Treatment options for oligometastatic gastric cancer

Abstract

Background: At the time of diagnosis of gastric cancer approximately one third of patients already have metastases. It is important to differentiate between oligometastasis and the diffuse metastatic situation. For the first time the definition of oligometastasis has been integrated into the German S3 guidelines. Objective: Can multimodal treatment with tumor resection and metastasectomy combined with perioperative chemotherapy, increase the chances of survival in oligometastatic patients? Material and methods: In this review article the data situation of the current literature is discussed. Results: The Dutch D1/D2 trial reported an increased median survival for a subgroup of patients with single metastasis who underwent resection. Multimodal treatment with resection doubled the median survival of oligometastatic patients in the German AIO-FLOT 3 study and as a consequence, the AIO-FLOT 5 (RENAISSANCE) trial was designed. Patients with oligometastatic gastric and esophagogastric junction cancer are randomized after chemotherapy to either undergo resection followed by adjuvant chemotherapy or to undergo definitive chemotherapy. Further randomized trials investigate the benefit of antibodies and immune checkpoint inhibitors in locoregional and advanced metastatic gastric cancer with promising results. Conclusion: The results of the ongoing randomized trials will show if oligometastatic patients benefit from a multimodal treatment with resection. The clear definition of the oligometastatic state, assessment of the response to neoadjuvant chemotherapy and realistic estimation of the R0 resectability will be useful for patient selection.