Deaths from COPD in patients with cancer: a population-based study

Features of the deaths caused by COPD (chronic obstructive pulmonary disease) in cancer patients remained a controversial issue. This study aimed to characterize the demographic characteristics and mortality rates of the deaths from COPD in patients with cancer. In total, 7,846,370 cancer patients aged 40 years or older in the United States were identified from the Surveillance, Epidemiology, and End Results database (1975-2016). Mortality rates and SMRs (standardized mortality ratios) adjusted by age, race, sex, and calendar year were calculated to investigate the risk of COPD deaths in cancer survivors and to compare it with the general population. A total of 119,228 COPD deaths in patients with cancer were recorded, with a mortality rate of 261.5/100,000 person-years, nearly two-fold that of the general population (SMR, 2.17; 95% CI [confidence interval], 2.16-2.18). The proportion of cancer survivors dying from COPD increased from 0.9% in 1975 to 3.4% in 2016. Patients with lung cancer had a higher overall risk (SMR, 9.23; 95% CI, 9.12-9.35) than those with extrapulmonary malignancies. Among all extrapulmonary sites, laryngeal (SMR, 5.54; 95% CI, 5.34-5.75) and esophageal cancers (SMR, 4.33; 95% CI, 4.04-4.63) had the highest SMR. The risk of death from COPD increased with follow-up time.