P-278 Survival impact and predictive scores for thrombosis associated with pancreatic ductal adenocarcinoma (PDAC)

Venous thromboembolism (VTE) is the second most prevalent cause of cancer mortality. PDAC is associated with a high thrombotic risk, with reported incidences up to 40%. Khorana and Onkotev scores predict the risk of thrombosis in cancer patients. This retrospective, observational study included patients with PDAC treated with chemotherapy and visited in the Medical Oncology Department of Hospital de la Santa Creu i Sant Pau between January 2014 and December 2021. The main objectives were to describe the frequency of VTE and to discriminate the ability to predict VTE risk by two known scores (Khorana and Onkotev) using ROC curve. Secondary endpoint was to analyze overall survival (OS) associated with VTE. A total of 204 patients were included with a median follow-up of 11 months. The median age of patients at diagnosis was 70.5 years (range 56.5 - 84.5), 56.8% were male and 45.1% presented stage IV at the time of diagnosis. The incidence of VTE was 30.4% and according to the stage: 42.9% in metastatic and unresectable disease, 30% in borderline and 8.2% in localized tumors, being 50% tumor thrombosis. In 8 cases (12.9%) the VTE occurred three months prior cancer diagnosis and two patients were already on anticoagulant therapy. The 67.7% of VTE events affected the venous system of the digestive tract (p < 0.01) and 8% were pulmonary embolisms. The Onkotev score showed better capacity to predict VTE than Khorana score (AUC 0.727 vs. AUC 0.570). OS in patients who presented VTE was 13.9 months vs. 23.1 months for those who did not present a thromboembolic event (HR 0.71, p 0.034). In our cohort, VTE was detrimental to survival. It is a common complication in patients with pancreatic cancer that is related with tumor stage. The Onkotev score has greater capacity to predict VTE risk than Khorana score, helping us to identify potential patients who could benefit from primary anticoagulation.