D2 gastrectomy is now the globally accepted surgical standard for locally advanced gastric cancer. However, since 2000, different evidence has emerged regarding the efficacy of adjuvant chemoradiation, perioperative adjuvant chemotherapy, and postoperative chemotherapy for locally advanced gastric cancer. This review summarizes the background, current status, and future perspectives of adjuvant therapy for locally advanced gastric cancer. The Intergroup 0116 study was the first to show the significant overall survival benefits of adjuvant (chemoradiation) therapy for gastric cancer. The second study was the MAGIC trial, which showed the efficacy of perioperative adjuvant chemotherapy. Although the findings from the Intergroup 0116 study and the MAGIC trial were positive, recent studies, such as the ARTIST and EORTC 40954 studies, found no survival benefit for patients who had undergone D2 gastrectomy for gastric cancer. Regarding the adjuvant chemotherapy strategy, two pivotal phase III trials: the ACTS-GC and the CLASSIC, demonstrated the efficacy of postoperative adjuvant chemotherapy following D2 gastrectomy. However, more intensive chemotherapy is necessary to improve the survival rate. Several studies have analyzed the effectiveness of molecular-targeted therapy against metastatic gastric or gastroesophageal junction carcinoma. Further studies should focus on the survival benefit of more-intensive adjuvant therapy with D2 resection, or with concurrent molecular-targeted therapy.
Keywords: Adjuvant therapy; Chemotherapy; Gastric cancer; Radiation therapy; Surgery.