Abstract
BACKGROUND: To investigate the correlation between the preoperative systemic immune-inflammation index (pSII) and postoperative pneumonia (POP) in surgical non-small cell lung cancer patients. METHODS: Patients who underwent lung cancer surgery at West China Hospital of Sichuan University were retrospectively included. The indicators were collected, including basic information of patients, surgery-related variables and POP rate. The predictive value of the pSII in the occurrence of POP was analyzed. RESULTS: A total of 1486 patients (male: 748, 50.3%; female: 738, 49.7%; mean age: 58.2 ± 9.7 years; median age: 59 years old, interquartile range: 51-65 years old) were finally included in the study, of which 142 patients had POP with an incidence of 9.5% (142/1486), 9.2% (69/748) in males, and 9.9% (73/738) in females. The proportion of patients with diabetes in the pneumonia group was significantly higher than that in the nonpneumonia group (9.8%, 14/142 vs. 5.6%, 75/1344, p = 0.041). Compared with the nonpneumonia group, the level of the preoperative body mass index (24.2 [21.9, 26.1] vs. 23.1 [21.1, 25.2], p = 0.003) and SII (487 [350, 673] vs. 345 [230, 500], p < 0.001) in the pneumonia group were significantly higher. Multiple factor analysis showed that the pSII (odds ratio: 1.001, 95% confidence interval: 1.000-1.001, p < 0.001) was an independent risk factor for POP (487 [350, 673] vs. 345 [230, 500], p < 0.001); receiver operating characteristic curve analysis showed that the pSII was effective in predicting POP (area under curve: 0.751, p < 0.001). CONCLUSION: The pSII is closely related to and can effectively predict the occurrence of POP after lung cancer surgery.