AbstractBackgroundUnderstanding cancer treatment–related cardiovascular (CV) events is important for cancer care; however, comprehensive evaluation of CV events in patients with lung cancer is limited. This study aimed to assess the cumulative incidence and associated risks of various CV event types in patients with non–small cell lung cancer (NSCLC).MethodsA total of 7868 individuals aged 40 years and older, recently diagnosed with NSCLC (2007–2018), were assessed with data obtained from the National Cancer Center, Korea. This study included nine types of CV events. A 2‐year cumulative incidence function (CIF) of CV events was estimated, with death as a competing event. The associated risks were assessed by subdistribution hazard ratio (sHR) in the Fine–Gray competing risks model.ResultsCV events were observed in 7.8% of patients with NSCLC, with the most frequently observed types being atrial fibrillation and flutter (AF) (2.7%), venous thromboembolic disease (2.0%), and cerebrovascular disease (CeVD) (1.5%). Overall, all CV events were highest in the group treated with systemic therapy (CIF, 10.6%; 95% confidence interval [CI], 9.5%–11.8%), followed by those treated with surgery (CIF, 10.0%; 95% CI, 8.6%–11.6%); the incidence of AF (CIF, 5.7%; 95% CI, 4.6%–7.0%) was highest in patients treated with surgery. Individuals treated with systemic therapy were found to exhibit a higher CeVD risk than those treated with surgery (sHR, 4.12; 95% CI, 1.66–10.23). Among the patients who underwent surgery, those with lobectomy and pneumonectomy had a higher AF risk (vs. wedge resection/segmentectomy; sHR, 7.79; 95% CI, 1.87–32.42; sHR, 8.10; 95% CI, 1.60–40.89).ConclusionsThese findings revealed treatment‐related CV event risks in patients with NSCLC, which suggests that the risk of AF in surgery and CeVD in systemic therapy should be paid more attention to achieve a better prognosis and improve cancer survivorship outcomes.Plain Language Summary Atrial fibrillation and flutter (AF) is the most common cardiovascular event, particularly at a high risk in patients with non–small cell lung cancer (NSCLC) undergoing surgery. Patients receiving surgery with poor performance status, diagnosed with regional stage, and undergoing lobectomy or pneumonectomy are at a high risk of AF. Systemic/radiotherapy is associated with cerebrovascular and ischemic heart disease in patients with NSCLC.