HIGH RISK PATIENTS SUSPICIOUS OF LYNCH SYNDROME; ARE THEY BEING CLASSIFIED CORRECTLY AND RECEIVING APPROPRIATE SURVEILLANCE?

Aims Lynch Syndrome (LS) is diagnosed by genetic testing of mismatch repair genes. However, before genetic testing, patients are categorised by clinical criteria (Amsterdam/Bethesda). The Mater Hospital (MMUH) cohort of patients without genetic testing but meeting the clinical criteria are categorised as ‘LS Unconfirmed’ in the high-risk database and surveillance is arranged accordingly.

1. To evaluate patients categorised as ‘LS unconfirmed’ in the MMUH familial CRC clinic.

2. Critically examine the accuracy of this categorisation and whether all patients are under the same surveillance.

3. To assess the benefits of switching to more recent guidelines for surveillance.

Methods Retrospective review of the pedigrees of all patients documented as ‘LS Unconfirmed’ in the MMUH high risk database to confirm risk level. Reclassification of patient’s risk levels from the original protocol to the newer Royal Marsden guidelines.

Results N= 184. In the case of 30 patients the pedigree was absent. 9 patients were dead. 2 patients were Gene+, 2 patients Gene-. 2 patients had polyposis syndrome. Only 60% had a patient with a first degree relative (FDR) with CRC. 9.8% had an FDR with diagnosed LS. 64.7% compliant with surveillance. 49% having yearly/2 yearly colonoscopies and 25% having yearly/2 yearly OGDs. Recategorisation saw most patients move to a 5 yearly surveillance plan starting at different ages, while 28 required one off colonoscopies and 11 were of average risk.

Conclusions New guidelines redefine patient’s level of risk and significantly change interval for surveillance. This study highlights the need to adopt international guidelines and updates to guarantee appropriate surveillance.