Thromboembolic Events During Treatment with Cisplatin-based Chemotherapy in Metastatic Testicular Germ-cell Cancer 2000–2014: A Population-based Cohort Study

BACKGROUND: Cisplatin-based chemotherapy (CBCT) in testicular cancer (TC) is associated with elevated venous thromboembolism (VTE) risk, but trials evaluating the safety and efficacy of thromboprophylaxis are lacking. OBJECTIVE: To evaluate the arterial thromboembolism (ATE) and VTE incidence and risk factors during first-line CBCT for metastatic TC, and the effect of thromboprophylaxis on VTE and bleeding. DESIGN, SETTING, AND PARTICIPANTS: In a population-based study, 506 men administered first-line CBCT during 2000–2014 at three university hospitals in Norway were included. Clinical variables were retrieved from medical records. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Patients with ATE and VTE diagnosed at initiation of or during CBCT until 3 mo after completion were registered. Age-adjusted logistic regression was performed to identify possible VTE risk factors. RESULTS AND LIMITATIONS: Overall, 69 men (13.6%) were diagnosed with 70 thromboembolic events. Twelve men (2.4%) experienced ATE. Overall, 58 men (11.5%) experienced VTE, of whom 13 (2.6%) were prevalent at CBCT initiation, while 45 (8.9%) were diagnosed with incident VTE. Age-adjusted logistic regression identified retroperitoneal lymph node metastasis >5 cm (odds ratio [OR] 1.99, 95% confidence interval [CI] 1.01–3.91), central venous access (OR 2.84, 95% CI 1.46–5.50), and elevated C-reactive protein (>5 mg/l; OR 2.38, 95% CI 1.12–5.07) as incident VTE risk factors. Thromboprophylaxis (n = 84) did not influence the risk of VTE (VTE incidence with or without prophylaxis 13% vs 8%, p = 0.16). The incidence of bleeding events was significantly higher among those who received thromboprophylaxis than among those without thromboprophylaxis (14.5% vs 1.1%, p < 0.001). CONCLUSIONS: We found a high rate of thromboembolism incidence of 13.6%. Thromboprophylaxis did not decrease the risk of VTE but was associated with an increased risk of bleeding. PATIENT SUMMARY: We found a high rate of thromboembolism (13.6%) during cisplatin-based chemotherapy for metastatic testicular cancer. Prophylactic treatment against thromboses did not reduce the thrombosis frequency, but it resulted in a high incidence of bleeding events.