Advances in occult cancer screening for patients with unprovoked venous thromboembolism: A narrative review of epidemiology, risk, and clinical strategies.

[BACKGROUND] Venous thromboembolism (VTE) and cancer exhibit a bidirectional correlation. The probability of detecting occult cancer in unprovoked VTE patients is significantly increased, and the cancer is often diagnosed at an advanced stage. Early screening is critical for improving prognosis; however, the effectiveness of current risk stratification and screening strategies remains controversial.

[METHODS] This review systematically integrated evidence on the epidemiology, risk stratification, and screening methods for occult malignancies in individuals with unprovoked VTE.

[RESULTS] Cancer-induced hypercoagulability and VTE-related inflammation interact bidirectionally, promoting thrombosis and cancer progression. In terms of risk stratification, elderly patients with VTE, as well as those comorbid with diabetes, diverticular disease, dementia, or with a history of aspirin use, have a higher detection rate of occult cancer. Occult cancer may also be indicated in patients with VTE at special sites, such as splanchnic vein thrombosis, cerebral venous thrombosis, and lower extremity arterial thrombosis, as well as in those with recurrent VTE. However, the impact of sex on the presence of occult cancer in VTE patients remains controversial. International guidelines recommend limited screening as a first-line approach, because extensive screening does not significantly improve prognosis. Positron emission tomography with computed tomography scan may enhance accurate cancer diagnosis. The Registro Informatizado Enfermedad TromboEmbólica (RIETE) and Screening for Occult Malignancy in Patients with Idiopathic Venous Thromboembolism (SOME) risk scores show limited predictive efficacy, while biomarkers and machine learning models demonstrate high diagnostic efficacy, indicating their potential application.

[CONCLUSIONS] Regular cancer screening is necessary for individuals with unprovoked VTE, and clinical practice should adopt individualized screening strategies based on risk stratification. Future research should focus on optimizing existing models and exploring the combined application of biomarkers and machine learning to improve cancer screening for this population.