Establishment and identification of a patient-derived organoid model for esophagogastric junction adenocarcinoma

• Successfully established a patient-derived organoid model for esophagogastric junction adenocarcinoma with a primary culture success rate of 86.0% (43/50). • Organoids recapitulated key histological features of primary tumors, including atypical glandular architecture, high nuclear-to-cytoplasmic ratio, and mucin secretion. • Immunohistochemical analysis confirmed high concordance in Ki67, CEA, CK7, and Cadherin17 expression between organoids and primary tumors. • Tumor differentiation grade, neoadjuvant chemotherapy response, ex vivo time, and tumor mass significantly influenced organoid establishment success.