Facts and figures in occult cancer screening among patients with unprovoked venous thromboembolism

Venous thromboembolism (VTE) may represent the first clinical manifestation of an underlying malignancy. Approximately 5-10% of patients presenting with an unprovoked VTE are diagnosed with cancer within the following year. This association has prompted interest in systematic cancer screening, although the optimal strategy remains debated due to potential harms, costs, and uncertain clinical benefit. Early studies suggested that extensive screening detects more cancers and may identify them earlier, but subsequent larger trials demonstrated no meaningful reduction in missed cancers, cancer-related mortality, or stage at diagnosis. An individual patient data meta-analysis including over 2,300 patients confirmed that extensive screening increases baseline cancer detection but does not improve 12-month cancer prevalence or survival and is associated with more false positives and downstream testing. Notably, age emerged as the strongest and most consistent predictor of occult cancer, whereas risk prediction scores such as RIETE and SOME showed limited discriminatory performance. Current international guidelines recommend a limited screening approach consisting of careful history and physical examination, basic laboratory tests, chest imaging when appropriate, and routine age- and sex-appropriate cancer screening. Ongoing research focuses on targeted screening in higher-risk patients and the evaluation of novel biomarkers.