The presence of a factor V Leiden (FVL) mutation or non-O blood type were associated with an increased risk of venous thromboembolism (VTE) among patients with thrombophilia and cancer who were receiving chemotherapy, according to study results published in the Journal of Thrombosis and Haemostasis. Prophylactic use of anticoagulation mitigated the risk associated with FVL mutation or non-O blood type.

This post hoc analysis of patients from the AVERT trial evaluated data from 447 patients with inherited thrombophilia who also had ambulatory cancer that put them at moderate-to-high risk of VTE. All patients were undergoing chemotherapy.

The median age of the cohort at baseline was 62 and 43% of patients were male. There were 36.9% and 50.7% of patients with or without VTE taking apixaban. There were 4.5% of patients harboring a FVL mutation and 60.4% with a non-O blood type.

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There were 39 patients who developed VTE and 39 who experienced bleeding. An FVL mutation was significantly associated with higher odds of VTE (odds ratio [OR], 5.24; 95% CI, 1.86-14.70; P =.0017). A non-O blood type was also associated with an increased risk of developing VTE (OR, 2.72; 95% CI, 1.22-6.08; P =.0144).

The presence of mutation sin FII, FXI, fibrinogen gamma, serpin family A member 10, and FV at K858R were not associated with an increased risk of VTE. None of the mutations evaluated, including in FVL, and none of the ABO blood types were associated with a risk of bleeding.

The risk of VTE was completely mitigated among patients with an FVL mutation who received prophylactic anticoagulation. The risk was also mitigated among patients with a non-O blood type, but to a lesser extent.

“Our study indicated that an FVL mutation and non-O blood types are associated with an increased risk of VTE in intermediate to high-risk ambulatory cancer patients receiving chemotherapy, and these patients benefitted from prophylactic anticoagulation with a low risk of bleeding,” the authors concluded in their report.

Disclosures: The study was supported in part by Bristol Myers Squibb and Pfizer. Please see the original reference for a full list of disclosures.

Roy DC, Wang T-F, Carrier M, et al. Thrombophilia gene mutations predict venous thromboembolism in ambulatory cancer patients receiving chemotherapy. J Thromb Haemost. Published online August 1, 2023. doi: 10.1016/j.jtha.2023.07.017