{
  "abstract": "Introduction Colonoscopy is the cornerstone of colorectal cancer (CRC) prevention in Lynch syndrome (LS). However, colorectal neoplasia outcomes in LS are heterogeneous and limited by inconsistently reported quality metrics, while benchmarks for neoplasia detection rates remain undetermined. We performed a systematic review and meta-analysis to evaluate pooled neoplasia detection rates in LS and assess demographic, genotype and risk factors for neoplasia development.Methods We searched MEDLINE(R), EMBASE classic+EMBASE, Cochrane library and clinicaltrials.gov until February 2025 to ascertain studies reporting colorectal neoplasia detection rates in LS. The primary outcomes were the pooled adenoma (ADR), advanced adenoma (AADR), serrated lesion (SLDR) and CRC (CRCDR) detection rates. Subgroup analyses were performed to determine risk factors and impact of colonoscopy quality on neoplasia detection rates.Results Thirty-six studies were included, comprising 45,421 colonoscopies in 15,227 LS carriers. The pooled detection rates were: ADR 23.3% (95%CI:20.6-26.3), AADR 5.3% (95%CI:4.5-6.3), SLDR 8.6% (95%CI:6.3-11.7), and CRCDR 2.5% (95%CI:1.9-3.3) ( figure 1), with higher ADR in the proximal colon (16.4% vs. 11.9% distal) and increased proportion of flat adenomas (flat ADR 16.1%). Data on completion rates and bowel preparation were available in 17,692 (39.0%) and 13,963 (30.7%) procedures, respectively.ADR was highest among trial populations in which poor quality or incomplete procedures were excluded (30.7%), followed by prospective (24.0%) and retrospective observational studies (18.5%). Rates of advanced neoplasia were higher among high-risk genotypes (MLH1/MSH2) compared to low-risk variants (MSH6/PMS2): MLH1 [AADR 5.1%, CRCDR 5.1%] and MSH2/EPCAM [AADR 6.3%, CRCDR 4.7%] carriers vs. MSH6 [AADR 3.5%, CRCDR 3.1%] and PMS2 [AADR 4.1%, CRCDR 4.2%], respectively.Conclusions This is the first systematic review and meta-analysis to synthesise neoplasia detection patterns in LS which demonstrate significant variability associated with colonoscopy quality. In addition, our data confirm the distinct gene-specific and phenotypic characteristics of LS-colorectal neoplasia. This highlights the need for routine reporting of high-quality key performance indicators to better contextualise procedural and biological contributors to colorectal carcinogenesis in LS.Abstract P1 Figure 1Forest plot of adenoma detection rate in individuals with Lynch syndrome Adenoma detection rate, expressed as proportions.Abbreviations: AI, artificial intelligence; CE, indigocarmine chromoendoscopy; CI, confidence intervals; LCI, linked colour imaging; NBI, narrow band imaging; WLI, white light imaging",
  "authors": [
    {
      "affiliations": [
        "St. Mark’s Hospital, London, United Kingdom",
        "Imperial College London, London, United Kingdom"
      ],
      "name": "Stephanie Poo"
    },
    {
      "affiliations": [
        "St. Mark’s Hospital, London, United Kingdom"
      ],
      "name": "Nick Dai"
    },
    {
      "affiliations": [
        "Imperial College London, London, United Kingdom"
      ],
      "name": "Amanda Cross"
    },
    {
      "affiliations": [
        "St. Mark’s Hospital, London, United Kingdom",
        "Imperial College London, London, United Kingdom"
      ],
      "name": "Kevin Monahan"
    }
  ],
  "title": "P1 A systematic review and meta-analysis of colorectal neoplasia detection rates in Lynch syndrome",
  "uid": "270d8255-082a-5b9f-8cd9-d1669f612970"
}