EGFR and chronic obstructive pulmonary disease: After multivariate regression analysis, it was demonstrated that CPI ≥ 40 (HR: 2.087, 95% CI: 1.715–6.089, p = 0.012), coexistence of COPD (HR: 2.281, 95% CI: 1.139–4.569, p = 0.040), isolated IPF (HR: 5.703, 95% CI: 2.516–12.925, p = 0.000), or CPFE (HR: 6.275, 95%CI: 3.379–11.652, p = 0.000) were independent risk factors of poor prognosis after adjusting for age, sex, smoking history, EGFR mutation, and tumor stage (Table 5).