The Prognostic Significance of Thrombocytosis in Epithelial Ovarian Carcinoma

Objective: The objective of this study was to determine the incidence of thrombocytosis in epithelial ovarian carcinoma and examine associations with clinico-pathologic features. Thrombocytosis (platelet counts >400 x 10(9)/l) has been identified as a poor prognostic factor in many cancers. Platelet-secreted factors may contribute to metastasis, invasion, and primary tumor growth.

Methods: One hundred eighty-three patients with invasive epithelial ovarian or primary peritoneal carcinomas were identified between January 1996 and December 2000. Records were retrospectively reviewed and data analyzed using chi(2), Student's t test, and Cox proportional hazards model; survival was analyzed by the method of Kaplan and Meier.

Results: Forty-one of 183 (22.4%) patients had thrombocytosis at primary diagnosis. Patients with preoperative thrombocytosis were found to have greater elevations of CA-125 (P = 0.026), more advanced stage disease (P = 0.016), higher grade tumors (P = 0.010), more frequent lymph node metastases (P = 0.018), and greater volume of ascites (P < 0.0001). One hundred sixty of 183 (87.4%) patients achieved optimal cytoreduction; patients with thrombocytosis demonstrated a greater likelihood of suboptimal resection (residual disease >1 cm; 19/41 vs. 4/142 in patients without thrombocytosis, P < 0.0001). Patients with thrombocytosis had a shorter disease-free interval (12 vs. 34 months, P < 0.0001) and overall survival (28 vs. 79 months, P < 0.0001). On multivariate analysis, thrombocytosis retained significance as a poor prognostic indicator in patients with stage III and IVA disease (P = 0.04).

Conclusions: Thrombocytosis is a frequent preoperative finding in ovarian and peritoneal carcinomas and may be a marker of aggressive tumor biology.