81 Clinical Outcomes Following Prophylactic Total Gastrectomy (PTG) in Patients with Hereditary Diffuse Gastric Cancer (HDGC) Treated at a National Referral Centre

Abstract Introduction Patients with HDGC carry up to a 42% lifetime risk of diffuse gastric cancer. Definitive treatment remains prophylactic total gastrectomy (PTG) but this carries a risk of major complications with mortality reported. We describe the clinicopathological outcomes following PTG at a national referral centre. Method Retrospective review was performed of prospectively collected clinicopathological data for consecutive patients undergoing PTG between 2005 and 2025. Only patients having prophylactic surgery (no invasive disease) were included. Standard surgery consisted of an open posterior vagal-sparing total gastrectomy with D1 lymphadenectomy. D0/D2 lymphadenectomy and/or truncal vagotomy were undertaken in selected cases. Results Sixty patients underwent PTG with a median age of 31 [IQR 25-41]. All PTG were open with 73% undergoing D1 lymphadenectomy and 77% vagal-sparing procedures. The median lymph node yield was 12 nodes [7-20]. The major complication rate (Clavien-Dindo ≥III) was 1.6% with a single late anastomotic leak at the jejuno-jejunal anastomosis. Post-operative length of stay was a median of 8 days [7-9]. The final pathological stage was pT1aN0M0 in 87%, pT0N0M0 in 11% with 1 focus in 1 case demonstrating submucosal invasion (pT1bN0M0, 1.6% of patients, 1/1697 lesions across all cases). No lymph node metastases were observed, and complete gastric mucosal resection was achieved for all. The 5-year estimated overall, and disease-specific survivals were 100% at median follow-up of >6 years. Conclusions PTG remains a robust and effective treatment for patients with HDGC with excellent outcomes achievable in a specialist centre.