Abstract

Background

Several reports suggested that radiotherapy (RT) was related to an increased risk of cerebrovascular disease (CVD) in head and neck cancer patients, but other risk factors of CVD were not properly considered in estimating the risk of RT.

Method

To analyze the effect of RT on the risk of ischemic CVD in head and neck cancer patients, the Korean Central Cancer Registry data and Korean National Health Insurance Service data were used. A total of 5,570 patients with newly diagnosed head and neck cancer between the years 2003–2005 and without previously diagnosed CVD was included in our study cohort. The effect of treatment modality and other socioeconomic variables on ischemic CVD incidence were analyzed using the Cox proportional hazard regression model.

Results

The number of patients who received more than 20 fractions of RT for head and neck cancer (RT group) was 3,849 and 1,724 for those who did not receive RT (non-RT group). The total number of ischemic CVD events in the RT group was 302 (7.8%) and that in the non-RT group was 155 (9.0%). After adjustments for demographics, socioeconomic status, clinical risk factors of CVD, and treatment-related covariates, the adjusted hazard ratio for the RT group was 1.258 (95% confidence interval, 1.034–1.596; p=0.023).

Conclusion

The risk of ischemic CVD increased by RT after adjusting for other socioeconomic and clinical risk factors. Regular follow up and risk factor modifications for CVD should be recommended for head and neck cancer patients treated with RT.