Cancer-associated thrombosis in patients with implanted ports: a prospective multicenter French cohort study (ONCOCIP).

The need to accurately identify cancer outpatients at high risk of thrombotic complications is still unmet. In a prospective, multicenter cohort study (ONCOlogie et Chambres ImPlantables [ONCOCIP]), consecutive adult patients with a solid tumor and implanted port underwent 12-month follow-up. Our primary objective was to identify risk factors for (1) catheter-related thrombosis, defined as ipsilateral symptomatic upper-limb deep-vein thrombosis with or without pulmonary embolism, and (2) venous thromboembolism other than catheter-related, defined as any symptomatic superficial- or deep-vein thrombosis (other than catheter-related) or pulmonary embolism, and incidental pulmonary embolism. All events were objectively confirmed and centrally adjudicated. Rate assessments integrated competing risk of death. Overall, 3032 patients were included (median age: 63 years; women: 58%). The most frequent cancer locations were breast (33.7%), lung (18.5%), and colorectal (15.6%), cancer being metastatic in 43.2% of patients. Most patients (97.1%) received chemotherapy. By 12 months, 48 (1.6%) patients had been lost to follow-up and 656 (24.6%) had died; 3.8% (n = 111) of patients had experienced catheter-related thrombosis, and 9.6% (n = 276) venous thromboembolism other than catheter-related. By multivariate analysis, use of cephalic vein for catheter insertion predicted catheter-related thrombosis, whereas ongoing antiplatelet therapy was protective; risk factors for venous thromboembolism other than catheter-related were advanced age, previous venous thromboembolism, cancer site, and low hemoglobin level or increased leukocyte count before chemotherapy. In conclusion, this large prospective cohort study showed a high rate of venous thromboembolism in patients with a solid tumor and implanted port. Risk factors for catheter-related thrombosis differed from those for venous thromboembolism not catheter-related. This trial was registered at www.clinicaltrials.gov as #NCT02025894.