Hereditary Cancer in Clinical Practice (May 2022)

Lynch syndrome testing of colorectal cancer patients in a high-income country with universal healthcare: a retrospective study of current practice and gaps in seven australian hospitals

  • Julia Steinberg,
  • Priscilla Chan,
  • Emily Hogden,
  • Gabriella Tiernan,
  • April Morrow,
  • Yoon-Jung Kang,
  • Emily He,
  • Rebecca Venchiarutti,
  • Leanna Titterton,
  • Lucien Sankey,
  • Amy Pearn,
  • Cassandra Nichols,
  • Skye McKay,
  • Anne Hayward,
  • Natasha Egoroff,
  • Alexander Engel,
  • Peter Gibbs,
  • Annabel Goodwin,
  • Marion Harris,
  • James G Kench,
  • Nicholas Pachter,
  • Bonny Parkinson,
  • Peter Pockney,
  • Abiramy Ragunathan,
  • Courtney Smyth,
  • Michael Solomon,
  • Daniel Steffens,
  • James Wei Tatt Toh,
  • Marina Wallace,
  • Karen Canfell,
  • Anthony Gill,
  • Finlay Macrae,
  • Kathy Tucker,
  • Natalie Taylor

DOI
https://doi.org/10.1186/s13053-022-00225-1
Journal volume & issue
Vol. 20, no. 1
pp. 1 – 8

Abstract

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Abstract Background To inform effective genomic medicine strategies, it is important to examine current approaches and gaps in well-established applications. Lynch syndrome (LS) causes 3–5% of colorectal cancers (CRCs). While guidelines commonly recommend LS tumour testing of all CRC patients, implementation in health systems is known to be highly variable. To provide insights on the heterogeneity in practice and current bottlenecks in a high-income country with universal healthcare, we characterise the approaches and gaps in LS testing and referral in seven Australian hospitals across three states. Methods We obtained surgery, pathology, and genetics services data for 1,624 patients who underwent CRC resections from 01/01/2017 to 31/12/2018 in the included hospitals. Results Tumour testing approaches differed between hospitals, with 0–19% of patients missing mismatch repair deficiency test results (total 211/1,624 patients). Tumour tests to exclude somatic MLH1 loss were incomplete at five hospitals (42/187 patients). Of 74 patients with tumour tests completed appropriately and indicating high risk of LS, 36 (49%) were missing a record of referral to genetics services for diagnostic testing, with higher missingness for older patients (0% of patients aged ≤ 40 years, 76% of patients aged > 70 years). Of 38 patients with high-risk tumour test results and genetics services referral, diagnostic testing was carried out for 25 (89%) and identified a LS pathogenic/likely pathogenic variant for 11 patients (44% of 25; 0.7% of 1,624 patients). Conclusions Given the LS testing and referral gaps, further work is needed to identify strategies for successful integration of LS testing into clinical care, and provide a model for hereditary cancers and broader genomic medicine. Standardised reporting may help clinicians interpret tumour test results and initiate further actions.

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