Predicting the risk of recurrent venous thromboembolism in patients with cancer: A prospective cohort study

The risk of recurrent venous thromboembolism (VTE) in cancer patients despite anticoagulant therapy is high. Clinical factors and pro-coagulant markers may identify high-risk patients and guide decisions about intensifying anticoagulation therapy. To evaluate whether serial measurements of pro-coagulant markers can identify patients at high risk of recurrent VTE. In this multicenter, prospective cohort study, patients with active cancer and acute deep vein thrombosis or pulmonary embolism were enrolled. Patients received standard low-molecular-weight heparin therapy and were followed for 6 months. D-dimer and soluble P-selectin levels were measured at baseline and 1, 4, 5, 12, and 24 weeks post treatment initiation. The association between recurrent VTE and a previously developed risk score, baseline values of the biomarkers, and individual relative changes from baseline were assessed. We enrolled 117 cancer patients (22% lung, 21% colorectal, 9% breast) with a mean age of 63 years; 62% had metastatic cancer. Eleven patients (9.4%) developed recurrent VTE, including two cases of fatal pulmonary embolism. VTE recurrence rates were 7.8% (95% CI, 3.1-18) in patients with a risk score of ≤0 points compared to 11% (95% CI, 5.2-20) for those with a score of ≥1 point (hazard ratio 1.3; 95% CI, 0.39-4.5). Baseline P-selectin levels but not D-dimer levels were significantly associated with a high risk of recurrence; the risk was four-fold higher in patients with elevated P-selectin levels than in those with normal levels (hazard ratio 4.0; 95% CI, 1.1-14). Changes in biomarker levels during treatment were not associated with recurrent VTE. Baseline P-selectin but not D-dimer levels predict recurrent VTE and may be a valuable addition to clinical prediction rules to select patients for more intensive therapy or closer observation