Abstract: Objective  To evaluate the prognostic value of pre-treatment system immune-inflammation index(SII) and fibrinogen(FIB) in patients with non-small cell lung cancer(NSCLC).
Methods  The clinical data of patients with pathologically diagnosed NSCLC were collected, and receiver operating characteristic(ROC) curve was used to calculate the optimal cut-off value of pre-treatment SII and FIB as the basis.
Results  The area under the ROC curve(AUC) of pre-treatment SII was 0.748, and the optimal cut-off value was 743.384; the sensitivity and specificity were 57.1% and 90.5% respectively. The AUC of pre-treatment FIB was 0.812, and the optimal cut-off value was 3.070 g/L;the sensitivity and specificity were 85.7% and 64.3% respectively. NSCLC patients in SII>743.384 group and SII≤743.384 group had lower tumor differentiation, late TNM staging, lower KPS score, and different weight loss rate, and there was significant difference(P＜0.05). There were statistically significant differences in age, KPS score, and weight loss of NSCLC patients between the FIB>3.070 g/L group and the FIB≤3.070 g/L group(P＜0.01). The median survival time of SII≤743.384 group and SII＞743.384 group was 34 months and 10 months, respectively, and the difference was statistically significant(P＜0.001). The median survival time was shorter in the FIB≤3.070 g/L group, and was 14 months in the FIB>3.070 g/L group, and the difference was statistically significant(P＜0.01). Combined detection of SII and FIB indicated that the survival time of the group with two indexes increased was shorter than that with one index increased and that without an increase in the two indexes, and the difference was statistically significant(P＜0.01). Cox multivariate analysis showed that weight loss and pre-treatment fibrinogen level were independent risk factors for the prognosis of NSCLC patients(P＜0.05).The results of Spearman correlation analysis suggested that there was a weak positive correlation between SII and FIB(P＜0.05).
Conclusion  Pretreated SII and FIB are closely related to NSCLC, and the increase of SII and FIB indicates poor prognosis.

Key words: carcinoma, non-small-cell lung, system immune-inflammation index, fibrinogen