Clinical Question

Are fecal immunochemical tests (FITs) superior to guaiac-based fecal occult blood tests (gFOBTs) when screening individuals at average risk for colorectal cancer?

Evidence-Based Answer

FITs are more likely than gFOBTs to detect colorectal cancer or advanced adenomas in individuals at average risk.¹ (Strength of Recommendation = A, consistent, good-quality patient-oriented evidence.)

Practice Pointers

In 2019, colorectal cancer was the fourth most common cancer in the United States and was the fourth highest cause of cancer-related mortality.² Screening with a gFOBT or FIT can find colorectal cancer during the presymptomatic phase or detect advanced adenomas, potential precursors to colorectal cancer. Early identification leads to easier treatments and lower mortality.¹ The authors of the review sought to compare the accuracy of gFOBTs vs. FITs for population-based screening for colorectal cancer and advanced adenomas in individuals at average risk.

The Cochrane review included 63 high-quality studies and more than 3.7 million patients older than 40 years.¹ The included studies used a variety of methodologies, controls, and comparisons, which led the authors to analyze them using two primary constructs. Studies in which participants received both a fecal test and a colonoscopy were termed reference standard: all. Studies that used a sequential screening method in which only a positive fecal screening was followed by colonoscopy were termed reference standard: positive. The authors only included studies that used colonoscopy as the reference standard.