Perioperative immune checkpoint inhibitor therapy for gastric and gastroesophageal junction cancers: a review of current approaches and future perspectives.

Metastatic gastric and gastroesophageal junction cancers have been treated with chemotherapy, but the landscape of cancer treatment is rapidly shifting towards immune-based therapies. As established by the CheckMate 649 and ATTRACTION-4 trials, combination therapy with fluorouracil, platinum, and nivolumab, an immune checkpoint inhibitor, is now recognized as the standard first-line chemotherapy for HER2-negative gastric and gastroesophageal junction cancer. The potential of immune checkpoint inhibitors extends beyond metastatic disease. For locally advanced gastric and gastroesophageal junction cancer, perioperative chemotherapy with gastrectomy has been regarded as the standard of care, especially in Western nations. Besides, the introduction of immune checkpoint inhibitors as neoadjuvant and adjuvant treatments is currently underway, indicating a significant paradigm shift in the treatment strategies. This review summarizes the clinical developments and future perspectives of immune checkpoint inhibitor therapy with or without chemotherapy as perioperative treatment for gastric, esophageal, and gastroesophageal junction cancer.