Introduction: Although extensive screening in patients with venous thromboembolism (VTE) may result in early identification of hidden cancer, it is unknown whether the prognosis of these patients may be favorably influenced.
Patients and methods: RIETE is an ongoing, prospective registry of consecutive patients with objectively confirmed, symptomatic, acute VTE. We compared the 3-month outcome of patients with hidden cancer with that in patients in whom no symptoms of cancer were noted.
Results: Of 17,475 patients with acute VTE, 2852 (16%) had cancer diagnosed before VTE or during admission. Hidden cancer was detected in 178 (1.2%) of the remaining 14,623 patients. The most common sites were lung, prostate, colorectum, or hematologic, and 51% had metastases. As compared with patients in whom no symptoms of cancer were noted, those with hidden cancer had an increased incidence of recurrent VTE (11.4% vs. 2.1%; P < 0.001), major bleeding (5.1% vs. 2.1%; P = 0.007), and mortality (20% vs. 5.4%; P < 0.001). In the multivariate analysis, patients aged 60-75 years [odds ratio 1.8; 95% CI 1.2-2.7], with idiopathic VTE (odds ratio 3.0; 95% CI 2.2-4.2), with bilateral thrombosis (odds ratio 2.3; 95% CI 1.3-4.1) or with anemia (odds ratio 1.9; 95% CI 1.4-2.6) were at an increased risk for hidden cancer.
Conclusions: VTE patients with hidden cancer have an increased incidence of recurrences, major bleeding or death during the first 3 months of therapy. With four simple, easily obtainable variables, it is possible to identify a subgroup of VTE patients with a higher risk for hidden cancer.