Venous Thromboembolism in Peritoneal Mesothelioma: Uncovering the Hidden Risk

Introduction: Venous thromboembolism (VTE) is a common complication in patients with abdominal malignancies. Despite known associations between pleural mesothelioma and increased VTE risk, the characteristics of VTE in patients with peritoneal mesothelioma (PeM) remain undescribed. Methods: Patients treated for PeM were retrospectively identified from our institutional database. The frequency of VTE was assessed and logistic regression modeling was employed to assess VTE risk factors. The association between VTE and overall survival was also ascertained. Recommended thromboprophylaxis for patients who underwent surgery at our institution comprised a single preoperative dose of prophylactic anticoagulation, followed by daily dosing for four weeks postoperatively. Results: Among 120 PeM patients, 26 (21.7%) experienced VTE, including 19/91 (20.9%) surgical patients, 4/23 (17.4%) patients who received systemic therapy, and 3/6 (50%) patients who underwent observation (p = 0.21). Most events were symptomatic (n = 16, 62%) and were attributable to pulmonary emboli (n = 16, 62%). The 90-day postoperative VTE rate was 4.4% (4/91), including 1 of 60 patients who underwent index surgical intervention at our institution and 3 patients with surgery elsewhere. A low serum albumin concentration was associated with VTE in non-surgical patients (odds ratio 0.12, confidence interval [CI] 0.02–0.72; p = 0.03). No significant difference in overall survival was observed between patients with and without VTE (median 46.0 months [CI 24.9–67.0] vs. 55.0 months [CI 27.5–82.5]; hazard ratio 0.98 [CI 0.54-1.81], p = 0.98). Conclusions: A high risk of VTE was observed in PeM patients, warranting suspicion throughout the disease trajectory. Postoperative VTE rates were within acceptable limits with 4-week thromboprophylaxis.