Adjuvant Treatments for Localized Advanced Gastric Cancer: Differences among Geographic Regions

After much debate, adjuvant therapy has become the standard of care worldwide for resected localized gastric cancer. However, geographic differences exist in standard adjuvant treatments: postoperative chemoradiation in North America, perioperative chemotherapy in the United Kingdom, and postoperative chemotherapy in East Asia. Now that D2 gastrectomy has been recognized as the optimal surgery for localized gastric cancer in the West as well as in Asia, the standard adjuvant treatments used in the West may need to be reconsidered. One of the most important issues in adjuvant therapy for localized gastric cancer is how to improve the clinical outcomes of current standard treatments. Recent Cancer and Leukemia Group B (CALGB) and AMC studies suggest that simply intensifying chemotherapy by adding more agents or prolonging treatment duration is insufficient. However, new strategies like early initiation of chemotherapy and/or intraperitoneal chemotherapy may further improve the current standard adjuvant therapy. In the era of targeted therapy, the role of biologic agents for gastric cancer should also be explored in the adjuvant setting. With a deeper understanding of the molecular biology of gastric cancer, adjuvant therapy for patients with localized gastric cancer can be optimized and individualized.