The influence of circulating lymphocyte changes and tumor microenvironment factors on survival prognosis of patients with pancreatic ductal carcinoma

This work aims to evaluate the initial values and changes of peripheral blood lymphocytes during treatment, as well as the influence of the relationship with tumor microenvironment factors on the overall survival of patients with pancreatic cancer. Pancreatic ductal adenocarcinoma (pancreatic cancer) is an oncological disease that determines the poor prognosis of patients due to the unique anatomy of the organ, the absence of preventive screening programs, various tumor barriers, and the sluggishness of the immune system, little choice of medical treatment, and the lack of predictive biomarkers. In this work, we investigated the number of lymphocyte subpopulations circulating in the peripheral blood as an essential immune system biomarker, by flow cytometry, in patients before and after surgery and during chemotherapy treatment. This dissertation focuses on the influence of pretreatment circulating lymphocytes on survival outcomes. In addition, we found that tumor-stroma ratio may influence progression-free survival. Summarizing all the results, we believe that in the resectable group, a lower initial value of T regulatory CD8+CD25+CD127+/– is associated with better overall survival; a low tumor-stroma ratio is associated with better progression-free survival, and in the advanced and metastatic disease (unresectable) group, a higher baseline CD8+CD57- cell value is associated with better progression-free survival and overall survival