Incidence of venous thromboembolism during chemotherapy for breast cancer: impact on cancer outcome.

BACKGROUND Evidence suggests that cancer patients who develop venous thromboembolism (VTE) have a poorer outcome than those who do not. The aim of this prospective study was to assess the incidence of the development of VTE in breast cancer patients commencing chemotherapy and the relationship between development of thrombosis and cancer progression and death. PATIENTS AND METHODS One hundred and thirty-four breast cancer patients were recruited and followed up prior to chemotherapy and at 3, 6, 12 and 24 months. Duplex ultrasound imaging (DUI) was performed 1 month following commencement of chemotherapy or if patients became symptomatic. RESULTS Thirteen patients developed VTE. Six patients with advanced breast cancer and seven with early breast cancer developed VTE. Three patients died from VTE; all had advanced breast cancer. In patients with VTE, the 28-day mortality rate was 15%, but in patients with symptomatic VTE, the 28-day mortality was 22%. Development of VTE did not predict for progression by three and six months in advanced breast cancer patients. VTE demonstrated a trend for predicting progression by two years. Using Cox regression survival analysis, there was no survival advantage in those with or without VTE. CONCLUSION Although the body of evidence supports a worse prognosis when VTE and cancer coexist as compared to either diagnosis alone, a larger prospective study is required to confirm this and clarify whether any premature death is primarily due to VTE or to more aggressive cancer.