Occult Cancer

This study aims to externally validate the CLOVER score, a machine learning-based predictive model designed to identify patients with venous thromboembolism (VTE) who are at increased risk of having an occult cancer. The study includes a retrospective cohort of patients with acute symptomatic VTE diagnosed between 2000 and 2022, and a prospective cohort of consecutively recruited patients from December 2025 to December 2027. The CLOVER model will be applied to all participants, and its ability to discriminate between patients with and without occult cancer will be evaluated. The study also assesses clinicians' satisfaction with the web-based tool (CLOVER-Web) developed to facilitate the use of the score in clinical practice.

The INCOGNITO Pilot Trial is a single centre pilot prospective randomized open-label blinded endpoint (PROBE) trial to assess the feasibility of a full-scale randomized trial to determine whether an occult cancer screening strategy of FDG PET/CT (F-fluorodeoxyglucose positron emission/computed tomography) in addition to usual care increases the number of occult cancers diagnosed after screening compared to usual care cancer screening alone in patients with cryptogenic stroke.

INVISIBLE-1 aims to prospectively follow patients up to one year after ischemic stroke to: 1. Determine the cumulative incidence of occult cancer in patients with embolic stroke of undetermined source (ESUS) and elevated D-dimer 2. Describe occult cancer characteristics and spontaneous course of occult cancer Methodology The investigators will include 370 stroke patients with elevated D-dimer (≥ 820 μg/L) at the time of stroke, suspicion of ESUS after initial workup and without known cancer. The investigators will perform a follow-up telephone interview at one year to assess the occurrence of a new cancer and characterize the course of the disease. Significance Determining the real incidence of occult cancer in high-risk patients will help support the implementation of screening trials in the future. Faster detection and treatment of occult cancers would significantly impact patient' outcomes by offering faster cancer treatment and optimal secondary stroke prevention.