Discovery of New Cancer in the 1-year Follow-up After Ischemic Stroke in Patients at Risk: The INVISIBLE-1 Study

This study — called INVISIBLE-1 — is following people who had a stroke of unknown cause (called an embolic stroke of undetermined source, or ESUS) to check whether they may have an undetected cancer in the year after the stroke. Researchers believe some unexplained strokes may be an early sign of hidden cancer. **You may be eligible if...** - You are 18 years or older - You have had an acute ischemic stroke (a stroke caused by a blocked blood vessel) with symptoms starting within 48 hours before coming to the hospital - After initial workup, the cause of the stroke remains unknown (ESUS — no detected atrial fibrillation, large vessel blockage, or other obvious cause) - A blood test taken shortly after your stroke showed an elevated D-dimer level (a clotting marker often elevated with cancer) **You may NOT be eligible if...** - You already have a known active cancer diagnosis - You were given clot-busting treatment (thrombolysis) before the D-dimer blood test was taken - You have been newly diagnosed with a brain cancer - You or your family are unlikely to be able to complete follow-up Talk to your doctor to see if this trial is right for you.