Early stage gastric adenocarcinoma: clinical and molecular landscapes

Gastric adenocarcinoma, even when diagnosed at an early (localized) disease stage, poses a major health-care burden with cure rates that remain unsatisfactorily low, particularly in Western countries. This lack of progress reflects, among other aspects, the impracticality of early diagnosis, considerable variations in therapeutic approaches that is partly based on regional preferences, and the ingrained heterogeneity of gastric adenocarcinoma cells and their associated tumour microenvironment (TME). Clinical trials have long applied empirical interventions with the assumption that all early stage gastric adenocarcinomas are alike. Despite certain successes, the shortcomings of these approaches can potentially be overcome by targeting the specific molecular subsets of gastric adenocarcinomas identified by genomic and/or multi-omics analyses, including microsatellite instability-high, Epstein-Barr virus-induced, DNA damage repair-deficient, HER2-positive and PD-L1-high subtypes. Future approaches, including the availability of sophisticated vaccines, novel antibody technologies, agents targeting TME components (including fibroblasts, macrophages, cytokines or chemokines, and T cells) and novel immune checkpoint inhibitors, supported by improved tissue-based and blood-based diagnostic assays, seem promising. In this Review, we highlight current knowledge of the molecular and cellular biology of gastric adenocarcinomas, summarize the current approaches to clinical management of the disease, and consider the role of novel management and/or treatment strategies. Long-term survival rates of patients with gastric cancer remain low, particularly in Western countries. This lack of progress, among other aspects, is likely to reflect a focus on empirical approaches that fail to account for the heterogeneity of gastric cancers. In this Review, the authors summarize the available evidence on the management of patients with early stage gastric cancers, with an emphasis on understanding the underlying biology in order to improve the outcomes in patients with these historically difficult-to-treat tumours.

Automated summary

Gastric adenocarcinoma remains a challenging disease to diagnose and treat, with low cure rates, especially in Western countries. This is due to the impracticality of early diagnosis, regional variations in therapeutic approaches, and the heterogeneity of gastric cancer cells and their microenvironment. Targeted interventions based on molecular subsets of gastric adenocarcinomas identified by genomic and/or multi-omics analyses show promise for improved outcomes. Future strategies involving vaccines, novel antibody technologies, and agents targeting the tumor microenvironment and immune checkpoints, supported by improved diagnostic assays, hold potential for advancements in gastric cancer management.