High plasma fibrinogen level represents an independent negative prognostic factor regarding cancer-specific, metastasis-free, as well as overall survival in a European cohort of non-metastatic renal cell carcinoma patients

BACKGROUND: In recent years, plasma fibrinogen has been ascribed an important role in the pathophysiology of tumour cell invasion and metastases. A relatively small-scale study has indicated that plasma fibrinogen levels may serve as a prognostic factor for predicting clinical outcomes in non-metastatic renal cell carcinoma (RCC) patients. METHODS: Data from 994 consecutive non-metastatic RCC patients, operated between 2000 and 2010 at a single, tertiary academic centre, were evaluated. Analyses of plasma fibrinogen levels were performed one day before the surgical interventions. Patients were categorised using a cut-off value of 466 mg dl⁻¹ according to a calculation by receiver-operating curve analysis. Cancer-specific (CSS), metastasis-free (MFS), as well as overall survival (OS) were assessed using the Kaplan-Meier method. To evaluate the independent prognostic impact of plasma fibrinogen level, a multivariable Cox regression model was performed for all three different endpoints. RESULTS: High plasma fibrinogen levels were associated with various well-established prognostic factors, including age, advanced tumour stage, tumour grade and histologic tumour necrosis (all P<0.05). Furthermore, in multivariable analysis, a high plasma fibrinogen level was statistically significantly associated with a poor outcome for patients' CSS (hazard ratio (HR): 2.47, 95% confidence interval (CI): 1.49-4.11, P<0.001), MFS (HR: 2.15, 95% CI: 1.44-3.22, P<0.001) and OS (HR: 2.48, 95% CI: 1.80-3.40, P<0.001). CONCLUSION: A high plasma fibrinogen level seems to represent a strong and independent negative prognostic factor regarding CSS, MFS and OS in non-metastatic RCC patients. Thus, this easily determinable laboratory value should be considered as an additional prognostic factor for RCC patients' individual risk assessment.