Thrombocytosis is Associated With a Significant Increase in the Cancer Specific Death Rate After Radical Nephrectomy

Abstract

We have previously reported that patients with advanced renal cell carcinoma and a normal platelet count of 400,000/mm. have a 64% increase in life expectancy compared with those with thrombocytosis. We determined whether thrombocytosis was predictive of death from renal cell carcinoma after radical nephrectomy was performed with curative intent for early stage disease. We reviewed the records of 204 patients with renal cell carcinoma who underwent radical nephrectomy with curative intent between June 1993 and January 2000 at Emory University Hospital. Survival, pathological grade and stage were recorded from the Emory Winship Cancer Institute tumor registry. Platelet counts were recorded and any patient with at least 1 platelet count of greater than 400,000/mm. was classified with thrombocytosis. Those with a platelet count of 400,000/mm. were classified with a normal platelet count. There were 26 patients with thrombocytosis and 178 patients with persistently normal platelet counts. The overall and cancer specific death rate in the 26 patients with thrombocytosis was 50% and 42%, respectively. The overall mean time between nephrectomy and death was 12.1 months in this group. The overall and cancer specific death rate in the 178 patients with a normal platelet count was 15.2% and 7.3%, respectively. Mean time to death was 22.6 months in this group. Differences in the overall and cancer specific death rates were highly statistically significant as well as clinically significant. These differences remained significant after controlling for grade, stage and histological type of cancer. This study documents the association of thrombocytosis with decreased survival in patients with renal cell carcinoma. In those who undergo nephrectomy for early stage renal cell carcinoma with a perioperative platelet count of greater than 400,000/mm. the cancer specific death rate from renal cell carcinoma is greater than 5 times the rate in patients with a persistently normal platelet counts after radical nephrectomy. The platelet count appears to be a new and powerful independent prognosticator in patients with renal cell carcinoma who undergo radical nephrectomy for presumed localized disease.