Colorectal cancer (CRC) is the third most common cancer and the third leading cause of cancer death in both men and women in the U.S., with nearly 50,000 deaths each year. Since CRC develops over a number of years from precursor lesions called polyps, it is largely detectable and preventable in early stages. As these polyps become larger, they, like most CRCs, tend to bleed, which is the rationale for the use of fecal occult blood tests (FOBTs) to detect both polyps and cancers early, while they are curable. However, early screening and detection is much less common than it could be, with about 43% of eligible individuals unscreened. Fecal immunochemical tests (FITs) are a type of FOBT that can be a sensitive, specific, and low- cost alternative to colonoscopy for CRC screening. Modeling studies have shown that for population screening, a strategy of annual FIT testing from age of 50 to 75 years results in an equal number of life-years gained as compared with colonoscopy every 10 years. However, about 90% of screening in the U.S. is done with colonoscopy, the most expensive and invasive screening test. FITs are far less costly and largely replacing the guaiac test in CRC screening programs internationally, where only individuals with positive results are referred for a colonoscopy. Studies done on FITs in other countries often used FITs not available in the U.S. or studied high-risk populations; thus, results are not applicable in the U.S. It is critical to determine the FIT(s) with the best test characteristics in order to implement successful FIT-based screening programs in this country. It is estimated that 24 million more individuals will need to be screened by 2018 to reach the ?80% by 2018? goal set by the National Colorectal Cancer Roundtable. To address this knowledge gap, we propose to compare the test characteristics of three CLIA-waived FITs and two automated FITs, using colonoscopy as the gold standard. The rationale for this proposed study is that, for almost all of the FITs currently marketed in the U.S., there is no evidence of the accuracy claimed.
Our aims are:
Aim 1 : To assess the diagnostic accuracy for advanced colorectal neoplasms of three of the most commonly used CLIA-waived FITs and two automated FITs, using colonoscopy as the gold standard.
Aim 2 : To evaluate the diagnostic accuracy of two quantitative FITs using receiver operating characteristic (ROC) analysis.
Aim 3 : To assess factors associated with false positive and false negative FIT results for each device. These findings will provide essential information about FITs with the best test characteristics for future expanded use of FIT, critically important to achieving our long-term goal of reducing morbidity and mortality from CRC. FITs are more acceptable to patients, will allow higher screening rates, and will reduce costs as compared with a screening strategy based on colonoscopy as the primary initial screening method.

Public Health Relevance

Colorectal cancer is a preventable and/or a treatable cancer, but 43% of the United States population is not up- to-date with screening. Although 90% of colorectal cancer screening is done using colonoscopy, most other countries use fecal immunochemical tests, reserving colonoscopy for those with a positive fecal immunochemical test. This project will provide the foundation for a paradigm shift for colorectal cancer screening in the United States by identifying how well 5 different FITs work for detecting screening relevant neoplasia, thus reducing morbidity and mortality for colorectal cancer.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA215034-03
Application #
9733992
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Young, Matthew R
Project Start
2017-08-01
Project End
2022-07-31
Budget Start
2019-08-01
Budget End
2020-07-31
Support Year
3
Fiscal Year
2019
Total Cost
Indirect Cost
Name
University of Iowa
Department
Family Medicine
Type
Schools of Medicine
DUNS #
062761671
City
Iowa City
State
IA
Country
United States
Zip Code
52242