Tumor slice cultures enable rapid ex vivo profiling of patient-specific drug sensitivity in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is characterized by chemotherapy resistance, partly driven by its dense and heterogeneous tumor microenvironment (TME). Since most preclinical PDAC models inadequately capture the tissue architecture, their translational value for therapeutic testing remains limited. This study investigated organotypic tissue slice cultures (OTSCs), which preserve the multicellular tissue architecture, as a rapid platform for personalized ex vivo drug response profiling. OTSCs were generated from 27 resected PDAC specimens. Following workflow establishment and quality control, ex vivo drug profiling was performed in 15 patients using gemcitabine, gemcitabine plus paclitaxel, and FOLFIRINOX. Treatment response was assessed by quantitative digital pathology, and an ex vivo sensitivity score (EVSS) was defined. Clinical correlations with longitudinal follow-up were assessed in ten patients. OTSCs preserved tissue architecture and revealed interpatient heterogeneity. In exploratory analyses of clinically matched patients, ex vivo sensitivity was associated with prolonged PFS (median 445 vs. 141 days, log-rank p = 0.0027; HR per 10 EVSS points 0.625; 95% CI 0.484-0.807, p = 0.00032), while lower preoperative CA 19-9 levels and higher GATA6 expression were associated with higher EVSS and longer overall survival. OTSC-based profiling enables rapid, patient-specific drug response assessment in PDAC and supports evaluation as a functional stratification tool.