The oncology treatment of patients who use oral anticoagulants is connected with high risk of bleeding complications.

The data about risk for bleeding complications during anticoagulation in cancer patients with different oncology treatment are conflicting. To investigate the rate of bleeding in the course of oral anticoagulants, during treatment of malignant diseases, we conducted a retrospective study including 75 patients on stable anticoagulation prior to commencing their different oncology treatment. All patients were treated according to the consiliar decision, made based on the localization and pathohistological findings of the malignant disease. During their treatment the regular laboratory monitoring of INR was done. Every dose of oral anticoagulants, INR changes, as well as the size and localization of bleeding were recorded. During all the malignancy treatment 22 (30%) of patients were overanticoagulated. In 15 (20%) patients it was associated with bleeding, while 3 (4%) of them had to be transfused with fresh frozen plasma to stop the major bleeding. Most bleeding complications occurred in the group of patients treated with chemotherapy or with analgesics in the group with advanced disease. None of the bleeding complications were observed in patients treated with irradiation and surgery alone, where the bridging of oral anticoagulants with low molecular weight heparin was done before surgery. The oncology treatment of patients who take oral anticoagulants was connected with high risk for bleeding especially if chemotherapy as a therapeutic options was used. Therefore physicians should be aware of this risk and carefully monitor the intensity of anticoagulant therapy, especially during the first treatment weeks when the risk of bleeding is greatest.

Factor V Leiden mutation and high FVIII are associated with an increased risk of VTE in women with breast cancer during adjuvant tamoxifen - results from a prospective, single center, case control study.

BACKGROUND: Estimates of the risk ratio of tamoxifen-associated venous thromboembolism (VTE) in breast cancer patients range from 2.4 to 7.1. The occurrence of thrombosis in patients with breast cancer complicates the clinical condition and causes a change of treatment. Our study was conducted in order to investigate the influence of patient-related risk factors for thrombosis development in breast cancer patients whose treatment included adjuvant tamoxifen. METHODS: The prospective, single center, case control study included 150 breast cancer women, 50 whom developed venous thrombosis during adjuvant tamoxifen and 100 whom did not have thrombosis, as a control group. Patient-related risk factors such as: age, body mass index, previous VTE, varicose veins, concomitant diseases, the presence of prothrombotic mutations (FV Leiden, FII G20210A) and FVIII activity were evaluated in both groups. RESULTS: In respect of prothrombotic mutations, the FV Leiden mutation was present in a higher number of women from the VTE group (10/50 vs 7/100; P=0.020). Additionally, FVIII activity was significantly higher in the VTE group; median (IQR), of 1.79 (0.69) vs 1.45 (0.55); P<0.001 and more women in this group (24/50 vs 34/100) had increased FVIII activity; P=0.020. In those women with FVIII>1.5IU/ml, who were carriers of prothrombotic mutations, an OR of 3.76 (CI 95% 1.276-11.096; P=0.016) was obtained for VTE. CONCLUSION: The results of our study showed that the factor V Leiden mutation and high FVIII are associated with an increased risk of VTE in women with breast cancer during adjuvant tamoxifen.