Radiotherapy can increase the risk of ischemic cerebrovascular disease in head and neck cancer patients: A Korean population-based cohort study.

BACKGROUND AND PURPOSE:Several reports suggested that radiotherapy (RT) was related to an increased risk of cerebrovascular disease (CVD) in head and neck cancer (HNC) patients, but other risk factors of CVD were not properly considered in estimating the risk of RT. The purpose of this study is to analyze the effect of RT on the risk of CVD in HNC patients. MATERIALS AND METHODS:The Korean Central Cancer Registry data and Korean National Health Insurance Service data were used. A total of 5570 patients with newly diagnosed HNC between the years 2003-2005 was included in our study cohort. We analyzed the effect of treatment modality and other socioeconomic variables on ischemic CVD incidence using the Cox proportional hazard regression model both in the entire cohort (n = 5570) and in the propensity score matching (PSM) cohort (n = 3310). RESULTS:RT increased the CVD risk by 40.8% (aHR: 1.408, p = 0.006) in the entire cohort and by 44.3% (aHR: 1.443, p = 0.047) in the PSM cohort, respectively. CONCLUSION:The risk of ischemic CVD increased by RT after adjusting for other socioeconomic and clinical risk factors. Regular follow up and appropriate screening for CVD are required for HNC patients who received RT, and focus should be on advanced-age patients with a low socioeconomic status and known clinical risk factors of CVD.