Risk of cardiovascular-related death after radiotherapy for thoracic cancer

Cardiotoxicity following thoracic radiotherapy remains a critical issue, and this study aimed to assess the risk of Cardiovascular-Related Death (CVRD) after thoracic radiotherapy while comparing the risk of CVRD at different cancer sites. Data on patients with thoracic cancers treated with radiotherapy between 2000 and 2020 were analyzed, and the risk of CVRD was evaluated using death rates, Fine-Gray competing risks model, standardized mortality ratio (SMR), absolute excess risk (AER), and Cox regression to develop a predictive model. Patients receiving radiotherapy for thoracic cancer had a significantly increased risk of CVRD compared with the general population (Overall AER = 28.59, SMR = 2.37, 95% CI: 2.33-2.40). The risk of CVRD after radiotherapy was significantly lower in the right chest than the left (HR = 0.84, 95% CI: 0.79-0.89) and significantly higher in the left lower lung than in the upper (HR = 1.11, 95% CI: 1.01-1.22). A predictive model for the risk of CVRD in patients with left lower lung after radiotherapy was further constructed (C-index = 0.67, 95% CI: 0.67-0.68). The findings highlight that thoracic radiotherapy significantly increases cardiovascular disease risk, with patients with left lower lung cancer exhibiting the highest CVRD risk. A robust predictive model was developed, offering valuable insights for managing and predicting CVRD risk in thoracic malignancies.