ColonSys: an AI-powered risk stratification tool for improving FIT-based bowel cancer screening diagnostic yield

**需要：**英国的肠癌筛查计划(BCSP)已经通过改进的诊断方法-粪便免疫化学测试(FIT)而发生了革命性的变化。FIT很容易进行(只需要一个样本)，因此筛查参与率从59.4%增加到了50岁的合格成年人的67.5%。任何超过预先确定的FIT阈值的参与者都会被转介到结肠镜检查，以确定任何医学上可操作的出血原因，如结直肠癌(CRC)或癌前病变(息肉)。与传统的愈创木酚粪便血红蛋白(f-Hb)检测相比，FIT的灵敏度提高了，转诊到结肠镜检查的数量正在上升。FIT有一些公认的弱点；大约45%的接受结肠镜检查的参与者既没有结直肠癌，也没有腺瘤。然而，更令人担忧的是，间歇性癌症(在两次合适的筛查之间发现的癌症)约占确诊肠癌的50%。间歇性癌症的高比例可以用高的阳性f-Hb匹配阈值(英格兰为120微克/克，苏格兰为80微克/克)来解释。最近的模型表明，NHS England Fit阈值120微克/克可能意味着超过52%的结直肠癌和75%的高危腺瘤可能被遗漏。英国肠癌和领先的临床医生建议将FIT阈值降低到20微克/克以便于更早地发现结直肠癌，但这可能会使每年进行结肠镜检查的次数从65万次增加到150万次。结肠镜检查是一种昂贵的侵入性程序(每次结肠镜检查约550 GB)。此外，在新冠肺炎大流行期间，还有额外的动力来减少不必要的感染控制程序和工作人员/患者在医院的互动，同时通过更明智地使用关键资源来提高国民保健系统的效率。因此，在提高FIT的诊断效率和避免不必要的结肠镜检查方面存在着重要而紧迫的**需求。**解决方案：**高级专家系统有限公司(AES)已与邓迪大学和大学医院考文垂及沃里克郡中部地区NHS信托基金的临床学者一起开发了一个基于人工智能的软件平台‘COLONSY’，以在其他风险因素的背景下解释FIT结果。作为一个多元分层模型，COLONSY根据风险、随着从高危患者被快速追踪以进行进一步调查，到没有下次合适的筛查被推迟的风险的患者的梯度。ColorSys将使BCSP更加高效，只有高危患者才需要结肠镜检查。**及时性：**由于新冠肺炎，有了额外的动力来减少不必要的医院就诊，提高国民保健系统的效率。

**NEED:** The UK's Bowel Cancer Screening Programme (BCSP) has been revolutionised by improved diagnostic methodology, the Faecal Immunochemical Test (FIT). FIT is easy to undertake (only one sample required), and so screening participation has increased from 59.4% to 67.5% of eligible adults aged \>50 years.Any participant exceeding a pre-determined FIT threshold value that is universally applied to all samples screened is referred for colonoscopy to identify any medically actionable cause of bleeding i.e., colorectal cancer (CRC) or a precancerous adenoma (polyp).Coupled to increased sensitivity of FIT vs. traditional guaiac-based faecal haemoglobin (f-Hb) detection, the number of referrals to colonoscopy is rising.There are recognised weaknesses with FIT; ~45% of participants undergoing colonoscopy have neither CRC nor adenomas.More worryingly however is that interval cancers (cancers that are detected between FIT screening rounds) account for ~50% of diagnosed bowel cancers. The high proportion of interval cancers can be explained by the high positive f-Hb FIT threshold (120 µg/g in England: 80 µg/g in Scotland). Recent modelling suggests that the NHS England FIT threshold of 120 µg/g could mean over 52% of CRC and 75% of high-risk adenomas may be missed.Bowel Cancer UK and leading clinicians have recommended that the FIT threshold should be lowered to 20 µg/g to facilitate earlier detection of CRC, but this could increase the number of colonoscopies being performed from 650,000 to as many as 1.5 million procedures annually.Colonoscopy is a costly, invasive procedure (c.£550 per colonoscopy). Moreover, during the Covid-19 pandemic, there is additional impetus to reduce unnecessary procedures and staff/patient hospital interactions for infection control, whilst making the NHS more efficient by using critical resources more wisely.There is thus a significant and pressing **unmet need** for improving the diagnostic yield from FIT and avoiding unnecessary colonoscopy.**SOLUTION:** Advanced Expert Systems Ltd (AES) have joined clinical academics from the University of Dundee and University Hospitals Coventry & Warwickshire Midlands NHS Trust to develop an AI-based software platform 'ColonSys' to interpret FIT result in the context of other risk factors.As a multivariate stratification model, ColonSys optimises clinical resources by risk, with a gradient from high-risk patients being fast-tracked for further investigation, to patients with no risk having their next FIT screen delayed.ColonSys will make BCSPs more efficient, with only high-risk patients requiring colonoscopy.**TIMELINESS:** Due to Covid-19, there is additional impetus to reduce unrequired hospital visits and improve NHS efficiency.