937 Adherence to MMR Reporting Standards in Newly Diagnosed Colorectal Cancer as Part of the Lynch Syndrome Workup Pathway: A Closed Loop Audit
P Sonoo, Z Oo, C BoereboomAbstract
Aim
Lynch syndrome is an inherited condition caused by mutations in DNA mismatch repair (MMR) genes, which significantly increases the risk of colorectal, ovarian, endometrial, and small bowel cancers. According to NICE guidelines, individuals diagnosed with colorectal cancer (CRC) should undergo screening for Lynch syndrome through immunohistochemistry (IHC) testing for MMR proteins or microsatellite instability (MSI). Early identification of Lynch syndrome can guide personalised management strategies. This re-audit evaluates the Trust's adherence to the recommended Lynch screening pathway.
Method
Patients diagnosed with CRC between March and April 2024 were identified from multidisciplinary team (MDT) meeting records. Data collected from electronic patient records included patient demographics, diagnosis dates, TNM staging, IHC MMR results, and additional tests for BRAF and MLH1 hypermethylation. Reporting dates for these tests were also reviewed.
Results
32 cases were reviewed, with 100% undergoing MMR testing, compared to 97% in the initial audit. The average time from biopsy to histology results was 8 days (range 2-22), an improvement from 8.6 days (range 4-32) previously. MMR results were reported within an average of 4.3 days, with 97% reported within 10 days, up from 90% in the first audit. Four patients showed MMR deficiencies, with three undergoing additional BRAF and MLH1 methylation testing. The time between MMR and MLH1 results significantly improved, averaging 91 days, compared to 251 days in the previous audit.
Conclusions
The Trust’s adherence to Lynch syndrome screening has improved, now meeting NICE targets. Continued audits are necessary to ensure sustained compliance with national guidelines.