Population screening for colorectal cancer means getting FIT: the past, present, and future of colorectal cancer screening using the fecal immunochemical test for hemoglobin (FIT)

Abstract

Fecal immunochemical tests for hemoglobin (FIT) are changing the manner in which colorectal cancer (CRC) is screened. Although these tests are being performed worldwide, why is this test different from its predecessors? What evidence supports its adoption? How can this evidence best be used? This review addresses these questions and provides an understanding of FIT theory and practices to expedite international efforts to implement the use of FIT in CRC screening.

Keywords: Colorectal cancer; Colorectal cancer screening; Fecal immunochemical test for hemoglobin; Population screening.

Fig. 1

Cartoon illustrating lateral flow immunochromatographic analysis principle of a fecal immunochemical test for hemoglobin.

Fig. 2

Variable positivity rates of well-trained, well-supervised, and well-monitored analysts based on their guaiac fecal occult blood test results.

Fig. 3

Flow chart from invitation to detection with numbers, percentages, and 95% confidence intervals between brackets. Adapted from van Rossum LG, et al. Gastroenterology 2008;135:82-90, with permission from Elsevier. gFOBT, guaiac-based fecal occult blood test; FIT, fecal immunochemical test for hemoglobin.

Fig. 4

Fecal hemoglobin concentrations in 1,000 consecutive ambulatory patients with increased risk of colorectal neoplasia or symptomatic. Adapted from Levi Z, et al. Ann Intern Med 2007;146:244-255, with permission from American College of Physicians. SD, standard deviation; CI, confidence interval.