Modeling of Patient-Derived 3D Organoids of Thyroid Cancer: From Cells to Care.

Introduction: Three-dimensional (3D) organoids derived from patient tissues have emerged as promising preclinical models that preserve tumor architecture and phenotypic heterogeneity better than conventional two-dimensional cultures. This study aimed to establish patient-derived 3D organoid models for anaplastic thyroid carcinoma (ATC) and clinically radioiodine-refractory papillary thyroid carcinoma (RAIR-PTC) and evaluate whether they retained the histopathologic and immunophenotypic features of their source tumors. Methods: Tumor tissues from patients with ATC and RAIR-PTC were collected, dissociated, and embedded in Matrigel for 3D culture. Organoid growth was monitored during serial passaging. Histopathologic, immunophenotypic, and targeted molecular analyses were performed. Results: The TCO001 sample, derived from ATC, showed substantial growth for more than five months, up to Passage 11, whereas the TCO002 sample, derived from RAIR-PTC, exhibited limited proliferation and could not be maintained beyond Passage 3 after four months. These differences in culture performance were further supported by Ki-67 and p53 staining, which demonstrated markedly higher proliferative activity and a more aberrant p53 expression pattern in TCO001 than in TCO002. Histopathologic and immunophenotypic analyses showed a dedifferentiated, ATC-like phenotype in TCO001 and a more differentiated thyroid carcinoma-like phenotype in TCO002. Targeted molecular analysis further supported the biological differences between the two lines: TCO001 harbored a BRAF mutation and a TERT promoter alteration, whereas TCO002 was wild type for both genes, consistent with the matched primary tumor tissue. Discussion: This study provides preliminary proof of concept that patient-derived organoid technology can be extended to aggressive thyroid cancer phenotypes and preserve subtype-relevant differences in differentiation state. Although preliminary, these findings support the value of thyroid cancer organoids as patient-relevant preclinical models and provide a basis for future molecular, functional, and therapeutic studies in aggressive thyroid cancer.