Post-Treatment Surveillance to Detect Recurrent Disease in Esophagogastric Cancer: A Review of Current Practice and Future Perspectives.

Effective post-treatment surveillance in cancer is designed to drive early detection and treatment of recurrence; however, surveillance protocols following curative-intent treatment for esophagogastric adenocarcinoma (EGA) remain poorly defined, with no consensus across existing guidelines. Historically, a lack of evidence regarding optimal surveillance approaches has been underpinned by limited treatment efficacy in recurrent or metastatic disease. However, recent advances in chemotherapy, immunotherapy, and targeted approaches, as well as the management of oligometastatic disease, have transformed the therapeutic landscape, making early detection of recurrence increasingly actionable. The rising incidence of EGA in younger patients adds further urgency to understanding long-term surveillance and survivorship needs. While ongoing clinical trials seek to address this question, emerging technologies, including liquid biopsy, next-generation sequencing (NGS), and artificial intelligence (AI), promise to further advance surveillance strategies. This review explores the rationale for post-treatment surveillance in EGA and examines future technologies that will shape surveillance strategies into the future.