Postoperative infection risk factors in lung cancer patients after bronchoalveolar lavage

Lung cancer is a malignant tumor with high incidence and mortality worldwide. Bronchoalveolar lavage (BAL) is an important tool for its diagnosis and evaluation. However, as an invasive procedure, it may carry a risk of secondary infection. This study aimed to investigate the incidence and independent risk factors of secondary pulmonary infection following BAL in patients with lung cancer.

A retrospective cohort study was conducted, enrolling 1,027 patients with lung cancer who underwent BAL at Taizhou Hospital of Zhejiang Province, China, from January 2022 to March 2025. Patients were divided into an infection group and a non-infection group based on the occurrence of postoperative pulmonary infection. Univariate analysis was used to compare clinical data, imaging characteristics, and BAL procedural parameters between the two groups. Variables with P<0.05 in the univariate analysis and clinically relevant factors were incorporated into a multivariate Poisson regression model to identify independent risk factors for postoperative infection.

In this study, the incidence of secondary pulmonary infection after BAL in lung cancer patients was 2.63% (23/875). Univariate analysis showed that the proportion of patients with an Eastern Cooperative Oncology Group performance status (ECOG PS) score ≥3 (21.7% vs. 4.5%, P=0.004), total lavage volume [150 (135, 200) vs. 100 (100, 120) mL, P<0.001], and the proportion of upper lobe lavage (73.9% vs. 47.8%, P=0.02) were significantly higher in the infection group compared with the non-infection group. Multivariate Poisson regression analysis revealed that PS score ≥3 [relative risk (RR) 4.24, 95% confidence interval (CI): 1.62-11.10, P=0.003], total lavage volume (per 10 mL increase, RR 1.34, 95% CI: 1.23-1.46, P<0.001), and the presence of necrosis/cavitation within the tumor (RR 2.60, 95% CI: 1.04-6.53, P=0.042) were independent risk factors for post-BAL infection.

The incidence of secondary pulmonary infection following BAL in patients with lung cancer is 2.63%. A PS score ≥3, intratumoral necrosis/cavitation, and a higher total lavage volume are independent risk factors for postoperative pulmonary infection, with total lavage volume showing a clear dose-response relationship with infection risk. For patients with these high-risk factors, clinicians should carefully evaluate the lavage volume and strengthen peri-procedural management.