The Efficacy and Safety of Oral Anticoagulation in Patients with Cancer

OBJECTIVES: To compare the complication rate (bleeding and thrombosis) of oral anticoagulation in a cohort of patients with cancer to a cohort without cancer. DESIGN: Prospective cohort study. SETTING: Outpatient anticoagulation clinic in a community hospital. PATIENTS: Consecutive patients enrolled in an anticoagulation clinic: 44 with cancer, 64 without cancer. INTERVENTIONS: Patients received prophylactic doses of Warfarin (target INR 2-3 in the majority of instances) and complication rates were assessed. MEASUREMENTS: Major bleeding (strictly defined), minor bleeding, recurrent thrombosis, proportion of time with therapeutic INR, frequency of clinic visits. RESULTS: The rates of major bleeding, minor bleeding, and recurrent thrombosis were not statistically significantly different in the two groups of patients. Therapeutic INR's were more difficult to sustain in the cancer patients as compared to the non-cancer patients (43.3% vs 56.9%, p < 0.0001). There was a non significant trend towards more frequent monitoring for the cancer patients compared with the non-cancer patients (4.6 vs 3.5 visits per treatment month, p = 0.14). CONCLUSIONS: Oral anticoagulation is safe and effective in the patient with cancer. It is more difficult to sustain a therapeutic INR in the cancer patients and they may need more frequent monitoring to achieve a low complication rate.