# Novel CTC Detection Method in Patients with Pancreatic Cancer Using High-Resolution Image Scanning

## TL;DR

A new method for detecting circulating tumor cells in pancreatic cancer patients using high-resolution imaging could improve early diagnosis and treatment.

## Contribution

A novel CTC detection method combining negative enrichment and high-resolution image scanning is introduced for pancreatic cancer.

## Key findings

- The EpCAM assay achieved 76.3% CTC-positivity rate in pancreatic cancer patients with high sensitivity and specificity.
- High-resolution image scanning allows objective CTC detection by quantifying cell luminance values.
- The CSV assay did not show a valid threshold for distinguishing cancer patients from healthy controls.

## Abstract

Pancreatic ductal adenocarcinoma is one of the most lethal cancers, and its early diagnosis remains challenging. Circulating tumor cells, which are found in the bloodstream, have emerged as a promising marker for cancer diagnosis and treatment monitoring, but their detection rate in pancreatic ductal adenocarcinoma has been low. In this study, we developed a new detection method that combines negative enrichment with high-resolution image scanning. This approach allows an objective measurement of antigen expression and improves the accuracy of detecting circulating tumor cells. Our findings suggest that this method may provide a reliable and minimally invasive biomarker for the diagnosis of pancreatic ductal adenocarcinoma and has the potential to support earlier detection and better treatment strategies in the future.

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.