Background: Several studies have indicated an association between venous thromboembolism (VTE) and a subsequent diagnosis of cancer in Western countries. However, information is scant on subsequent cancer incidence after idiopathic VTE events in Asian people. Through a nationwide cohort study, we evaluated the cancer prevalence of VTE and new cancer incidence in patients after the first episode of idiopathic VTE.
Methods: To conduct a nationwide population cohort study on VTE, we retrieved data from the Taiwan National Health Insurance Database from 1998 to 2008, including a 2-year follow-up period extending to the end of 2010. The occurrence of cancer in the cohort was also determined by accessing the Registry for Catastrophic Illness Patient Database.
Results: A total of 45 242 patients had the newly diagnosed VTE from 1998 to 2008. The incidence of VTE increased with age. Among 28 243 idiopathic VTE patients, 1944 patients (6.89%) had a subsequent cancer diagnosis within 2 years of the first idiopathic VTE episode. The three most common newly diagnosed cancers after idiopathic VTE were lung cancer, liver cancer and colorectal cancer (18.3%, 12.3% and 10.9%, respectively). Male sex and advanced age are independent risk factors of having an underlying malignant disorder among patients diagnosed with idiopathic VTE.
Conclusion: Patients with symptomatic VTE without an identifiable risk factor have a 6.89% incidence of subsequent cancer diagnosis in Taiwan. An extensive screening for an occult cancer in an idiopathic VTE patient may be warranted.