Prognostic significance of thrombocytosis in renal cell carcinoma patients

Background: Thrombocytosis has been reported in many types of malignancies and has been studied as a prognostic factor. In the present study, we examined the incidence of thrombocytosis in patients with renal cell carcinoma (RCC) in order to evaluate the prognostic value of thrombocytosis. Methods: One hundred and ninety-six patients treated by radical nephrectomy for RCC were enrolled in this study. We divided the patients into a normal platelet count group and a thrombocytosis group according to the presurgical platelet count. The two groups were compared pathologically and clinically, including prognosis. Results: Thrombocytosis was present in 16 patients (8.2%). Platelet counts had normalized after nephrectomy in all patients with thrombocytosis. There was no correlation between histological type or grade and thrombocytosis. However, there were correlations between thrombocytosis and tumor size and tumor stage. Patients with thrombocytosis had a worse prognosis than patients without thrombocytosis (P = 0.0028). When adjusted for stage or tumor size, the correlation was limited to low stage (stage 1 + 2: P = 0.0041, stage 3 + 4: P = 0.2983) or small tumors (tumor size: less than or equal to4 cm, P = 0.0021; 4-7 cm, P = 0.0142; >7 cm, P = 0.8158). Conclusion: Thrombocytosis is an inexpensive and easy tool with which to evaluate the prognosis of RCC patients in daily medical practice.