Is faecal-immunochemical test useful in patients with iron deficiency anaemia and without overt bleeding?

Both upper and lower endoscopies are indicated in patients with iron deficiency anaemia. However, these examinations are negative in a high proportion of cases.

To assess whether faecal-immunochemical test (FIT) may be useful in selecting patients at higher risk of bleeding lesions in iron deficiency anaemia patients.

Iron deficiency anaemia patients without overt bleeding were prospectively enrolled. All patients performed FIT, and underwent both upper and lower endoscopy. Predictive factors of potential bleeding lesions were evaluated at multivariate analysis.

FIT was positive in 48 (34.3%) out of 140 enrolled patients, and a potential bleeding lesion was present in 63 (45%) patients. An endoscopic lesion was detected more frequently in FIT-positive than -negative patients (79.2% vs 27.2%; p<0.0001), at both upper endoscopy (52.1% vs 18.5%; p=0.0002) and colonoscopy (33.3% vs 8.7%; p=0.001). At multivariate analysis, FIT was found to be an independent predictor of both bleeding lesions (OR=9.5; 95% CI: 4.1-22; p<0.001) and cancer (OR=4.0, CI: 1.1-15; p=0.029).

FIT positive-iron deficiency anaemia patients without overt bleeding are at increased risk to present with a bleeding lesion at endoscopy, including cancer. FIT positivity in this setting could be useful to prioritize urgent endoscopy.