The prognosis for pancreatic cancer (PC) is poor; however, the timely and accurate treatment of this disease will significantly improve prognosis. Serum biomarkers involve non-invasive tests that facilitate the early detection of tumors, predict outcomes and assess responses to therapy, so that the patient can be continuously monitored and receive the most appropriate therapy. Studies have reported that cancer antigen (CA)125 [also known as mucin 16 (MUC16)] has functional significance in the tumorigenic, metastatic and drug resistant properties of PC. Our aim was to use this biomarker in the diagnosis, detection of metastasis, prognosis and in the monitoring of the treatment effects of PC. Members of the Chinese Study Group for Pancreatic Cancer (CSPAC) reviewed the literature on CA125/MUC16 and developed an objective consensus on the clinical utility of CA125/MUC16 for PC. They confirmed the role of CA125/MUC16 in tumorigenesis and the progression of PC, and recommended monitoring CA125/MUC16 levels in all aspects of the diagnosis and treatment of PC, particularly those that involve the monitoring of treatments. In addition, they suggested that the combination of other biomarkers and imaging techniques, together with CA125/MUC16, would improve the accuracy of the clinical decision-making process, thereby facilitating the optimization of treatment strategies. Periodic clinical updates of the use of CA125/MUC16 have been established, which are important for further analyses and comparisons of clinical results from affiliates and countries, particularly as regards the in-depth biological function and clinical translational research of this biomarker.