Survival associated with chronic obstructive pulmonary disease among elderly patients with non-small cell lung cancer.

Abstract

e18107 Background: Lung cancer and chronic obstructive pulmonary disease (COPD) are among leading causes of morbidity and mortality worldwide. The association between pre-existing COPD and overall survival (OS) among patients with non-small cell lung cancer (NSCLC) remains unclear. We investigated the impact of pre-existing COPD and its subtypes: chronic bronchitis and emphysema on OS in elderly patients diagnosed with NSCLC at different stages. Methods: Using SEER-Medicare data, we identified patients diagnosed with NSCLC between January 1, 2006 and December 31, 2010, > 66 years of age, and continuously enrolled in Medicare Parts A and B in the 12 months prior to diagnosis. Pre-existing COPD in patients with NSCLC were identified using ICD-9 codes. Kaplan Meier method and log-rank tests were used to examine OS by COPD status and COPD subtype. Cox proportional hazards models were fit to assess the risk of death after cancer diagnosis while adjusting for baseline factors. Results: We identified 66,963 patients with NSCLC. Of these, 22,497 (33.60%) had documented COPD before NSCLC diagnosis. For each stage of NSCLC, median OS was shorter in the COPD compared to the non-COPD group (stage I: 692 vs 1130 days, P < 0.0001; stage II: 473 vs 627 days, P < 0.0001; stage III: 224 vs 229 days; P < 0.0001; stage IV: 106 vs 112 days, P < 0.0001). For COPD subtype, median OS for patients with pre-existing chronic bronchitis was shorter compared to emphysema across all stages of NSCLC (stage I: 672 vs 811 days, P < 0.0001; stage II 582 vs 445 days, P < 0.0001; stage III: 255 vs 229 days, P < 0.0001; stage IV: 105 vs 112 days, P < 0.0001). After multivariable adjustment, COPD patients exhibited an 11% shorter time to death compared to non-COPD patients (Hazard Ratio: 1.11, 95% Confidence Interval: 1.09—1.13). Conclusions: There were marked differences in early stage NSCLC, with a decrease in OS from stage I to stage IV in the COPD group. Patients with chronic bronchitis had shorter OS at every stage of NSCLC compared to emphysema. The results may help inform early detection strategies for NSCLC and treatment selection in early and advanced cancer.