FIT versus fecal DNA, flexible sigmoidoscopy versus colonoscopy). Additionally, people may not always accurately recall the specific time they received a particular test. Finally, cancer screening is looking for cancer before a person has symptoms, when they are not known to have had that specific cancer type before. Looking for new or recurrent asymptomatic cancer in a person previously diagnosed and treated for that cancer type represents a different type of testing known as surveillance testing. As people do not always accurately recall what medical tests they have received, the purpose of that testing, or its exact timing, our measure captures any type of colorectal cancer screening received by an individual, and the population may include those with a prior diagnosis of colorectal cancer. Our measure is a reasonable approximation, although an overestimate, of the true U.S. colorectal cancer screening rate, i.e., the measure is not perfectly comparing the actual frequency of adults’ use of colorectal cancer screening tests to national recommendations.