Evaluating the prognostic significance of preoperative thrombocytosis in epithelial ovarian cancer

Objective Preoperative thrombocytosis has been implicated as a negative prognostic marker for epithelial ovarian cancer (EOC). We assessed whether thrombocytosis is an independent risk factor for EOC recurrence and death. Methods Perioperative patient characteristics and process-of-care variables (National Surgical Quality Improvement Program (NSQIP)-defined) were retrospectively abstracted from 587 women who underwent EOC staging between 1/2/03-12/29/08. Thrombocytosis was defined as platelet count > 450 × 10⁹/L. Disease-free survival (DFS) and overall survival (OS) were determined using Kaplan-Meier methods. Associations were evaluated with Cox proportional hazards regression and hazard ratios (HR). Results The incidence of preoperative thrombocytosis was 22.3%. DFS was 70.8% and 36.0% at 1 and 3 years. OS was 83.3% and 54.3% at 1 and 3 years. Ascites, lower hemoglobin, advanced disease, and receipt of perioperative packed red blood cell transfusion were independently associated with thrombocytosis. Older age and the presence of coronary artery disease were associated with lower likelihood of thrombocytosis. Overall, thrombocytosis was an independent predictor of increased risk of recurrence. Among early stage (I/II) cases, there was a 5-fold increase in the risk of death and nearly 8-fold risk of disease recurrence independently associated with thrombocytosis. Conclusion Preoperative thrombocytosis portends worse DFS in EOC. In early stage disease, thrombocytosis is a potent predictor of worse DFS and OS and further assessment of the impact of circulating platelet-derived factors on EOC survival is warranted. Thrombocytosis is also associated with extensive initial disease burden, measurable residual disease, and postoperative sequelae. Preoperative platelet levels may have value in primary cytoreduction counseling.