Association of clear cell carcinoma of the endometrium with a high rate of venous thromboembolism.

Objective: To document the rate of clinically significant venous thromboembolism (VTE) in patients with clear cell carcinoma of the endometrium (CCC-E).

Study Design: Institutional review board permission was obtained to identify all cases of CCC-E between 1994 and 2004. Controls with high grade endometrial cancers were matched for stage, age and date of diagnosis.

Results: Complete data were available for 29. Age ranged from 38 to 85 (mean, 64.6) years. Thirty-five percent of the patients had stage I tumors, 10% stage II, 27.5% stage III and 27.5% stage IV tumors. Fifty-eight matched controls were selected. Overall there were 18 VTE events: 10 (34.5%) in patients with CCC-E and 8 (13.8%) in the controls (OR = 3.68, p = 0.032). More VTE occurred in patients with stage III/IV disease (n = 16) than those with early stage (n = 2). VTE in patients with CCC-E occurred at presentation or with disease recurrence rather than in the postoperative period (8 vs. 1). Among patients with CCC-E, VTE had an adverse effect on survival, with a hazard ratio of 3.65 (95% CI, 3.14-4.16; p = 0.011).

Conclusion: Patients with CCC-E have greater risk of VTE than patients with other high-risk endometrial cancers. Consideration should be given to extended prophylaxis in patients with CCC-E to prevent VTE.