Advances in Fecal Occult Blood Tests: the FIT revolution

Area of Science:

• Gastroenterology
• Oncology
• Screening Technologies

Background:

• Colorectal cancer screening relies on various fecal occult blood tests (FOBTs).
• Guaiac-based FOBTs (gFOBTs) have limitations including low sensitivity, dietary interference, and fixed cutoffs.
• Fecal immunochemical tests (FITs) offer improved analytical specificity and quantitation capabilities.

Purpose of the Study:

• To evaluate FOBTs for colorectal cancer screening across diverse scenarios.
• To determine the optimal FOBT for different screening program constraints and objectives.

Main Methods:

• Comparative analysis of guaiac-based FOBTs (gFOBTs) and fecal immunochemical tests (FITs).
• Evaluation of test performance within four defined screening scenarios: resource limitation, maximum detection, balanced approach, and maximum participation.
• Assessment of sensitivity, specificity, and participant acceptance.

Main Results:

• FITs demonstrate higher clinical sensitivity for colorectal cancers and advanced adenomas compared to gFOBTs.
• FITs offer flexibility in adjusting positivity cutoffs, balancing sensitivity and specificity.
• gFOBTs exhibit deficiencies in sensitivity and specificity, with limited quality control and lower participant acceptance.

Conclusions:

• FOBT selection must align with specific colorectal cancer screening program needs.
• Quantitative FIT is the preferred test for scenarios prioritizing detection or balancing detection with resource constraints.
• FITs are superior to gFOBTs for maximizing screening participation, while gFOBTs are only suitable for limited resource scenarios.