Trimodality treatment in gastric and gastroesophageal junction cancers: Current approach and future perspectives

Gastric and gastroesophageal junction(GEJ) cancers represent an aggressive group of malignancies with poor prognosis even when diagnosed in relatively early stage, with an increasing incidence both in Asia and in Western countries.These cancers are characterized by heterogeneity as a result of different pathogenetic mechanisms as shown in recent molecular analyses. Accordingly,the understanding of phenotypic and genotypic correlations/classifications has been improved. Current therapeutic strategies have also advanced and moved beyond surgical extirpation alone, with the incorporation of other treatment modalities, such as radiation and chemotherapy(including biologics). Chemoradiotherapy has been used as postoperative treatment after suboptimal gastrectomy to ensure local disease control but also improvement in survival.Preoperative chemoradiotherapy/chemotherapy has been employed to increase the chance of a successful R0 resection and pathologic complete response rate,which is associated with improved long-term outcomes. Several studies have defined various chemotherapy regimens to accompany radiation(before and after surgery). Recently, addition of immunotherapy after trimodality of gastroesophageal cancer has produced an advantage in disease-free interval. Targeted agents used in the metastatic setting are being investigated in the early setting with mixed results. The aim of this review is to summarize the existing data on trimodality approaches for gastric and GEJ cancers, highlight the remaining questions and present the current research effort addressing them.