Potential clinical benefits of warfarin in end‐stage cancers: A retrospective analysis

BACKGROUND AND AIMS: Coagulopathy and thromboembolism are common comorbidities in cancer, and anticoagulants, such as warfarin, are needed in specific situations. This study aimed to determine the clinical relevance of prothrombin time (PT) monitoring and the clinical usefulness of warfarin in patients with malignancy. METHODS: We retrospectively investigated patients with PT lower than 10% treated in our hospital between April 2006 and March 2013. Cases of false coagulopathy, including those due to technical errors during blood sampling, were excluded. The cause of coagulopathy was determined or estimated by physicians. RESULTS: This study included 338 cases comprising 155 females and 183 males with a median age was 68 (0–97) years. Among them, 89 (26.3%) had cancer, and 163 (48.2%) received warfarin at a median dose of 2.23 (0.5–8.0) mg/day. PT prolongation caused by warfarin overdose and malignancy exacerbation were observed in 75 (22.2%) and 64 (18.9%) patients, respectively. The leading reasons for warfarin administration were arterial fibrillation, chronic heart failure, and deep vein thrombosis. Univariate analysis revealed that the overall survival was higher in the warfarin and nononcology groups than in the nonwarfarin and oncology groups (both p < 0.001). In multivariate analysis, survival was significantly decreased in older adults (p = 0.049), those with malignancy (p < 0.001), and those without warfarin therapy (p < 0.001). Early mortality (within 3 days after PT prolongation) was observed in 65 patients and was mostly related to emergent diseases (36.9%, 24/65) and end‐stage malignancy (32.3%, 21/65). CONCLUSION: Patients with malignancy may experience subclinical PT prolongation upon disease progression. Warfarin treatment mitigates panic PT values in patients with malignancy. Conversely, those not treated with warfarin have poor survival, suggesting that coagulopathy without warfarin treatment can lead to death. Warfarin enhances hemostatic conditions, thereby preventing malignancy‐related lethal hemorrhagic or thromboembolic events.