An evaluation of the SENTiFIT 270 analyser for quantitation of faecal haemoglobin in the investigation of patients with suspected colorectal cancer

Abstract

Abstract Background: An evaluation of SENTiFIT® 270 (Sentinel Diagnostics, Italy; Sysmex, Spain) analyser for the quantitation of faecal haemoglobin (f-Hb) was performed. Methods: The analytical imprecision, linearity, carry over and f-Hb stability were determined. Evaluation of the diagnostic accuracy was performed on 487 patients. Results: Within-run and between-run imprecision ranged 1.7%–5.1% and 3.8%–6.2%, respectively. Linearity studies revealed a mean recovery of 101.1% (standard deviation, 6.7%) for all dilutions. No carry over was detected below 7650 μg Hb/g faeces. Decay of f-Hb in refrigerated samples ranged 0.2%–0.5% per day. f-Hb in patients with advanced colorectal neoplasia (ACRN) (colorectal cancer [CRC] plus advanced adenoma [AA]) were significantly higher than from those with a normal colonoscopy. Sensitivity for ACRN at f-Hb cutoffs from 10 to 60 μg Hb/g faeces ranged from 28.9% (95% confidence interval [CI], 21.7%–37.2%) to 46.5% (95% CI, 38.1%–55%), the specificity ranged from 85% (95% CI, 82.3%–87.3%) to 93.2% (95% CI, 91.2%–94.8%), positive predictive values for detecting CRC and AA ranged from 11.6% (95% CI, 7.6%–17.2%) to 20.6% (95% CI, 13.3%–30.3%) and from 34.7% (95% CI, 28.1%–42%) to 42.3% (95% CI, 32.4%–52.7%), respectively, and the negative predictive value for ACRN ranged from 90.2% (95% CI, 87.9%–92.2%) to 88.4% (95% CI, 86%–90.4%). Using two samples per patient sensitivity increased with a slight decrease in specificity. Conclusions: The analytical and clinical performances of SENTiFIT assay demonstrate a specific and accurate test for detecting ACRN in symptomatic patients and those undergoing surveillance.