Relevance of recurrent venous thromboembolism according to location of metastasis in patients with cancer-associated thrombosis. A cohort study.

BACKGROUND

Risk of VTE recurrence (VTEr) in patients with cancer-associated thrombosis (CAT) is high. Cancer-related risk factors for VTEr have been studied, but information about the importance of location of metastasis is scarce.

OBJECTIVES

1. Evaluate rate of VTEr in CAT patients according to location of metastasis, and 2) Identify variables associated to VTEr during long-term follow-up.

METHODS

A retrospective, single-center, non-interventional study of consecutives patients with CAT conducted between 2007 and 2022. Haematological neoplasms were excluded.

RESULTS

Among 1248 patients with CAT (age 64.1 ± 12.8 years; 48.2 % female) followed-up for 13.19 months (p25-75, 5.6-26.9) there were 141 VTEr. The rate of VTE recurrence in patients without and with metastasis were 4.72 per 100 patient-years (95%CI: 3.66-6) and 10.05 per 100 patient-years (95 % CI: 7.89-12.61), respectively. The metastases locations associated with VTEr, compared to those without metastasis, were lung (rate ratio [RR]: 2.21; 95 % CI: 1.42-3.43), liver (RR: 2.02; 95%CI: 1.26-3.24), pancreas (RR: 6.21; 95 % CI: 1.52-25.35), pleura (RR: 2.93; 95%CI: 1.58-5.41), bone (RR: 2.16; 95 % CI: 1.29-3.64) and adrenal (RR: 6.18; 95%CI: 2.97-12.86). Multivariate analysis of variables associated with VTEr beyond 12 months were male sex (hazard ratio [HR] 1.54, 95%CI: 1.08-2.19), ECOG performance status >1 (HR 1.74, 95%CI: 1.03-2.94), metastasis in 1-2 locations (HR 2.38, 95%CI: 1.68-3.37) and metastasis in >2 locations (HR 3.88, 95%CI: 1.68-8.98).

CONCLUSIONS

The rate of VTEr differs according to the location of metastasis. We identified variables related to VTEr during long-term follow-up which may help clinicians decide whether to continue anticoagulation.