Is thrombocytosis a useful prognostic marker in renal cell carcinoma? Results of a single-center retrospective analysis.

Introduction: Our aim was to determine the correlation of platelet count with stage and grade of renal cell carcinoma (RCC) and to determine whether progression of disease was more likely in those with thrombocytosis.

Materials And Methods: A retrospective review of patients with RCC from January 2004 to December 2011 was undertaken. Patients with no preoperative platelet count and those with multiple tumors were excluded. Disease progression was defined as appearance of local recurrence or distant metastasis on follow-up. Thrombocytosis was defined as a platelet count of >400,000/cumm. Standard tests of significance and multivariate analysis using logistic regression were performed.

Results: A total of 322 cases were identified. The median follow-up was 7 months (range, 2-84 months). The platelet count correlated significantly with higher Fuhrmann grade, as well as increasing TNM stage at diagnosis. Patients with a platelet count of >400,000/cumm (n = 35) had a significantly higher mean tumor size and worse grade at diagnosis than those with a normal platelet count (n = 287). Patients with thrombocytosis also had a significantly worse stage at presentation. Progression of disease was seen more often in patients with thrombocytosis (28.6% vs 11.9%, P = 0.07). The median time to progression was significantly faster in patients with thrombocytosis (9 vs 18 months, P = 0.018). However, on multivariate analysis TNM stage was the only significant predictor of time to progression.

Conclusion: Rising platelet count correlated significantly with advancing stage and grade of disease. Patients with thrombocytosis were significantly more likely to have advanced tumors at presentation, poorer histological features, and rapid disease progression.