Chronic obstructive pulmonary disease (COPD) is associated with shorter survival and marked differences in early stages of non-small cell lung cancer (NSCLC).
Assessing the impact of pre-existing chronic obstructive pulmonary disease (COPD) in patients with non-small cell lung cancer (NSCLC), researchers have determined that COPD is associated with shorter survival and marked differences in early stages of lung cancer.
Among the 66,963 patients diagnosed with NSCLC, the 22,497 with pre-existing COPD had poorer median overall survival compared with patients without comorbid disease (192 days vs 206 days) and had an 11% higher risk of death.
Looking at different stages of NSCLC, median survival decreased among patients with COPD for all stages (stage 1: 692 days vs 1130 days; stage 2: 473 days vs 627 days; stage 3: 224 days vs 255 days; stage 4: 106 days vs 112 days). The elevated risk of death associated with pre-existing COPD decreased with each stage of NSCLC; stage 1 patients had a 39% increased risk of death, stage 2 patients had a 20% higher risk, stage 3 patients had a 9% higher risk, and stage 4 patients had a 4% higher risk.
Older age, gender, race, comorbidity score, and tumor grade were all significantly associated with higher risk of mortality.
“One potential explanation for worse prognosis of lung cancer patients with COPD could be because of inadequate cancer treatments, poor pulmonary function, and lower quality of life,” explained the researchers. They added, “Studies have also shown that COPD was an important predisposing factor for the development of respiratory-related complications and poorer long-term survival outcomes.”
The researchers relied on data from the Surveillance, Epidemiology, and End Results-Medicare database, focusing on patients aged 66 years and older with COPD who were diagnosed with NSCLC at any stage between 2006 and 2010 and who were continuously enrolled in Medicare parts A and B in the 12 months prior to diagnosis.
Also looking at COPD subtypes, the researchers found that chronic bronchitis (11,221 patients) had a more significant impact on time to death compared with emphysema (3475 patients) for all stages of cancer (stage 1: 672 days vs 811 days; stage 2: 445 days vs 582 days; stage 3: 222 days vs 229 days; stage 4: 105 days vs 110 days).
The increased risk of death associated with chronic bronchitis compared with emphysema followed similar patterns seen among the COPD and non-COPD cohorts, with risk of death decreasing with each stage of NSCLC. Stage 1 patients had a 40% higher risk of death, stage 2 patients had a 28% higher risk, stage 3 patients had a 10% higher risk, and stage 4 patients had a 6% higher risk.
While patients with pre-existing emphysema did have an increased risk of death compared with patients without COPD, the mortality risks were lower than chronic bronchitis when compared with the non-COPD group.
Shah S, Blanchette C, Coyle J, Kowalkowski M, Arthur S. Howden R. Survival associated with chronic obstructive pulmonary disease among SEER-Medicare beneficiaries with non-small-cell lung cancer [published online April 29, 2019]. Int J Chron Obstruct Pulmon Dis. doi: 10.2147/COPD.S185837.