Background: Unintentional weight loss is a common symptoms of pancreatic cancer, associating with systemic inflammation and affecting treatment, survival outcomes, and quality of life. The platelet to lymphocyte ratio(PLR) is a marker of systemic inflammation and was proven to be associVP-16半抑制浓度ated with poor outcomes in many cancer patients. The aim of this study is to determine the role of PLR in weight loss in patients with pancreatic cancer. Methods: This study retrospectively collected the data from electronic medical records of an academic hospital in Guangzhou. Patients newly diagnosed pancreatic cancer and hospitalized between 2019 and 2021 were included. Those who were bedbound on first admission, with terminal stage of cancer, or with less than twice readmission during the following 12-month period were excluded. Demographic(age, sex, current smoking statuPR-171使用方法s, regular drinking status), disease specific variables(TMN stage, treatment parameters), as well as dietary energy intake, weight and blood cells parameters during 12-month follow up period were assessed. Trajectory analyses were performed to identify distinct subgroups that share similar course of changes of weight. Results: A total of 136 patients with pancreatic cancer [aged Genetic circuits58.7±10.1years, 58.1% male] were included in this study. Participants have a median of 6(3-9) monthly records across a 7(4-12) months span. Based on records over the follow-up period, two weight trajectories were identified: stable pattern [weight loss, 3.3(0-6.6)%, n=79, 58.1%] and decreasing pattern [weight loss, 14.3(11.3-19.4)%, n=57, 41.9%]. The patients with decreasing weight pattern tended to be younger(aged 56.3±11.1 vs. 60.4±9.1years, p=0.020), with lower baseline lymphocyte counts [1.27(1.07-1.55) vs. 1.56(1.19-1.95), p=0.007] and higher baseline PLR [203(155-239) vs. 154(114-238), p=0.024]. Conclusion: An elevated PLR associated with greater weight loss in patients with pancreatic cancer. Based on these readily-available and routine biomarkers of systemic inflammation we may identify pancreatic cancer patients at risk for excessive weight loss.