BACKGROUNDThe coagulation function in carcinoma patients is abnormal, but in renal cell carcinoma the extent and relationships of coagulation function remain unclear. This study retrospectively investigated the relationships between coagulation function, clinical stage and metastasis in patients with renal cell carcinoma.

METHODSA total of 350 consecutive patients admitted to our Urology Department from 2004 to 2010 were diagnosed with renal cell carcinoma by histopathologic examination and were included in this study. A total of 231 cases of renal benign tumors were considered as the control group. Fibrinogen, prothrombin time, activated partial thromboplastin time and international normalized ratio were evaluated in all subjects. Tumor size, clinical stage, lymph node metastasis, and distant metastasis were evaluated using radiologic imaging, intraoperative findings, and histological studies.

RESULTSThe preoperative plasma fibrinogen levels of patients with renal cell carcinoma ((383.9 ± 146.7) mg/dl) were significantly higher than those of the control group ((316.7 ± 62.0) mg/dl) (P < 0.01). We divided the renal cell carcinoma group into stages Ia, Ib, II, III, and IV. The fibrinogen values were (315.6 ± 64.6) mg/dl, (358.3 ± 91.1) mg/dl, (465.6 ± 164.7) mg/dl, (500.0 ± 202.1) mg/dl, and (585.8 ± 179.7) mg/dl, respectively. There were no significant differences in fibrinogen values between stage Ia and control groups. However, results of other stages showed significant differences when compared to control group values (P < 0.01). Using the cutoff value of 440 mg/dl, which defines hyperfibrinogenemia, plasma fibrinogen levels had a positive predictive value of 39.8% and a negative predictive value of 93.3% for predicting distant metastasis, with a sensitivity of 64.7% and specificity of 83.3%.

CONCLUSIONSPreoperative plasma fibrinogen levels are elevated in patients with renal cell carcinoma with distant metastasis or lymph node metastasis. Potential metastasis is more likely if the tumor size larger than 4 cm. Increased preoperative plasma fibrinogen levels, especially hyperfibrinogenemia, may be an indicator of metastasis.