Cellular Components Contributing to the Development of Venous Thrombosis in Patients with Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive type of cancer and has a poor prognosis. Patients with PDAC are at high risk of developing thromboembolic events, which is a leading cause of morbidity and mortality following cancer progression. Plasma-derived coagulation is the most studied process in cancer-associated thrombosis. Other blood components, such as platelets, red blood cells, and white blood cells, have been gaining less attention. This narrative review addresses the literature on the role of cellular components in the development of venous thromboembolism (VTE) in patients with PDAC. Blood cells seem to play an important role in the development of VTE. Altered blood cell counts, i.e., leukocytosis, thrombocytosis, and anemia, have been found to associate with VTE risk. Tumor-related activation of leukocytes leads to the release of tissue factor-expressing microvesicles and the formation of neutrophil extracellular traps, initiating coagulation and forming a scaffold for thrombi. Tissue factor-expressing microvesicles are also thought to be released by PDAC cells. PDAC cells have been shown to stimulate platelet activation and aggregation, proposedly via the secretion of podoplanin and mucins. Hypofibrinolysis, partially explained by increased plasminogen activator inhibitor-1 activity, is observed in PDAC. In short, PDAC-associated hypercoagulability is a complex and multifactorial process. A better understanding of cellular contributions to hypercoagulability might lead to the improvement of diagnostic tests to identify PDAC patients at highest risk of VTE.

Altered whole blood thrombin generation and hyperresponsive platelets in patients with pancreatic cancer

BACKGROUND

Thromboembolic disease is a major complication in patients with pancreatic ductal adenocarcinoma (PDAC). Patients with PDAC often have altered blood cell counts, which are associated with venous thromboembolism (VTE) development. The high thrombotic risk in patients with PDAC may be partially caused by procoagulant blood cells.

OBJECTIVES

The aim of this study was to compare blood cell-dependent coagulation between patients with PDAC (n = 18) and healthy controls matched for age and sex (n = 18).

METHODS

Thrombin generation (TG) was measured in whole blood (WB) and plasma. The capacity of platelets to release granules (PGRCs) was measured in WB. We explored the occurrence of thromboembolic events in patients with PDAC during a 6-month follow-up.

RESULTS

Patients showed an increased endogenous thrombin potential in WB compared with controls. This difference was not observed in plasma, indicating a procoagulant effect of blood cells. Both in WB and plasma, the lag time was prolonged in patients compared with controls. Patients had hyperresponsive platelets, with a shorter time to peak granule release. Of the 18 patients with PDAC, 4 developed a venous thromboembolism (22%) and 1 developed an arterial thrombosis (6%). A shorter lag time in WB, but not in plasma, and an increased PGRC were associated with thromboembolic events.

CONCLUSION

Patients with PDAC have an increased and delayed WB TG coagulation profile compared with controls. A shorter lag time in WB TG and increased PGRC are associated with the incidence of thromboembolic events. Platelets appear to be key players in thrombosis development. Measuring hemostasis in WB could improve thrombosis risk estimation in patients with PDAC.

Venous Thromboembolism and Primary Thromboprophylaxis in Perioperative Pancreatic Cancer Care

Recent studies have shown that patients with pancreatic ductal adenocarcinoma (PDAC) treated with neoadjuvant chemo(radio)therapy followed by surgery have an improved outcome compared to patients treated with upfront surgery. Hence, patients with PDAC are more and more frequently treated with chemotherapy in the neoadjuvant setting. PDAC patients are at a high risk of developing venous thromboembolism (VTE), which is associated with decreased survival rates. As patients with PDAC were historically offered immediate surgical resection, data on VTE incidence and associated preoperative risk factors are scarce. Current guidelines recommend primary prophylactic anticoagulation in selected groups of patients with advanced PDAC. However, recommendations for patients with (borderline) resectable PDAC treated with chemotherapy in the neoadjuvant setting are lacking. Nevertheless, the prevention of complications is crucial to maintain the best possible condition for surgery. This narrative review summarizes current literature on VTE incidence, associated risk factors, risk assessment tools, and primary thromboprophylaxis in PDAC patients treated with neoadjuvant chemo(radio)therapy.