Liquid Biopsy: A Highly Useful Tool to Decide Personalized Therapy in Veteran Patients with Metastatic Pancreaticobiliary Cancer

Abstract

Abstract Introduction/Objective Pancreatic cancer is one of the leading causes of death in Veteran patients. Early detection and treatment of the pancreatic cancers are key to the successful management of pancreatic cancer with good patient outcome. The National Comprehensive Cancer Network (NCCN) recommends tumor molecular profiling in all patient cases of unresectable or metastatic pancreatic adenocarcinomas and biliary tract cancers who are candidates for chemotherapy. This testing can be performed using liquid biopsy to obtain this molecular profiling from circulating tumor cells (CTC) to obtain information that may impact treatment. However, the literature of metastatic pancreaticobiliary cancers targeted by liquid biopsies and the mutations found is sparse, particularly for the veteran population. Methods/Case Report A retrospective review was performed of all patients with a submitted liquid biopsy specimen at a Veteran Affairs Medical Center (VAMC) from April 2020 to March 3rd, 2023, to examine those patients with metastatic pancreaticobiliary cancers, specifically pancreatic adenocarcinoma, and cholangiocarcinoma. Information on mutations detected was collected. Results (if a Case Study enter NA) There were a total of 5 patient specimens with a history of metastatic pancreatic adenocarcinoma (4 cases/5) and cholangiocarcinoma (1 case/5). The first liquid biopsy from a patient with a history of metastatic pancreaticobiliary cancer was sent on April 14th, 2020, and the last was sent on November 12th, 2021. TP53 was detected on all the successfully tested pancreatic adenocarcinoma cases. Other mutations detected in the individual pancreatic adenocarcinoma cases were KRAS, TET2 BCOR, DNMT3A, FUBP1, RAD21, and STAG2. The mutations found on the single cholangiocarcinoma case included DNMT3A and TP53. 1 of the 4 cases sent on a patient with pancreatic adenocarcinoma resulted in a sample failure. Conclusion Liquid biopsies provided comprehensive molecular profiling in cases of metastatic pancreatic adenocarcinoma and biliary tract cancer in the veteran population treated at a local VAMC to help decide on personalized therapy, in compliance with the recommendations of the NCCN. The results of this pilot quality assurance study help highlight the potential of liquid biopsies to detect most commonly mutated genes such as KRAS and T53 in pancreatic cancer.