Stroke Recurrence and Long-Term Mortality in Patients Diagnosed with Cancer Following Stroke

Purpose: Systemic cancer and ischemic stroke are major causes of mortality and share several risk factors, including older age, smoking, obesity, and inflammation.This study investigated the incidence of newly diagnosed cancers in stroke survivors and their outcomes. Materials and Methods:This retrospective observational study included patients with acute ischemic stroke enrolled between January 2010 and December 2019.We excluded patients with active or newly diagnosed cancer within 30 days of stroke onset.Primary outcomes were the incidence of new systemic cancer, recurrent ischemic stroke, and mortality.Results: A total of 5048 patients were included and followed for a median of 3.4 years (interquartile range 1.5-6.1 years).Among them, 242 (4.79%) were diagnosed with a new cancer, and 524 (10.4%) died during follow-up.At the time of cancer diagnosis, 48 patients (19.8%) had metastases.Factors associated with cancer occurrence included male sex [sub-distribution hazard ratio (SHR), 1.84; 95% confidence interval (CI), 1.27-2.67]and older age (SHR, 1.03; 95% CI, 1.01-1.04).During follow-up, 398 patients (7.9%) developed recurrent stroke, with a higher incidence in those with cancer than those without (14.9% vs. 7.5%, p<0.001).In multivariate Fine-Gray competing risk regression analyses, cancer was not significantly associated with recurrent stroke (SHR, 1.22; 95% CI, 0.77-1.91;p=0.395), but was significantly associated with increased mortality [hazard ratio, 2.57; 95% CI, 1.97-3.36;p<0.001].Conclusion: Cancer frequently developed in stroke survivors.Patients who developed cancer had a higher risk of mortality.Efforts for early cancer detection are warranted.