To investigate the clinical characteristics and risk factors of chronic obstructive pulmonary diseases (COPD) complicated with lung cancer, providing references for its prevention, diagnosis, and treatment in clinical practice.

A total of 210 COPD patients with lung cancer (observation group) and 125 COPD patients without lung cancer (control group) admitted to our hospital from March 2022 to October 2024 were selected. Clinical data and laboratory indicators were collected. Univariate and multivariate logistic regression analyses were performed to identify the clinical features and risk factors associated with COPD complicated with lung cancer.

In the observation group, 184 patients (87.62%) were smokers, and 143 (68.09%) presented with hemoptysis, whereas in the control group, 89 patients (71.20%) were smokers, and only 5 exhibited hemoptysis. The differences between the two groups were statistically significant (P<0.01). No significant differences were observed in family history of lung cancer, occupational exposure, cough, dyspnea, or chest pain between the two groups (P>0.05). A significant difference was noted in platelet count (PLT) between the observation group and the control group: (245.29 ± 91.96)×10⁹/L vs. (213.91±79.21)×10⁹/L (P<0.01). Comparisons of lung tumor markers revealed statistically significant differences between the two groups (P<0.01): carcinoembryonic antigen (CEA) (35.73±170.51 vs. 2.86±1.71 ng/ml), neuron-specific enolase (NSE) (20.96±22.86 vs. 11.72±4.64)ng/ml, cytokeratin 19 fragment antigen (CYFRA21-1) (9.76±23.52 vs. 2.24±2.44)ng/ml, and pro-gastrin-releasing peptide (Pro-GRP) (206.02±693.48 vs. 47.35±18.14)pg/ml. Among the observation group, 169 patients exhibited emphysema on lung CT imaging. Histopathological analysis indicated that 95 cases (45.24%) were squamous cell carcinoma, 141 cases (67.62%) had central-type lung cancer, and 111 patients (52.86%) were at TNM stage Ⅲ at diagnosis. Diagnosis was confirmed via fiberoptic bronchoscopic biopsy in 155 patients (71.43%) and percutaneous lung biopsy in 34 patients (16.19%). Genetic testing was performed in 126 diagnosed patients (60%). Multivariate logistic regression analysis identified smoking history, hemoptysis, PLT ≥ 210.0×10⁹/L, NSE≥13.94 ng/ml, and CYFRA21-1≥3.3 ng/ml as risk factors for COPD complicated with lung cancer (P0.05).

Analysis of clinical characteristics and risk factors in COPD patients with lung cancer revealed that smoking history, hemoptysis, elevated PLT, NSE, and CYFRA21-1 levels are significant risk factors. These findings have clinical implications for the early identification of high-risk lung cancer populations among COPD patients.