Neoadjuvant Treatment for Gastric Cancer

Abstract

Although complete surgical resection is the only curative treatment for gastric cancer, locoregional and distant recurrences are common after curative surgical resection, thus underscoring the importance of a multimodal treatment approach. Neoadjuvant treatment has the potential advantages of downsizing or downstaging, thus increasing the rates of curative R0 resection, early systemic micrometastasis control, and better treatment tolerance than adjuvant therapy. Neoadjuvant therapy has mainly been pursued in Western countries where locally advanced disease and gastroesophageal junction or proximal gastric cancer are common, curative resection rates are relatively low, and surgical outcomes remain suboptimal. Two randomized phase III studies in Western countries (MAGIC and FNCLCC/FFCD 9703) demonstrated survival benefits of perioperative chemotherapy (pre- and postoperative) over surgery alone for resectable gastric, gastroesophageal junction, or distal esophageal adenocarcinoma. Accordingly, perioperative chemotherapy has been established as a standard therapy for resectable gastric cancer in Western countries. A current ongoing clinical trial (PRODIGY) is evaluating the role of perioperative chemotherapy in East Asian populations with D2 lymphadenectomy. Regarding pathologic complete response, neoadjuvant chemoradiotherapy provides a clear advantage over chemotherapy alone. The impact of neoadjuvant chemoradiotherapy on long-term survival in resectable gastric cancer is under investigation in several phase III studies. These study results will help us further refine neoadjuvant treatment within multidisciplinary strategies for localized gastric cancer.