Maximizing Yield of the Fecal Immunochemical Test for Colorectal Cancer Screening

Colorectal cancer (CRC) is a leading cause of cancer death in the United States. Screening
for CRC reduces CRC mortality, yet rates of screening in the United States remain low. Fecal
occult blood testing (FOBT) has an established positive balance of benefit and risk, is the
least expensive, and is the preferred method for nearly half of patients. A newer fecal
screening test, the fecal immunochemical test (FIT), offers significant improvements over
the FOBT. It is easier to use and is more sensitive at detecting both CRC and precancerous
adenomas than the FOBT. The OC-Micro FIT is of particular interest because it is highly
sensitive and specific and it is the only FIT test approved in the US that can be processed
in an automated manner. Thus, the OC-Micro is an optimal method for use in mass screening
programs to improve community CRC-screening rates. However, prior studies of OC-Micro suffer
from several limitations: they were conducted in populations not optimal for assessing
screening performance in average risk patients in the U.S. and the studies did not clearly
establish optimal number of samples required and cut-points for test positivity. Therefore,
the overall goal of MY-FIT is to capitalize on the highly integrated and extensive
electronic medical record system of the study site to collect two separate sets of data
that, when synthesized, will provide a thorough picture of the comparative patient adherence
to, sensitivity, specificity, and costs of different protocols for using the OC-Micro FIT.
Specifically, among KPNW members aged 50-75 who are at average risk for colorectal cancer
(CRC) and who are due for CRC screening (n=78,000), the investigators propose to:

1. Compare the sensitivity, specificity, positive predictive value, and negative
predictive value for colorectal cancer and advanced adenoma (advanced neoplasia)
between a single-sample FIT (1-FIT) and a two-sample FIT (2-FIT) using varying cut
points for a positive test (n=2100).

2. Compare patient adherence to completion of a 1-FIT versus a 2-FIT protocol (n=3000).

3. Assess and compare cost per screen for a 1-FIT versus a 2-FIT protocol, and the cost
per advanced neoplasia detected in a 1-FIT versus a 2-FIT protocol (using varying cut
points for a positive test) (n=78,000).

Answering the above questions will provide a much-needed strong evidence base for a
best-practice, cost-effective method of using the OC-Micro FIT to screen for CRC in a
general U.S. population.