Clinical significance of non-invasive in vitro drug sensitivity profiling using pancreatic cancer organoids derived from saline flushes collected during routine EUS-FNA

Purpose To evaluate the in vitro drug sensitivity of patient-derived cancer organoids (PDCOs) established from residual samples from saline flushes (RSSF) collected during routine endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in patients with pancreatic cancer. Methods Organoids were cultured under mutation-selective conditions. IC 50 values for 5-fluorouracil (5-FU), SN-38, oxaliplatin, gemcitabine, and paclitaxel were calculated. Results PDCOs showed variable responses to the drugs. Exploratory quantitative analysis using ordinal sensitivity scoring and ROC curves (Area under the curve [AUC] up to 0.917) indicated that lower in vitro IC₅₀ scores tended to associate with clinical responders (PR/uPR) compared with non-responders (progressive or stable disease [PD/SD]). Conclusions This study demonstrated the feasibility and potential usefulness of in vitro drug sensitivity profiling of pancreatic cancer using RSSF-derived PDCOs. These findings represent the first step toward clinical application, and further validation in larger cohorts is warranted.