Comorbidity and survival in lung cancer patients

Background: As the population of the United States ages, there will be increasing numbers of lung cancer patients with comorbidities at diagnosis. Comorbid conditions are important factors in both the choice of the lung cancer treatment and outcomes. However, the impact of individual comorbid conditions on patient survival remains unclear. Methods: A population-based cohort study of 5,683 first-time diagnosed lung cancer patients was captured using the Nebraska Cancer Registry (NCR) linked with the Nebraska Hospital Discharge Data (NHDD) between 2005 and 2009. A Cox proportional hazards model was used to analyze the effect of comorbidities on the overall survival of patients stratified by stage and adjusting for age, race, sex, and histologic type. Results: Of these patients, 36.8% of them survived their first year after lung cancer diagnosis, with a median survival of 9.3 months for all stages combined. In this cohort, 26.7% of the patients did not have any comorbidity at diagnosis. The most common comorbid conditions were chronic pulmonary disease (52.5%), diabetes (15.7%), and congestive heart failure (12.9%). The adjusted overall survival of lung cancer patients was negatively associated with the existence of different comorbid conditions such as congestive heart failure, diabetes with complications, moderate or severe liver disease, dementia, renal disease, and cerebrovascular disease, depending on the stage. Conclusions: The presence of comorbid conditions was associated with worse survival. Different comorbid conditions were associated with worse outcomes at different stages. Impact: Future models for predicting lung cancer survival should take individual comorbid conditions into consideration.