Diagnostic Value of Fecal Calprotectin as a Screening Biomarker for Gastrointestinal Malignancies

Background: Calprotectin in feces seems to be a more sensitive marker for gastrointestinal (GI) cancers thanfecal occult blood, but its specificity may be too low for screening average risk populations. This study aims atevaluating the diagnostic value of fecal calprotectin as a screening biomarker for GI malignancies. Materialsand
Methods: In a case-control study, 100 patients with GI malignancies (50 patients with colorectal cancer and50 patients with gastric cancer) and 50 controls were recruited in Tabriz Imam Reza and Sina hospitals duringa 24-month period. One to two weeks after the last endoscopy/colonoscopy, fecal specimens were collected bythe patients and examined by ELISA method for quantitative measurement of calprotectin content. The resultswere compared between the three groups.
Results: The mean fecal calprotectin level was 109.1±105.3 (2.3-454.3,median:74), 241.1±205.2 (3.4-610.0, median:19.3) and 45.9±55.1μg/g (1.3-257.1, median:19.3) in gastric cancer,colorectal cancer and control group, respectively, the differences being significant (p<0.001) and remaining afteradjustment for age. The optimal cut-off point for fecal calprotectin was ≥75.8μg/g for distinguishing colorectalcancer from normal cases (sensitivity and specificity of 80% and 84%, respectively). This value was ≥41.9μg/gfor distinguishing gastric cancer from normal cases (sensitivity and specificity of 62%).
Conclusions: Our resultsrevealed that fecal calprotectin might be a useful and non-invasive biomarker for distinguishing colorectal cancerfrom non-malignant GI conditions. However, due to low sensitivity and specificity, this biomarker may not helpphysicians distinguishing gastric cancer cases from healthy subjects.