Occult cancer and thromboembolism: current epidemiology and its practical implications.

Venous thromboembolism (VTE) may be the first presentation of malignancy. Up to 10% of patients with unprovoked VTE are diagnosed with occult cancer within 1 year. Cancer patients with concomitant VTE have a worse outcome. While limited screening strategy (thorough medical history, physical examination, basic laboratory tests, and chest X‑ray) and extensive screening strategy (limited screening plus computed tomography scan of the abdomen/pelvis or 18F-fluorodeoxyglucose positron emission tomography-computed tomography) have a similar ability to detect early-stage cancer and improve morbidity and mortality of cancer patients with unprovoked VTE, the extensive screening strategy has been shown to diagnose occult cancer earlier. Among the risk factors for occult cancer in patients with unprovoked VTE, age is the most promising one. The risk of occult cancer detection increases with age. The newly developed RIETE score helps identify risk of occult cancer and might decrease unnecessary diagnostic procedures in lower-risk patients. Current guidelines suggest that patients with first unprovoked VTE undergo limited screening, with age- and sex-specific cancer screening, including colon, breast, cervical, and prostate cancers.