Part I. Epidemiology -- Family History and the Risk of Breast and Gastric Cancer -- Worldwide CDH1 Germline Mutation Frequency and the Transhormesis Hypothesis -- Hereditary Lobular Breast Cancer: A Newly Defined Syndrome -- Part II. Genetics -- Genetic Counseling and Prevention in Families at High Risk for HDGC and Other Hereditary Syndromes -- CTNNA1, a New HDGC Gene: Inactivating Mechanisms and Driven Phenotypes -- Revisiting the Biological and Clinical Impact of CDH1 Missense Variants -- Other Syndromes and Genes Associated with Gastric Cancer Predisposition -- Computer-Assisted Interpretation of Cancer-Predisposing Variants -- Part III. Pathology -- Histopathology of Hereditary Diffuse Gastric Cancer: From Grossing and 3D Microscopy to Immunophenotypic and Molecular Profiling -- HER2 Testing in Breast and Gastric Cancer with CDH1 Germline Mutations -- Pathology and Somatic Alterations in Hereditary Lobular Breast Cancers -- Part IV. Endoscopy and Imaging -- Endoscopy:Is there Anything New? -- Endoscopic Surveillance and Pathology of Biopsies in CDH1, CTNNA1 and HDGC-Like Families -- Lobular Carcinoma of the Breast: Spectrum of Imaging Findings and New Emerging Technologies on the Horizon -- Part V. Surgery -- Prophylactic Total Gastrectomy: Techniques -- Prophylactic Total Gastrectomy: How Many? -- Hereditary Lobular Breast Cancer Syndrome: Role of Surgery -- Breast Reconstruction -- Part VI. New Issues -- Psychological Burden and Preferences in CDH1 Mutation Carriers: Beyond the Cancer Diagnosis -- Drug Repurposing in Gastric Cancer: Current Status and Future Perspectives -- The Chemoprevention of Hereditary Diffuse Gastric Cancer -- Malformations and Malformative Syndromes Associated with CDH1 -- Hereditary Breast Cancer Non-CDH1 Associated -- Part VII. Patient Advocacy -- My Hereditary Gastric Cancer -- Hereditary Breast Cancer Syndrome, My Experience -- Part VIII. Miscellaneous -- β-Hemoglobinopathies and Early Onset of Cancers in Adulthood. Epidemiology in Southeastern Asia & Brunei with Emphasis for Prevention and Treatment.