Abstract Introduction: Gastric cancer (GC) is a major health problem in Chile, with high incidence and mortality rates, particularly among younger populations. Diffuse GC is the most aggressive subtype, characterized by a poorly cohesive and signet-ring cell features, matching the genomically stable molecular subtype. These tumors are frequently linked to advanced nodal metastasis and peritoneal dissemination. Response to chemotherapy is generally limited, although a subset of GC patients can achieve significant clinical efficacy from first-line immunotherapy (PD-1/PDL-1 inhibitors plus chemotherapy). Patient-derived organoids (PDOs), three-dimensional cultured generated from stem cells, can recapitulate tumor heterogeneity and have emerged as a powerful preclinical model for studying tumor biology and predicting response to anticancer treatments. The aim of this study was to characterize GC PDOs and evaluate their responses to drug treatment. Material and Methods: Fresh tumor tissues and ascites samples obtained from GC patients were enzymatically dissociated using collagenase/dispase solution and cultured following a modified protocol previously described. PDOs and their corresponding original tissues were characterized using H Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 735.
Bizama et al. (2026) studied this question.