Background: In the past few years, several studies have been performed to evaluate thrombosis prophylaxis with warfarin in cancer patients with central venous catheters (CVC), but the analysis of these studies does not allow firm conclusions to be drawn.
Patients and methods: Four hundred and twenty-seven cancer patients were evaluated. Each received warfarin at a dose of 1 mg/daily as prophylaxis, starting the day after CVC positioning until its removal.
Results: The catheters were monitored for a mean of 168 days (range 22-706). There were 9 thrombotic events (1.8%). Overall, International Normalised Ratio (INR) elevation occurred in 55 (12.8%) patients. Bleeding was observed in 15 (3.5%) patients, 10 of whom had elevated INR levels. Of these, all were treated with continuous-infusion 5-Fluorouracil (5-FU)-based regimens.
Conclusion: Minidose warfarin can protect from clinical thrombosis, but can induce an alteration in INR values and/or haemorrhagic symptoms in patients being treated with 5-FU-based regimens.