Abstract
Cancer immunotherapy, which harnesses the patient's own immune system to target malignant cells, has shown remarkable promise in reducing tumor burden and extending survival. However, the complex tumor microenvironment (TME) limits therapeutic benefits to a subset of patients, making it challenging to develop accurate in vitro models for drug response prediction, drug discovery, and personalized medicine. Organoids, three-dimensional (3D) "mini-organs" derived from individual patients that faithfully recapitulate the structural, molecular, and gene expression profiles of primary tumors along with their complex TME in vitro, have emerged as powerful tools for patient-specific drug screening and therapeutic strategy development. Their versatility has led to widespread adoption across both clinical and basic cancer research. However, a key limitation of traditional organoid models is their lack of immune system components. Recent years have seen significant efforts to address this challenge through the integration of immune cells with organoids, aiming to create more physiologically relevant models. This review describes 3D culture methods for immunocompetent organoids, explores organoid-immune cell interactions, and discusses their applications in cancer immunotherapy and drug screening, along with recent advances in related clinical studies.