Tatsuhiro Araki

Background/Objectives: Appropriate biomarkers are necessary for early diagnosis and multidisciplinary treatment of pancreatic ductal adenocarcinoma (PDAC). In recent years, the clinical utility of circulating tumor cells (CTC) as biomarkers for various can-cers has been reported; however, their detection rate in PDAC remains low, and clinical evidence is not yet established. CTC detection methods with high reliability and per-formance are essential for clarifying the importance of CTC in patients with PDAC. Methods: A total of 5 mL peripheral blood samples were collected from 38 patients newly diagnosed with PDAC and 17 healthy controls. Negatively enriched cells were immunofluorescently stained with EpCAM-phycoerythrin and cell surface vi-mentin-fluorescein isothiocyanate (CSV). Images were automatically captured using an all-in-one fluorescence microscope. Cellular regions were detected from these images, and the average luminance of the cellular regions was calculated. A total of 9086 and 1071 cell images were obtained from patients with PDAC and healthy controls, respec-tively. Results: In the EpCAM assay, a threshold that included 95% of healthy individuals was optimal for distinguishing patients with PDAC from healthy controls, with a sensi-tivity, specificity, and area under the curve of 0.74, 0.76, and 0.84, respectively. At this threshold, the CTC-positivity rate in patients with PDAC was 76.3%. Conversely, the CSV assay failed to demonstrate a valid threshold to distinguish patients with PDAC from healthy controls. No significant differences were found between CTC and clini-copathological features among patients with PDAC. Conclusions: The method using high-resolution image scanning has the potential to identify CTC with greater objectiv-ity by quantifying cell luminance values.

Background/Objectives: Appropriate biomarkers are necessary for early diagnosis and multidisciplinary treatment of pancreatic ductal adenocarcinoma (PDAC). In recent years, the effectiveness of circulating tumor cells (CTCs) as biomarkers for various cancers has been reported; however, their detection rate in PDAC remains low, and sufficient evidence are not yet established. CTC detection methods with high reliability and performance are essential for clarifying the importance of CTCs in patients with PDAC. Methods: A total of 5 mL peripheral blood samples were collected from 38 patients newly diagnosed with PDAC and 17 healthy controls. Negative enriched cells were immunoflu-orescently stained with EpCAM-phycoerythrin and cell surface vimentin-fluorescein isothiocyanate(CSV). Images were automatically captured using an all-in-one fluorescence microscope. Cellular regions were detected from the captured images and the average lu-minance of the cellular regions was calculated. A total of 9086 and 1071 cell images were obtained from patients with PDAC and healthy controls, respectively. Results: In the Ep-CAM assay, a threshold that included 95% of healthy individuals was optimal for distin-guishing patients with PDAC from healthy controls, with a sensitivity, specificity, and AUC of 0.74, 0.76, and 0.84, respectively. At this threshold, the CTC-positivity rate in pa-tients with PDAC was 76.3%. Conversely, the CSV assay failed to demonstrate a valid threshold to distinguish patients with PDAC from healthy controls. No significant differ-ences were found between CTC and clinicopathological features among patients with PDAC. Conclusions: This method using high resolution image scanning has the potential to identify CTCs with greater objectivity by quantifying cell luminance values.