Simple SummaryAmong all types of pancreatic cancer, pancreatic ductal adenocarcinoma (PDAC) is the most common type and has an extremely low survival rate. Early detection at an early stage, when surgical removal is still available, is crucial to minimize the death toll of the individuals who are dying from PDAC. In this review, we have summarized the liquid biomarkers that are currently being used to diagnose PDAC in the clinic, clinical trials, and under development for potential use in the future. This review also provides insight into future liquid biomarkers that may be used in routine examinations for the early diagnosis of PDAC development and its precursors, hoping to significantly decrease PDAC death numbers.AbstractPancreatic ductal adenocarcinoma (PDAC), the most common type of pancreatic cancer, currently has a dismal five-year survival rate of approximately 10% due to late diagnosis and a lack of efficient treatment options such as surgery. Furthermore, the majority of PDAC patients have surgically unresectable cancer, meaning cancer cells have either reached the surrounding blood vessels or metastasized to other organs distant from the pancreas area, resulting in low survival rates as compared to other types of cancers. In contrast, the five-year survival rate of surgically resectable PDAC patients is currently 44%. The late diagnosis of PDAC is a result of little or no symptoms in its early stage of development and a lack of specific biomarkers that may be utilized in routine examinations in the clinic. Although healthcare professionals understand the importance of early detection of PDAC, the research on the subject has lagged and no significant changes in the death toll of PDAC patients has been observed. This review is focused on understanding potential biomarkers that may increase the early diagnosis of PDAC patients at its surgically resectable stage. Here, we summarize the currently available biomarkers used in the clinic as well as those being developed with the hope of providing insight into the future of liquid biomarkers to be used in routine examinations for the early diagnosis of PDAC.