Methods: Twenty-eight patients (27 males, 1 female; mean age 65.9±7.6 years; range 48 to 79 years) with lung cancer undergoing lung resection between August 2010 and December 2011 were enrolled in the study. None had fever, empyema or signs of lower respiratory tract infection. Bronchial lavage samples were collected from both sides of main bronchial systems right before the operation and from the operated bronchus right after the operation.

Results: No significant difference was observed between preoperative bronchial cytokines of both bronchial sites (with and without tumor). Tumor-side bronchial IL-6 and TNF-a were significantly increased after the operation compared to preoperative levels (p=0.001, p=0.045). Compared to lobectomy, IL-6 levels of the patients who underwent pneumonectomy were significantly higher (p=0.004). Significant difference was observed between preoperative contralateral bronchial IL-8 levels of patients in whom decortication was performed as an additional operational procedure and those underwent an isolated lung resection (p=0.017). There was a positive correlation between stage, stage subgroup, and preoperative contralateral bronchial IL-6 levels (p=0.005, p=0.027). Postoperative IL-6 levels were found to be higher in patients with lymphovascular invasion (p=0.008).

Conclusion: Bronchial cytokines, IL-6 and TNF-a levels, were markers of surgical injury on the tumor side from bronchial system following operation. As the tumor stage increases, the entire lungs are affected and the inflammatory response is expanded to contralateral hemithorax. Postoperative IL-6 levels may be an indicator of lymphovascular invasion. The extensiveness of the operation also affects the inflammatory response; IL-6 levels of the patients undergoing pneumonectomy may have significantly higher than lobectomy. Thus, it shows a relationship between IL-6 synthesis and the degree of surgical injury.