FIT helps assess risk of advanced neoplasia before surveillance colonoscopy

Faecal immunochemical test (FIT) appears to provide useful information regarding a patient’s risk of advanced neoplasia and subsequently help physicians decide which patients should be prioritized for a colonoscopy, according to a study.

The study included 766 patients (median age 66.1 years, 49.9 percent men) who completed a two-sample FIT within 90 days of surveillance colonoscopy. Researchers determined the sensitivity of FIT for detection of advanced neoplasia (colorectal cancer or advanced adenoma) in moderate- and high-risk patients at faecal haemoglobin (Hb) thresholds between 2 and 80 μg/g of faecal matter.

Advanced neoplasia was detected in 66 patients (8.6 percent), including five with colorectal cancer. For moderate-risk patients with prior history of adenoma or a significant family history of colorectal cancer, FIT was able to detect advanced neoplasia with a sensitivity that ranged from 73.5 percent at 2 μg Hb/g of faecal matter to 10.2 percent at 80 μg Hb/g of faecal matter.

For high-risk patients with confirmed/suspected genetic syndromes or prior colorectal cancer, FIT showed a similar sensitivity for detecting advanced neoplasia, ranging from 70.6 percent at the lowest positivity threshold of 2 μg Hb/g of faecal matter to 11.8 percent at 80 μg Hb/g of faecal matter.

Factors associated with detection of AN at surveillance colonoscopy in the whole cohort included age (odds ratio [OR], 1.03, 95 percent confidence interval [CI], 1.00–1.06) and FIT Hb result of ≥10 μg Hb/g of faecal matter (OR, 1.81, 95 percent CI, 1.04-3.16).

The findings hold potential clinical implications, as the use of FIT prior to colonoscopy to determine the risk of advanced neoplasia could help to reduce the number of unnecessary colonoscopies.