The Value of Blood T Cell Frequencies for Risk Prediction of Postoperative Complications in Pancreatic Cancer Surgery.

Objective: To quantify and characterize preoperative blood T cells in patients with pancreatic ductal adenocarcinoma (PDAC), who underwent tumor resection, and to determine their relevance as biomarkers for postoperative pancreas-specific complications.

Background: Pancreas-specific complications after pancreatic surgery are associated with a high morbidity and mortality, which both deprive patients of adjuvant chemotherapy. Noninvasive biomarkers for risk prediction of postoperative complications are missing, and the role of blood T cells for preoperative risk stratification is unknown.

Methods: The preoperative frequency of blood T cell subsets was analyzed for 73 patients with PDAC, who underwent proximal pancreatectomy. Patients were screened for postoperative complications such as pancreatic fistula, postpancreatectomy hemorrhage, and postpancreatectomy acute pancreatitis. The frequency of CD8⁺, conventional CD4⁺, and regulatory T cells, as well as the differentiation state of each T cell subset in the peripheral blood of patients with PDAC, was analyzed.

Results: Of 73 patients with PDAC, 19.2% developed pancreas-specific complications. The occurrence of postoperative complications was independent of the type of resection performed (Whipple procedure vs pylorus-preserving pancreaticoduodenectomy). Neither the frequency of CD8⁺, conventional CD4⁺, and regulatory T cells nor the state of T cell differentiation in the peripheral blood was associated with postoperative pancreas-specific complications. Notably, a significantly lower preoperative bilirubin serum level was observed in patients, who developed postpancreatectomy hemorrhage after proximal pancreatectomy (P =0.001).

Conclusions: A low preoperative bilirubin serum level was associated with a higher risk for postpancreatectomy hemorrhage after proximal pancreatectomy. However, the preoperative blood T cell frequency does not predict postoperative pancreas-specific complications.