Correlation of percentage changes in platelet counts with recurrence rate following radical nephrectomy

Objectives: To categorize and correlate percentage changes in platelets counts - an objective approach with recurrence rate following radical nephrectomy. Materials and Methods: All consecutive patients who had radical nephrectomy for localized renal tumor in the period from January 1997 to December 2005 have been included in this study. The data was collected retrospectively. The primary outcome of this study was over all and cancer- specific survival and its correlation with percentage change in platelet count from pre-surgical level. Change in platelets counts was categorized as less than or more than 0-10%, 10-20% and more than 20% from base line (pre-surgery). This was correlated with the follow-up recurrence and disease free survival. Survival distribution were estimated using Kaplan-Meier method, univariate and multivariate regression analyses were performed using Cox proportional hazards models to address the impact of different prognostic factors on survival. Results: Of the 237 patients treated with radical nephrectomy, pT1, pT2, pT3, and pT4 accounted for 116 (49%), 44 (18.5%), 68(28.7%), and nine (3.8%) cases respectively. The mean tumor size was 6.3 cm (Range: 4-17 cm; SD: 3). The pre-operative platelet count ranged from 82 to 1573 (Mean: 327.5; SD: 171.7). The overall follow-up time ranged from 1-102 months (Mean: 39 months; SD: 27months). There was significant correlation between the recurrence rate and increase in platelets count of more than 20% following radical nephrectomy (P value- 0.0001). Conclusions: Categorization of platelets changes following radical nephrectomy for localized renal cell carcinoma, in particular, a change in more than 20% can accurately predict recurrence and cancer specific survival following radical nephrectomy for localized renal cell carcinoma.