Gastric Carcinoma: Diagnosis, Staging, and Treatment.

[BACKGROUND] Gastric carcinoma ranks tenth in incidence among all cancers in men and women in Germany. 5565 women and 9027 men received a diagnosis of gastric carcinoma in Germany in 2022.

[METHODS] The German clinical practice guideline was comprehensively revised with the interdisciplinary participation of German specialty societies under the leadership of the German Society for Gastroenterology, Digestive and Metabolic Disorders, according to the methodological specifications of the Association of Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF).

[RESULTS] The new recommendations promote preventive measures in the presence of risk factors such as hereditary diseases or infection with Helicobacter pylori. Combinations of chemotherapy with immunotherapy, such as nivolumab, pembrolizumab, and tislelizumab, prolong median overall survival compared to chemotherapy alone (e.g., nivolumab plus chemotherapy, 14.4 vs. 11.1 months, HR 0.71) and markedly prolong 5-year survival to 16%. In patients with high claudin18.2 expression, the antibody zolbetuximab, combined with chemotherapy, prolongs median survival to 16.4 vs. 13.4 months (HR 0.77). For patients in good general health, further chemotherapy or biomarker-defined approved second-line (trastuzumab deruxtecan, pembolizumab) or third-line treatment (e.g., trifluridine tipirazole) and advanced molecular-pathological diagnostic testing should be offered at centers for personalized oncology in case of treatment failure. The biomarkers HER2, PD-L1, MSI, and claudin18.2 enable new targeted therapies in palliative situations with long-term improvement in outcome.

[CONCLUSION] The diagnostic evaluation of gastric carcinoma should include high-resolution video endoscopy, and its treatment should be stage-adapted and interdisciplinary. Monoclonal antibodies and immune checkpoint inhibitors are increasingly being used for palliative treatment. The new modifications to the clinical practice guideline will promote the use of uniform strategies for perioperative and palliative treatment and supportive measures.