Characterization of Patient-Derived Esophageal Tumoroids for Long-Term Culture

Esophageal cancer, which includes esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), is a highly aggressive malignancy and ranks as the eleventh most prevalent cancer worldwide. Despite therapeutic progress, the 5-year survival rate remains poor. To enable the development of new treatment strategies, robust preclinical models of esophageal carcinoma are essential. Recent progress has enabled three-dimensional (3D) organoid systems generated from adult or pluripotent stem cells. Such organoids faithfully reproduce the architecture and functions of the tissue of origin and have been established from multiple human sources, including patient-derived tumors of the colon, prostate, breast, pancreas, esophagus, bladder, and liver. In this study, we generated three human esophageal cancer organoids from surgical specimens and maintained long-term cultures exceeding 12 months. All lines also met a practical durability benchmark—continuous growth for ≥3 months or ≥10 serial passages—thereby enabling consistent pharmacologic testing and cross-batch reproducibility. Two organoids originated from ESCC, and one from EAC that arose in Barrett’s esophagus. Whole-exome sequencing showed that these organoids preserved the genetic alterations present in the corresponding primary tumors. In parallel, patient-derived xenografts recapitulated the histopathology of the original esophageal cancers. Comprehensive assessments, including copy-number profiling and immunohistochemistry, demonstrated HER2 expression with amplification and HER3 expression with mutation in the EAC-derived organoid. Notably, HER2-directed antibody-drug conjugates (ADCs), including trastuzumab deruxtecan (T-DXd) and pertuzumab deruxtecan (P-DXd), effectively reduced tumor cell viability in these organoids. The successful creation of esophageal organoids with durable cultivability enables reproducible foundational studies, including drug-sensitivity testing, which are critical for advancing personalized therapy and rational treatment design. This work provides actionable resources for clinicians and researchers seeking to improve therapeutic approaches for esophageal cancer. Citation Format: Takashi Urano, Etsuko Yokota, Miki Iwai, Takuro Yukawa, Nagio Takigawa, Hideyo Fujiwara, Takashi Akiyama, Minoru Haisa, Takuya Fukazawa, Yoshio Naomoto, Tomoki Yamatsuji. Establishment and characterization of novel patient-derived esophageal tumoroids with long term cultivability [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 3415.