Prophylactic anticoagulation with the low-molecular-weight heparin semuloparin reduced the incidence of thromboembolic events without increasing the risk for major bleeding.

Venous thromboembolism (VTE) often complicates cancer and is related to patient performance status, tumor stage, and treatment. Many chemotherapeutic agents increase the risk for VTE, even in ambulatory outpatients. However, whether prophylactic anticoagulation diminishes VTE risk during chemotherapy is unclear.

To address this issue, an international team of investigators conducted an industry-supported, randomized, double-blind, placebo-controlled trial involving 3212 patients who were beginning to receive chemotherapy for cancers typically associated with an increased risk for VTE; 36% of patients had lung cancer, and 28.9% had colorectal cancer. Most tumors (66%) were metastatic; the remaining tumors were locally advanced. Patients with adequate renal function (creatinine clearance >30 mL/minute) received either the hemisynthetic low-molecular-weight heparin (LMWH) semuloparin (20 mg/day subcutaneously) or placebo for a median 3.5 months.

The primary outcome — any symptomatic deep venous thrombosis (DVT), nonfatal pulmonary embolism (PE), or death related to VTE — occurred in fewer semuloparin recipients than placebo recipients (1.2% vs. 3.4%; hazard ratio, 0.36; P<0.001). Semuloparin was also associated with significantly lower risk for DVT (odds ratio, 0.32; 95% confidence interval, 0.15–0.62) and PE (OR, 0.41; 95% CI, 0.19–0.85). However, overall survival was similar in both groups. Rates of major bleeding and nonmajor clinically relevant bleeding were low (about 2%), and other adverse events were also similar in both groups.

Comment: The decision to administer anticoagulant prophylaxis to patients receiving chemotherapy is informed by several factors: the nature of the chemotherapy, patient characteristics, tumor type and stage, and the safety and efficacy of available antithrombotic agents. This trial demonstrates that in carefully selected patients with high-risk tumors, LMWH — which is simple to administer without monitoring — safely reduced the incidence of VTE when given concomitantly with chemotherapy.

Source: Journal Watch Oncology and Hematology