Acute Ischemic Stroke in Patients With Active Cancer

The goal of this multicenter prospective observational study, conducted at 24 hospitals in Japan, is to learn about recurrent ischemic stroke in people with active cancer who develop acute ischemic stroke. One of the main objectives is to evaluate how often ischemic stroke recurs during follow-up. The main questions this study aims to answer are: * How often does ischemic stroke recur within 3 months after the initial stroke? * Which clinical factors may be associated with recurrent ischemic stroke? * What other clinical outcomes occur during follow-up? Participants will receive medical care determined by their treating physicians. Researchers will collect information about participants' cancer, stroke characteristics, test results, treatments, recurrent ischemic stroke, and other clinical outcomes. Researchers will also explore whether clinical factors are associated with recurrent ischemic stroke and other outcomes. This study will not assign participants to a specific treatment.