Extracranial carotid artery disease in nasopharyngeal carcinoma patients with post-irradiation ischemic stroke

Abstract

Objective: Irradiation induced extracranial carotid occlusive disease has been recognized as a potential cause of post-irradiation stroke in nasopharyngeal carcinoma (NPC) patients. Our study aims to investigate the prevalence of extracranial CA disease in post-irradiated Taiwanese NPC ischemic stroke patients.

Methods: Forty-three NPC patients with ischemic stroke were retrospectively selected from the stroke registration of the study hospital and compared with 276 first-ever ischemic stroke patients from the same database, of which 31 patients underwent carotid duplex sonography (CDS). Significant atherosclerotic lesions of the carotid arteries were defined as a >50% stenosis or an occlusion according to CDS.

Results: Significant carotid lesions occurred in 13 of 31 (42%) NPC patients. Stroke was more frequently caused by large artery disease (44% versus 23%; p<0.01) in NPC patients than in first-ever stroke patients without NPC. Carotid artery disease (odds ratio 7.22, 95% confidence interval 2.51-20.77; p<0.0001) and absence of diabetes mellitus (odds ratio 0.26, 95% confidence interval 0.07-0.93; p=0.039) were the strongest independent discriminators between NPC stroke patients and non-NPC stroke patients in a multivariate logistic regression analysis.

Conclusion: Patients who received neck irradiation are at risk for the delayed development of diffused atherosclerosis but also for carotid occlusion within years, although the mechanism remains elusive and probably multifactorial.