Minimal Access Therapy and Training Unit (MATTU), Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK.
Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK.
Colorectal Dis. 2024 Sep;26(9):1711-1719. doi: 10.1111/codi.17132. Epub 2024 Aug 13.
Faecal immunochemical tests (FIT) are highly sensitive for colorectal cancer (CRC) detection. Little evidence exists regarding repeat FIT. The repeat FIT (RFIT) study aimed to determine whether second and third FIT provide reassurance and improve CRC or significant bowel disease (SBD) identification.
This was a prospective observational study. Patients recruited from urgent referrals returned three FIT and underwent colonoscopy. Chi-square tests compared categorical data. Diagnostic accuracy variables (sensitivity/specificity/positive predictive value [PPV]/negative predictive value [NPV]) were calculated for one, two and three FIT (95% CI). Three negative FIT (<10 μg Hb/g of faeces [μg/g]) groups (one, two, three) were compared with positive groups (one or more FIT ≥10 μg/g). CRC and SBD detection rates were compared by strategy.
A total of 460 patients (mean age: 66.8 years, 233 males and 227 females, 23 CRC, 80 SBD) were included in the study. For one, two and three negative FIT, CRC sensitivity remained static (95.7%); specificity (44.6%, 40.7% and 38.4%) and NPV decreased (99.5%, 99.4% and 99.4%). For SBD, sensitivity increased (78.8%, 83.8% and 86.3%), specificity decreased (47.4%, 43.7% and 41.6%) and NPV increased (91.4%, 92.7% and 93.5%). In one, two and three positive FIT groups, CRC detection was 8.3%,16.1% and 20.9%. CRC mean FIT was 150 μg/g, <6 μg/g for benign pathology.
One or more negative FIT increases the sensitivity for CRC/SBD. Repeating FIT provides greater differentiation of patients with and without CRC/SBD compared to single FIT but is associated with decreased specificity and PPV. Multiple negative FIT may offer reassurance; however, application of repeating FIT may be restricted given the associated increase in investigations.
粪便免疫化学检测（FIT）对结直肠癌（CRC）的检测具有高度敏感性。关于重复 FIT 的证据很少。重复 FIT（RFIT）研究旨在确定第二次和第三次 FIT 是否提供保证并改善 CRC 或显著肠道疾病（SBD）的识别。
这是一项前瞻性观察性研究。从紧急转诊中招募的患者返回了三次 FIT，并进行了结肠镜检查。卡方检验用于比较分类数据。计算了一次、两次和三次 FIT 的诊断准确性变量（敏感性/特异性/阳性预测值[PPV]/阴性预测值[NPV]）（95%CI）。将三个阴性 FIT（粪便中血红蛋白<10μg/g [μg/g]）组（一个、两个、三个）与阳性组（一个或多个 FIT≥10μg/g）进行比较。通过策略比较 CRC 和 SBD 的检出率。
共纳入 460 例患者（平均年龄：66.8 岁，男性 233 例，女性 227 例，CRC23 例，SBD80 例）。对于一次、两次和三次阴性 FIT，CRC 的敏感性保持不变（95.7%）；特异性（44.6%、40.7%和 38.4%）和 NPV 降低（99.5%、99.4%和 99.4%）。对于 SBD，敏感性增加（78.8%、83.8%和 86.3%），特异性降低（47.4%、43.7%和 41.6%），NPV 增加（91.4%、92.7%和 93.5%）。在一次、两次和三次阳性 FIT 组中，CRC 的检出率分别为 8.3%、16.1%和 20.9%。CRC 的平均 FIT 为 150μg/g，良性病变<6μg/g。
一次或多次阴性 FIT 可提高 CRC/SBD 的敏感性。与单次 FIT 相比，重复 FIT 可更好地区分有或无 CRC/SBD 的患者，但特异性和 PPV 降低。多次阴性 FIT 可能提供保证；然而，鉴于相关检查的增加，重复 FIT 的应用可能会受到限制。
