Elevated risk of ischemic stroke after invasive cancer diagnosis: A nationwide population‐based study
Abstract Background Cancer and stroke are major causes of morbidity and mortality, with an increasing shared burden. This study aimed to provide population‐based estimates of ischemic stroke (IS) risk after cancer diagnosis across multiple cancer sites and demographic subgroups. Methods A retrospective cohort study was conducted linking the Israel National Cancer and Stroke Registries. Residents ≥40 years old diagnosed with first invasive cancer during 2014–2021 were followed for first‐ever IS within 1 year. IS risk was assessed using standardized incidence ratios (SIRs) and analyzed by cancer site, time since diagnosis, cancer stage, and demographic subgroups. One‐year cumulative incidence was estimated with death as a competing event. Results Among 182,221 patients, the SIR for IS within 1 year after cancer diagnosis was 1.8 (95% confidence interval [CI], 1.7–1.9). Risk peaked during the first 3 months (SIR, 2.5; 95% CI, 2.2–2.7). The highest SIRs were observed for pancreatic (SIR, 5.9; 95% CI, 4.8–7.3) and lung (SIR, 3.9; 95% CI, 3.4–4.4) cancers. SIRs decreased with age from 3.6 (95% CI, 2.8–4.6) among adults 40–54 years old to 1.4 (95% CI, 1.3–1.6) among those ≥75 years old. SIRs increased with stage, from 1.2 (95% CI, 1.0–1.4) in localized disease to 2.8 (95% CI, 2.5–3.2) in metastatic disease. One‐year cumulative incidence of IS was 0.62%, ranging from 0.30% in breast cancer to 1.62% in pancreatic cancer. Conclusions The early period after cancer diagnosis represents a critical window of increased IS risk. Incorporating targeted cerebrovascular risk assessment into oncologic care may facilitate earlier identification of high‐risk subgroups and support tailored prevention strategies.