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Factor V Leiden mutation in patients with breast cancer and a central venous catheter: Relationship with deep vein thrombosis.

8020 Background: Disorders of coagulation are encountered in up to 90% of cancer patients (pts), although only 15% of them develop a localized acute or chronic deep venous thrombosis (DVT) or a disseminated intravascular coagulation. Aim of the study was to assess the influence of the prothrombotic factor V Leiden and G20210A prothrombin mutation on the prevalence of the 1st event of catheter-related deep vein thrombosis in a cohort of pts with locally advanced or metastatic breast cancer during continuous venous insult (infusion of fluorouracil-based chemotherapy).


METHODS
Between 1.1999 and 2.2001, we retrospectively analyzed the incidence of first deep vein thrombosis in 300 consecutive pts with locally advanced or metastatic breast cancer treated in a single institution with a combination of chemotherapy administered continuously through a totally implanted access port. We identified 25 women (study group; cases) with catheter-related deep vein thrombosis. For each we selected two pts (50 pts - controls) for identical chemotherapy, similar age, stage of disease and prognostic features. The prothrombotic factor V Leiden and prothrombin mutation G20210A genotype analyses were performed in all patients who signed a specific informed consent. All samples were blinded.


RESULTS
All 25 cases and 50 frequency-matched controls were evaluated for Factor V Leiden. Five cases and 2 controls were found with the mutation in the factor V Leiden for a frequency of 20% (95% CI= 9%-39%) and 4% (95% CI=1%-14%) respectively. Thus, the frequency of the mutation was significantly higher in the cases than in controls (p=0.04) and a logistic regression analysis, adjusted by age, yielded an odds ratio of 6.1 (95% CI=1.1-34.3; p=0.04). Only one patient (case) was found with the G20210A mutation in the prothrombin gene.


CONCLUSIONS
Factor V Leiden carriers with locally advanced or metastatic breast cancer are at high risk of catheter-related deep vein thrombosis during chemotherapy. Clinicians should be aware of this increased risk and antithrombotic phophylaxis should be considered for these patients. No significant financial relationships to disclose.