Iovanescu Dana, Frandes Mirela, Lungeanu Diana, Burlea Amelia, Miutescu Bogdan P, Miutescu Eftimie
Department of Gastroenterology, Faculty of Medicine, Pharmacy and Dental Medicine, "Vasile Goldis" West University of Arad.
Department of Functional Sciences, "Victor Babes" University of Medicine and Pharmacy of Timisoara.
Onco Targets Ther. 2016 Nov 4;9:6819-6828. doi: 10.2147/OTT.S122425. eCollection 2016.
Employing colonoscopy, the gold standard in colorectal cancer (CRC) diagnosis testing, for CRC screening presents a significant risk of complications. Alternative methods with a lower invasive-level and fewer risks are proposed in combination, though each with lower diagnosis performance when applied separately. The main objective of this cross-sectional pilot study was to evaluate the feasibility of a CRC screening program using combined flexible sigmoidoscopy and fecal-immunochemical test (FIT).
The patient population consisted of 2,201 consecutive-case symptomatic patients attending the gastroenterology outpatient clinic with mild complaints between 2012 and 2014. They were referred for FIT. A sample of 252 individuals underwent a subsequent colonoscopy, blind to FIT results, and theoretical sigmoidoscopy was simulated. On a subsample of 57 patients, real sigmoidoscopy was additionally performed. Prior probabilities in terms of patients' compliance and CRC prevalence were estimated, together with predictive ability of FIT and sigmoidoscopy in screening population. We assessed the merit of a screening strategy employing two-stage serial multiple testing: a) first stage by combining two parallel tests, that is, flexible sigmoidoscopy and FIT and b) colonoscopy as the second diagnosis test. The scheme was validated using the actual predictive values derived from the study population.
Colonoscopy found 75 (29.76%) individuals with advanced neoplasia. FIT was positive in 30.3% of advanced neoplasia cases, while between 23.73% and 28.28% met the theoretical sigmoidoscopy simulation criteria, with good concordance between real and theoretical sigmoidoscopy. The colonoscopy referral compliance rate was 52% among FIT-positives. Sensitivity and specificity of the first-stage test combination were better than sigmoidoscopy alone (McNemar test: <0.001). Negative predictive values for low prevalence levels were between 81.5% and 90.12%.
Combining less resource challenging and less invasive testing procedures is worthwhile in colorectal neoplasia detection, improving sensitivity and specificity of either test alone, and leading to better posterior probabilities in usual screening scenarios.
采用结肠镜检查这一结直肠癌（CRC）诊断检测的金标准进行CRC筛查存在显著的并发症风险。虽然单独应用时每种方法的诊断性能较低，但已提出结合使用侵入性较低且风险较小的替代方法。这项横断面试点研究的主要目的是评估使用联合软性乙状结肠镜检查和粪便免疫化学检测（FIT）进行CRC筛查计划的可行性。
患者群体包括2012年至2014年间连续就诊于胃肠病门诊、有轻微症状的2201例有症状患者。他们被转诊进行FIT检测。252名个体随后接受了结肠镜检查，检查时对FIT结果不知情，并模拟了理论上的乙状结肠镜检查。在57例患者的子样本中，额外进行了实际的乙状结肠镜检查。估计了患者依从性和CRC患病率方面的先验概率，以及FIT和乙状结肠镜检查在筛查人群中的预测能力。我们评估了采用两阶段系列多重检测的筛查策略的优点：a）第一阶段通过结合两个平行检测，即软性乙状结肠镜检查和FIT，以及b）结肠镜检查作为第二次诊断检测。使用从研究人群得出的实际预测值对该方案进行了验证。
结肠镜检查发现75例（29.76%）患有高级别瘤变。FIT在30.3%的高级别瘤变病例中呈阳性，而在23.73%至28.28%的病例中符合理论上的乙状结肠镜检查模拟标准，实际乙状结肠镜检查与理论乙状结肠镜检查之间具有良好的一致性。FIT阳性者中结肠镜检查转诊依从率为52%。第一阶段检测组合的敏感性和特异性优于单独的乙状结肠镜检查（McNemar检验：<0.001）。低患病率水平的阴性预测值在81.5%至90.12%之间。
在结直肠肿瘤检测中，结合资源需求较少且侵入性较小的检测程序是值得的，可提高单独任何一种检测的敏感性和特异性，并在常规筛查情况下得出更好的后验概率。
