Background: Pulmonary diseases [asthma, chronic obstructive pulmonary disease (COPD), and tuberculosis (TB)] are associated with lung cancer mortality. However, the relationship between coexisting pulmonary diseases and survival in patients with lung squamous cell carcinoma (SqCC) has not been well defined.
Methods: Patients newly diagnosed with SqCC between 2003 and 2008 were identified by linking the National Health Insurance Research Database and Taiwan Cancer Registry Database. Cases with SqCC were followed up until death, loss to follow-up, or study end in 2010. Information on health status, date of death and the main causes of death was ascertained from the National Death Registry Database. Cox proportional hazard regression was used to calculate the hazard ratio (HR) of coexisting asthma, COPD and/or TB.
Results: During the study period, a total of 5406 cases with SqCC were enrolled. For all cause-mortality, HRs were 1.08 [95% confidence interval (CI), 0.99-1.18], 1.04 (95% CI, 0.97-1.12), and 1.14 (95% CI, 1.00-1.31) for individuals with asthma, COPD, and TB, respectively. Specifically, among men with coexisting pulmonary diseases, the HRs were 1.56 (95% CI, 1.23-1.97) and 1.11 (95% CI, 1.00-1.24) for individuals with asthma+COPD+TB and asthma+COPD, respectively. Among male patients with stage III SqCC, HRs were 3.41 (95%CI, 1.27-9.17) and 1.65 (95%CI, 1.10-2.47) for individuals with asthma+TB and asthma+COPD+TB, respectively. Among male patients with stage IV SqCC, HRs were 1.40 (95%CI, 1.00-1.97) and 1.25 (95%CI, 1.03-1.52) for individuals with asthma+ COPD+TB and asthma. Among female patients with stage I and II, HR was 0.19 (95%CI, 005-0.77) for individuals with asthma.
Conclusions: Coexisting pulmonary diseases increased the risk of mortality from SqCC in male patients. For female patients with early stage SqCC, pre-existing asthma decreased mortality. These patients deserve greater attention while undergoing cancer treatment.