Plasma fibrinogen level: an independent prognostic factor for disease-free survival and cancer-specific survival in patients with localised renal cell carcinoma

Objectives: To investigate the impact of perioperative plasma fibrinogen level as a biomarker of oncological outcome in localised renal cell carcinoma (RCC). Patients and methods: We consecutively identified 601 patients with localised RCC who underwent curative surgery at a single institution. Subsequent disease recurrence and cancer-specific survival (CSS) were assessed using the Kaplan–Meier method. To evaluate the independent prognostic impact of plasma fibrinogen level, multivariate analysis was performed for these outcomes. Results: Using the defined threshold level of preoperative plasma fibrinogen of ≥420 mg/dL as elevated, we found 56 patients (9.3%) with an elevated plasma fibrinogen level preoperatively. In Kaplan–Meier analysis, there was a significant difference in disease-free survival and CSS rates between patients with and without preoperative plasma fibrinogen levels of ≥420 mg/dL. Multivariate analysis showed that elevated preoperative plasma fibrinogen level was an independent predictor of subsequent disease recurrence and cancer-specific mortality. In a subgroup analysis of the elevated preoperative plasma fibrinogen level group, postoperative normalisation of plasma fibrinogen level was significantly associated with CSS, showing that patients with non-normalised plasma fibrinogen levels tended to have a higher incidence of cancer-specific mortality after surgery. Conclusion: Patients with elevated preoperative plasma fibrinogen levels could be significantly predicted to have subsequent tumour metastasis and cancer-specific mortality, while there was a significant difference in CSS between patients in the normalised and non-normalised postoperative plasma fibrinogen groups. While these are hypothesis generating results, plasma fibrinogen levels may be a useful biomarker due to its low cost and ease of assessment.