The origin of patient-derived cancer organoids from pathologically undiagnosed specimen in patients with pancreatobiliary cancers.

Purpose: Tissue confirmation of pancreatobiliary cancer is often difficult because of the location of the tumor and structure of the surrounding blood vessels. Patient-derived cancer organoids (PDCOs) reflect the genomic characteristics of individual cancers. Although diverse attempts to construct PDCOs for various pancreatobiliary cancer models are ongoing, no research results have yet confirmed the possibility of performing a precise diagnosis on PDCOs derived from pathologically negative patient samples.

Methods: We obtained a total of nine samples, including pathologically negative samples, from four patients (three patients with pancreatic cancer and one patient with gallbladder cancer) using different tissue acquisition methods to establish PDCOs (success rate 75%).

Results: We successfully verified whether the constructed PDCOs could represent the tissues of patients with pancreatobiliary cancer at each multi-omics level using tumor panel sequencing, single-cell RNA sequencing, hematoxylin and eosin, and immunohistochemical staining. PDCOs from pathologically negative samples showed expression patterns of malignant ductal cell-related biomarkers similar to those of other pathologically positive samples. Furthermore, the expression patterns at the single-cell level in PDCO from patients ultimately diagnosed with gallbladder cancer after surgery were different from those in patients with pancreatic cancer.

Conclusion: Therefore, our study implicated the potential of PDCOs as diagnostic and research tools, including for case involving limited tissue samples. Based on these results, we anticipate that this could be extended to more advanced studies, such as drug sensitivity testing, through large-scale trials in the near future.