Multicenter cohort retrospective clinical study to assess the impact of complete pathomorphological tumor response on survival in patients with locally advanced gastric and esophagogastric junction cancer (trial protocol)

Introduction. Gastric cancer remains the leading cause of cancer-related morbidity and mortality worldwide and in Russia. In recent years, significant progress in treatment has been made through the use of modern neoadjuvant/perioperative therapy techniques. The grade of tumor pathomorphological response is a direct indicator of the effectiveness of neoadjuvant therapy, but the correlation between this response and long-term treatment outcomes varies significantly among different authors. The impact of a complete morphological tumor response on the patient’s treatment strategy and disease prognosis is a crucial scientific and practical challenge, and it remains a subject of debate.

Material and Methods. The study is planned as a multicenter, cohort, non-interventional, retrospective, open clinical trial. The studied treatment approach is neoadjuvant/ perioperative therapy followed by radical surgery for gastric and esophagogastric junction cancer in patients with complete tumor pathomorphological response after neoadjuvant therapy. The study is planned to include 200–250 patients who meet the following main criteria: morphologically verified gastric cancer (adenocarcinoma) and esophagogastric junction (Siewert III); clinical stage I–IVA, M0; neoadjuvant therapy (at least 1 cycle of chemotherapy) and radical surgery; pathomorphological stage of T0N0/N1–3. The primary endpoint (the main goal of the study) is to assess the 3-year overall survival rate. The total duration of the study will be 12 months. To analyze the treatment outcomes, an original database will be created using the Microsoft Excel 2010 program. Statistical analysis will be performed using the SPSS program, version 23.0. The study will be conducted in accordance with the principles of the Declaration of Helsinki, international and Russian rules for conducting scientific research in the field of medicine, and the legislation of the Russian Federation, and it has been approved by the Ethics Committee of the A.F. Tsyb Medical Research Center.

Results. For the first time in Russia, a multicenter retrospective clinical study will be conducted to assess the treatment outcomes in patients with locally advanced stomach cancer and esophagogastric junction cancer, provided that the tumor has a complete pathomorphological response after neoadjuvant therapy. The collected data (approximately 250 cases) is expected to be the largest in the world for this category of clinical observations. For the first time, representative data will be obtained based on the treatment outcomes of the Russian population of gastric cancer patients, including in real-world clinical settings.

Conclusion. It is expected that the results obtained during the implementation of this study will have both important scientific significance and practical application, including the possibility of using them in the national clinical guidelines.

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