Previous Ischemic Stroke Significantly Alters Stroke Risk in Newly Diagnosed Cancer Patients.

Area of Science:

• Oncology
• Neurology
• Cardiovascular Medicine

Background:

• Previous ischemic stroke (IS) is a known risk factor for subsequent IS in the general population.
• The relationship between prior IS and future IS risk in cancer patients remains unclear.

Purpose of the Study:

• To examine the association between a history of ischemic stroke (IS) and the risk of subsequent IS in individuals newly diagnosed with cancer.

Main Methods:

• Retrospective, population-based, matched cohort study in Ontario, Canada (2010-2020).
• Matched 13,070 cancer patients with prior IS to 52,455 cancer patients without prior IS.
• Used cumulative incidence functions and subdistribution adjusted hazard ratios (aHRs), treating death as a competing event.

Main Results:

• Individuals with prior IS had a significantly increased risk of IS after cancer diagnosis (aHR, 2.68).
• The highest stroke risk was observed in gynecologic (aHR, 3.84) and lung cancer (aHR, 3.18) subgroups.
• Stroke risk was inversely correlated with lag time; IS within 1 year before cancer diagnosis showed the highest risk (aHR, 3.68).

Conclusions:

• A history of ischemic stroke (IS) nearly triples the risk of experiencing a subsequent stroke after a new cancer diagnosis.
• The risk is particularly elevated if the prediagnosis stroke occurred within the year preceding the cancer diagnosis.