Primary thromboprophylaxis in cancer outpatients – real-world evidence

Cancer-associated thrombosis (CAT) is a significant concern among patients with malignant diseases, leading to increased mortality. While current guidelines recommend primary thromboprophylaxis for venous thromboembolism (VTE) in medium-to-high-risk outpatients, this practice remains controversial. A better understanding of primary thromboprophylaxis is crucial, yet there is a lack of Real-World Evidence (RWE) in Portugal. This RWE study aimed to elucidate primary thromboprophylaxis practices among cancer outpatients in Portugal. A five-year observational multicentric study in eight Portuguese health institutions enrolled 124 adult cancer outpatients under primary thromboprophylaxis for VTE. The endpoints were CAT, bleeding, cancer progression and death. High thrombotic risk tumours were prevalent, with 57