Cardiovascular comorbidities and survival of lung cancer patients: Medicare data based analysis

Objectives: To evaluate the role of cardiovascular disease (CVD) comorbidity in survival of patients with non-small cell lung cancer (NSCLC). Materials and methods: The impact of seven CVDs (at the time of NSCLC diagnosis and during subsequent follow-up) on overall survival was studied for NSCLC patients aged 65+ years using the Surveillance, Epidemiology, and End Results data linked to the U.S. Medicare data, cancer stage- and treatment-specific. Cox regression was applied to evaluate death hazard ratios of CVDs in univariable and multivariable analyses (controlling by age, TNM statuses, and 78 non-CVD comorbidities) and to investigate the effects of 128 different combinations of CVDs on patients' survival. Results: Overall, 95,167 patients with stage I (n =29,836,31.4%), II (n =5133,5.4%), IIIA (n = 11,884,12.5%), IIIB (n = 18,020, 18.9%), and IV (n =30,294, 31.8%) NSCLC were selected. Most CVDs increased the risk of death for stages I IIIB patients, but did not significantly impact survival of stage IV patients. The worse survival of patients was associated with comorbid heart failure, myocardial infarction, and cardiac arrhythmias that occurred during a period of follow-up: HRs up to 1.85 (p <0.001), 1.96 (p <0.05), and 1.67 (p <0.001), respectively, varying by stage and treatment. The presence of hyperlipidemia at baseline (HR down to 0.71, p< 0.05) was associated with better prognosis. Having multiple co-existing CVDs significantly increased mortality for all treatments, especially for stages I and II patients treated with surgery (HRs up to 2.89, p <0.05) and stages I IIIB patients treated with chemotherapy (HRs up to 2.59, p <0.001) and chemotherapy and radiotherapy (HRs up to 2.20, p <0.001). Conclusion: CVDs impact the survival of NSCLC patients, particularly when multiple co-existing CVDs are present; the impacts vary by stage and treatment. This data should be considered in improving cancer treatment selection process for such potentially challenging patients as the elderly NSCLC patients with CVD comorbidities. (c) 2015 Elsevier Ireland Ltd. All rights reserved.