Abstract 3323: The feasibility for detecting hereditary genetic findings of familial gastric cancer

Background: Multiplex gene panel tests using next-generation sequencing has currently been clinically available for various cancer patients including gastric cancer in Japan. The original purpose of the Multiplex gene panel tests is to find actionable genetic alterations which might correlate with promising therapeutic antitumor drugs. Accordingly, secondary genetic findings as germline mutation which is associated with hereditary disease may also be detectable by the Multiplex gene panel tests. It has been reported that familial cancers represent around 5%–10% of all cancer patients. Gastric cancer is one of popular cancers in Japan. The prediction of patients with familial gastric cancer (FGC) before the multiplex gene panel tests might be important for the gene consultation for the patients and their family. Objective: The aim of study is to clarify the characteristic clinico-pathologic features of FGC to predict the possibility of hereditary gastric cancer. Patients and Methods: A total of 2301 gastric cancer patients who received gastrectomy at our department was enrolled in this study. We classified FGCs into 2 categories by modification of International Gastric Cancer Linkage Consortium (IGCLC) which excluded pathogenic types, as follows, group A: gastric cancer in an individual under the age of 40; group B: two gastric cancer cases in a family regardless of age. In contrast, the most gastric cancers were sporadic, which was classified as group C. The clinicopathological factors including E-cadherin and p53 expression by immunostaining, was retrospectively compared among 3 groups. Results: One hundred and fifty-two cases (6.6%) of 2301 patients were classified as FGCs (group A: 71 cases; group B: 81 cases), whereas the remaining 2149 patients were classified as group C (93.4%). Female (43.4%) and diffuse-type gastric cancer (57.2%) was significantly (p Conclusion: Young age ( Citation Format: Sadaaki Nishimura. The feasibility for detecting hereditary genetic findings of familial gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3323.