Revisiting the Immunological Landscape of Locoregional Therapies for Gastrointestinal Cancers: A Shift Toward Interventional Immuno-Oncology.

PURPOSE OF REVIEW: Locoregional therapies have emerged as key components in the therapeutic arsenal against gastrointestinal cancers, offering minimally invasive options with curative potential. Beyond their direct cytotoxic effects, these interventions can remodel the tumour microenvironment by inducing immunogenic cell death and initiating local and systemic immune responses, including abscopal effects. This review aims to examine how these immunomodulatory properties may support locoregional therapies as an ideal platform for intratumoural immunotherapy, positioning their combination at the core of the evolving field of interventional immuno-oncology.

RECENT FINDINGS: Recent studies demonstrate that locoregional therapies can induce immune responses through modulation of the tumour microenvironment, creating conditions that may be exploited by intratumoural immunotherapy. This review provides a comprehensive overview of current locoregional modalities, including thermal and non-thermal ablative techniques, transarterial therapies, and minimally invasive radiation methods, detailing their mechanisms of action, clinical applications, and immune-related effects. Special attention is given to emerging evidence supporting the combination of these approaches with intratumoural delivery of immunomodulatory agents, to enhance anticancer immune responses. The convergence of locoregional intervention and targeted immunomodulation represents an emerging therapeutic concept in the treatment of gastrointestinal cancers, offering the prospect of personalised, tumour-directed immune activation. This approach holds the potential to extend the benefits of immunotherapy beyond genetically defined subgroups to a broader patient population.