Advances in Fecal Occult Blood Tests: The FIT Revolution

Abstract

There is a wide choice of fecal occult blood tests (FOBTs) for colorectal cancer screening. Goal: To highlight the issues applicable when choosing a FOBT, in particular which FOBT is best suited to the range of screening scenarios. Four scenarios characterize the constraints and expectations of screening programs: (1) limited colonoscopy resource with a need to constrain test positivity rate; (2) a priority for maximum colorectal neoplasia detection with little need to constrain colonoscopy workload; (3) an “adequate” endoscopy resource that allows balancing the benefits of detection with the burden of service provision; and (4) a need to maximize participation in screening. Guaiac-based FOBTs (gFOBTs) have significant deficiencies, and fecal immunochemical tests (FITs) for hemoglobin have emerged as better tests. gFOBTs are not sensitive to small bleeds, specificity can be affected by diet or drugs, participant acceptance can be low, laboratory quality control opportunities are limited, and they have a fixed hemoglobin concentration cutoff determining positivity. FITs are analytically more specific, capable of quantitation and hence provide flexibility to adjust cutoff concentration for positivity and the balance between sensitivity and specificity. FITs are clinically more sensitive for cancers and advanced adenomas, and because they are easier to use, acceptance rates are high. Conclusions: FOBT must be chosen carefully to meet the needs of the applicable screening scenario. Quantitative FIT can be adjusted to suit Scenarios 1, 2 and 3, and for each, they are the test of choice. FITs are superior to gFOBT for Scenario 4 and gFOBT is only suitable for Scenario 1.

Human Dna Quantification in the Stools of Patients With Colorectal Cancer

“…These noninvasive method may offer advantages over FOBT based screening strategies for the detection of both CRC and critical precursor lesions (11,28) . A problem among the exams did in the stools is the achievement of the samples, three samples of three different days had to be collected for G-FOBT, 1 day for I-FIT or for DNA tests.…”

Faecal haemoglobin concentration and personalised assessment of the risk of colorectal neoplasia

“…In addition to the wide beneficial modification to lifestyles that has ensued over recent years, screening is considered to be a major cause why both the incidence and mortality of CRC is now decreasing, at least in well developed countries (3). There are many possible approaches to CRC screening (2), but faecal immunochemical tests (FITs) for haemoglobin are currently considered the non-invasive investigation of choice and are recommended in guidelines promulgated in very many countries (4).…”

Pre-operative stool analysis for intestinal parasites and fecal occult blood in patients with acute appendicitis

“…FOBT is based on detection of Hg in feces using guaiac-based technique, and newer technology and highly sensitive fecal immunochemical tests have also proved effective in screening for most common colorectal cancer. [27] No previous study in the literature investigating combination of appendicitis and FOBT has been located by current study authors as yet. It was current study finding that 14.7% of patients had positive FOBT, 53.3% of whom had PA.…”