Evaluation of quantitative stool occult blood test in opportunistic screening for colorectal cancer / 中华健康管理学杂志

Objective:To evaluate the efficacy of quantitative fecal immunochemical test (fecal immunochemical test, FIT) in the screening of colorectal cancer and precancerous lesions.Methods:47 243 patients who underwent quantitative FIT screening for colorectal cancer in the Health Management Department of Shenzhen People′s Hospital from January 2019 to October 2020 were enrolled as subjects. Colonoscopy was recommended for patients with positive quantitative FIT. A follow-up was done after one year to compare the results of the quantitative FIT positive group and the negative group after colonoscopy. Data were adjusted by propensity score matching method and a receiver operating characteristic curve ( ROC) was established to evaluate the diagnostic effect of quantitative FIT combined with colonoscopy on colorectal cancer and precancerous lesions. Results:A hemoglobin concentration>100 μg/L was set as a positive threshold. There were 2 472 positive cases of quantitative FIT, and the positive rate was 5.23%. After one-year follow-up, 284 patients had completed colonoscopy; the colonoscopy compliance was 11.49%. Of the negative population, 1 493 patients selected colonoscopy within one year. Compared with the results of gold standard colonoscopy, the sensitivity and specificity of quantitative FIT for screening for advanced adenoma and cancer were 26.53% and 86.54%, respectively. The sensitivity for colorectal cancer screening was 94.44% and screening for advanced adenoma was 22.77%. After propensity score matching, there were 256 FIT positive patients and 705 FIT negative patients. Colorectal cancer was the outcome variable, while FIT combined with colonoscopy, age combined with colonoscopy, and FIT combined with age combined with colonoscopy were the diagnostic indicators. The areas under the curve were 0.841(95% CI:0.778-0.904), 0.677(95% CI: 0.535-0.820), and 0.882(95% CI:0.807-0.958), respectively. Conclusion:Quantitative FIT has a high susceptibility to opportunistic screening for colorectal cancer, and a low sensitivity to advanced adenoma. At the same time, quantitative FIT combined with colonoscopy has a good diagnostic accuracy for colorectal cancer, which is better than the effect of using age as a cut-off point for colonoscopy. Quantitative FIT combined with age and colonoscopy has the best effect on screening for colorectal cancer. Quantitative FIT has a high sensitivity to colorectal cancer and a low sensitivity to advanced adenoma.

The novel latex agglutination turbidimetric immunoassay system for simultaneous measurements of calprotectin and hemoglobin in feces

BACKGROUND/AIMS: Fecal calprotectin (Fcal) as well as the fecal immunochemical test (FIT) are useful biomarkers for detecting activity and mucosal healing in inflammatory bowel diseases. Here, we report the performance of simultaneous measurements of Fcal and FIT for ulcerative colitis (UC) patients using the newly-developed latex agglutination turbidimetric immunoassay (LATIA) system. METHODS: Fcal and hemoglobin were measured by the LATIA system in 152 UC patients who underwent colonoscopy. Fcal was also quantified with a conventional enzyme-linked immunosorbent assay (ELISA). Fecal markers were evaluated in conjunction with the mucosal status of UC, which was assessed via the Mayo endoscopic subscore (MES) classification. RESULTS: The LATIA system could quantify calprotectin and hemoglobin simultaneously with the same fecal samples within 10 minutes. The values of the Fcal-LATIA closely correlated with those of the Fcal-ELISA (Spearman rank correlation coefficient, r=0.84; P<0.0001). The values of Fcal for each assay and the FIT all significantly correlated with the MESs (Spearman rank correlation coefficient, Fcal-LATIA: r=0.58, Fcal-ELISA: r=0.55, and FIT: r=0.72). The mucosal healing predictability (determined by an MES of 0 alone) of the Fcal-LATIA, Fcal-ELISA, and FIT-LATIA with the cutoffs determined by receiver operating characteristic curve analysis was 0.79, 0.78, and 0.92 for sensitivity, respectively, and 0.78, 0.69, and 0.73 for specificity, respectively. CONCLUSIONS: The performance of the novel Fcal-LATIA was equivalent to that of the conventional Fcal assay. Simultaneous measurements with FITs would promote the clinical relevance of fecal biomarkers in UC.

Fecal Immunochemical Test and Fecal Calprotectin Results Show Different Profiles in Disease Monitoring for Ulcerative Colitis

BACKGROUND/AIMS: Both fecal immunochemical test (FIT) and fecal calprotectin (Fcal) results are useful biomarkers for ulcerative colitis (UC). However, the situations in which each marker should be used are largely unknown. METHODS: A total of 110 colonoscopy intervals of UC patients were assessed, and correlations between changes in colonoscopic findings and changes in the two aforementioned fecal markers were examined. RESULTS: Among patients with mucosal healing (MH) and negative FIT or Fcal results at the initial colonoscopy, FIT and Fcal findings exhibited accuracies of 93% (38/41) and 79% (26/33), respectively, for predicting the results of the subsequent examination. Among the 24 patients who showed endoscopic activity at the precedent colonoscopy and MH at the subsequent examination, positive-to-negative conversion of FIT and Fcal findings at the subsequent examination was observed in 92% (12/13) and 62% (8/13) of patients, respectively. Among the 43 patients who showed endoscopic activity at both the precedent and subsequent examinations, Fcal findings reflected the change in endoscopic activity better than FIT results (r=0.59, p<0.0001 vs r=0.30, p=0.054). CONCLUSIONS: The FIT is useful for confirming MH and the occurrence of relapse. In contrast, Fcal is useful for monitoring the mucosal status of patients with active inflammation.