Abstract: Objective To retrospectively analyze the relationship between progression free survival (PFS) and overall survival (OS) in patients with non small cell lung cancer (NSCLC), and to detect the influence of plasma fibrinogen and D-dimer levels before treatment in the prognosis of advanced stage (stage ⅢB-Ⅳ) of NSCLC. Methods The study comprised 134 NSCLC patients with clear pathological diagnosis. All patients were grouped by plasma fibrinogen and D-dimer levels before treatment. We set the normal values of fibrinogen as ≤4 g/L and D-dimer as ≤500 μg/L（FEU). Patients with normal levels of fibrinogen and D- dimer were grouped into low risk group, patients with elevated fibrinogen or D- dimer were grouped into median risk group, and patients with both elevated values were grouped into high risk group. Chi-square test and one way ANOVA analysis were used to analyze the clinicopathologic features of different groups. The OS and PFS in different groups were analyzed by Kaplan- Meier analysis. Univariate analysis of PFS and OS were conducted. Then multivariate analysis was conducted with the Cox regression model in three groups. Results The clinicopathologic features showed no differences between different groups. There were significant differences in OS and PFS between high risk group and other groups. In the survival curves, the high risk group showed poor prognosis. The result of multivariate analysis showed that clinical stage (OS:RR=1.846, 95%CI 1.150-2.964， P=0.011; PFS:RR=1.762, 95%CI 1.190-2.609, P=0.005） and grouped by fibrinogen and D- dimer (OS:RR=1.415， 95% CI 1.050- 1.908， P=0.023； PFS： RR=1.373， 95% CI 1.070- 1.761， P=0.013) were prognostic factors for patients with NSCLC. Conclusion The plasma fibrinogen and D-dimer levels before treatment are closely related with the prognosis of NSCLC patients. And a high plasma fibrinogen and D-dimer levels before treatment are associated with poor prognosis in advanced stage of NSCLC patients.

Key words: carcinoma, non-small-cell lung, fibrinogen, prognosis, antineoplastic combined chemotherapy protocols, survival analysis, D-dimer