Purpose: Fibrinogen plays an important role in the pathophysiology of tumour cell invasion and metastases. In recent studies, an elevated plasma fibrinogen level has been associated with poor prognosis in different types of cancer. The present study was performed to analyse the prognostic impact of an elevated fibrinogen level in prostate cancer patients.
Methods: We evaluated data from 268 prostate cancer patients who underwent 3D conformal radiotherapy between 1999 and 2006 at a single tertiary academic center. Cancer-specific survival (CSS), overall survival (OS), and clinical disease-free survival (DFS) were assessed using the Kaplan-Meier method. Univariable and multivariable Cox regression models were performed for each endpoint.
Results: Applying receiver operating characteristics (ROC) curve analysis, the optimal cut-off level for the plasma fibrinogen level was 530 mg dl(-1), respectively. Univariable (HR 3.638, 95 % CI 1.15-11.47, p = 0.027) and multivariable analyses (HR 3.964, 95 % CI 1.06-14.87, p = 0.041) revealed a significant correlation between increased plasma fibrinogen and CSS. Univariable analysis also showed a significant association between the elevated plasma fibrinogen level and decreased OS (HR 3.242, 95 % CI 1.53-6.89, p = 0.002), that remained significant in multivariable analysis (HR 3.215, 95 % CI 1.44-7.19, p = 0.004). No significant associations were found for clinical DFS.
Conclusion: Although our data show a significant association between an elevated plasma fibrinogen level and poor prostate cancer prognosis, they have to be interpreted cautiously. Limitations of the present study are caused by its retrospective design, the limited accuracy obtained using ROC curve analysis, and potential confounding factors like cardiovascular disease and inflammatory diseases that have not been accounted for.
Keywords: Coagulation; Fibrinogen; Prognosis; Prostate cancer; Radiotherapy.