Real-world incidence of cancer following a first unprovoked venous thrombosis: Results from the EPIGETBO study

Background: Venous thromboembolism (VTE) can be the first manifestation of cancer; however, the current incidence of malignancy in unselected patients with first unprovoked VTE needs to be confirmed. Material and methods: Between March 1st, 2013 and February 28th, 2015 we included and followed-up all patients living in the Brest district, France, who were seen in hospitals or the community for a first symptomatic unprovoked VTE event. The primary study outcome was the one-year incidence of cancer. Results: 526 patients, mean age 66.6 +/- 18.1 years, 246 (46.8%) men, were included in the study. In the year following VTE, 26 patients were diagnosed with cancer, corresponding to a one-year cumulative incidence of cancer of 5.06% (95% CI 3.47-7.35). Age >= 60, smoking and pulmonary embolism were significantly associated with cancer diagnosis in multivariate analysis. Fifty percent of cancers were patent at the time of VTE diagnosis, mostly detected on CTPA (Computed Tomographic Pulmonary Angiography) performed for pulmonary embolism assessment. After excluding patients with patent cancer at VTE diagnosis, the one-year incidence of cancer was 2.65% (95% CI: 1.55-4.52); in multivariate analysis, only current smoking was independently associated with a significant 5.4-fold increased risk for cancer diagnosis (HR 5.40; 95% CI 1.31-22.27). No cancer was diagnosed in patients aged 50 years or younger. Conclusion: The one-year incidence of cancer after a first unprovoked VTE was 5.06%. Half of the cancers were diagnosed during the diagnosis procedure for pulmonary embolism using CTPA.