Correlation of Portal and Peripheral Venous ctDNA in Pancreatic Adenocarcinoma

Pancreatic adenocarcinoma is the 6th most common cancer in France and is expected to be the 2nd leading cause of cancer mortality in Europe by 2030. Its overall 5-year survival for all stages combined is estimated at 7-8%. Surgery is the only potentially curative treatment for pancreatic adenocarcinoma (PA), although only 10-20% of patients present with resectable disease. The oncological results of surgery alone are disappointing (median overall survival (OS) of 15-20 months and 5-year OS of 8-15%), due to the high frequency of recurrence. For this reason, surgery must be integrated into a comprehensive treatment sequence, also known as multimodal therapy. Significant progress has been observed over the past 5 years, with a marked increase in median OS in recent clinical trials, and an intensification of perioperative chemotherapy (CT) protocols. Liquid biopsy and circulating biomarkers show promise for improving the multidisciplinary approach to treatment of pancreatic adenocarcinoma. Circulating tumor DNA (ctDNA) is the most extensively studied marker in blood liquid biopsies and can provide insight into the molecular profile and individual characteristics of the tumor. This could pave the way for the identification of new therapeutic targets and markers of tumor response to complement diagnosis and provide improved stratified treatment. Similarly, the measurement of tcDNA in peritoneal fluid could provide a better understanding of individual tumour characteristics and the risk of peritoneal metastasis. It is important to assess whether portal venous ctDNA is likely to provide distinct information from peripheral venous ctDNA; if the two ctDNAs are highly correlated, then it seems unlikely that one can provide complementary information to the other. In addition, our work would evaluate the prognostic impact of the detection of circulating tumor DNA in portal venous blood collected intraoperatively, as well as its detection in peritoneal fluid.