183 Management of Patients with Hereditary Diffuse Gastric Cancer (HDGC) at Leeds Teaching Hospitals Trust (LTHT): A Clinical Audit

Abstract Aim Is mainstream genetic testing for HDGC (CDH1) effective within the setting of an UGI Cancer MDT? Method A retrospective analysis from 2009-2019 identified failures to refer eligible patients for CDH1 testing, and led to a collaboration between UGI, Oncology and Clinical Genetics services to mainstream genetic testing for HDGC within the UGI Cancer service. A Standard Operating Procedure (SOP) was introduced, and outcomes re-evaluated. Results In the 10 years prior to introduction of the CDH1 SOP, 17 patients with confirmed diffuse type gastric cancer fulfilled CDH1 testing criteria. A further 7 patients did not have histological subtype recorded. 12/17 patients (70%) were referred to Clinical Genetics and 10 (58%) underwent CDH1 testing. 3 patients were diagnosed with a pathogenic CDH1 mutation. In the 2.5 years following introduction of the SOP, 25 patients with diffuse type gastric cancer fulfilled CDH1 testing criteria and had this documented in the MDT minutes. 15 patients were seen at our institution and 13/15 (87%) underwent mainstream CDH1 testing. 3 patients were diagnosed with a pathogenic CDH1 mutation. The remaining 10 patients were seen at peripheral centres where mainstream testing is not currently available, only 2 (20%) patients were referred to Clinical Genetics for consideration of CDH1 testing. Conclusions Mainstream genetic testing for HDGC (CDH1) within an UGI Cancer service is feasible and can lead to improved uptake of CDH1 testing for eligible patients. There is scope to widen access to mainstream testing and improve referral pathways in centres where this is not available.