Frequency of malignancy is high in patients admitted for a first venous thromboembolism episode: an observational study.

Patients with a cancer at time of first venous thromboembolism (VTE) have not been thoroughly analyzed. Our study aimed to (1) determine the frequency of cancer diagnosed in patients hospitalized for a first VTE episode, (2) investigate the characteristics of VTE and cancer in such patients. All consecutive adults patients hospitalized over a 6-years period for a first VTE episode in a tertiary care hospital were considered. Patients with congenital or acquired thrombophilia were excluded. Demographic, medical history, and follow up data were retrieved from medical records. 216 patients (63.6 ± 19.7 years, 63.4 % females) hospitalized for a first VTE were analyzed. Among them, 64 patients (29.6 %) had cancer, either revealed (n = 26) or already known (n = 38) at VTE diagnosis. Cancer was in an advanced stage in 26 patients (40.6 %). Patients with cancer were older and displayed a higher frequency of vena cava thrombosis, as compared to patients without cancer. VTE was more recurrent and mortality was higher in patients with cancer. Cancer occurred after VTE diagnosis in only 2 (2/127, 1.6 %) cases during a protracted follow-up of 24.1 ± 22.5 months. Overall, VTE preceded cancer diagnosis in only 3 % (2/66) of cases. Frequency of cancer is high among patients hospitalized for a first VTE. In such setting, VTE often involved unusual sites such as vena cava. In most cases, cancer was either already known or diagnosed at time of VTE, with a poor prognosis.