PARP inhibitors-associated thrombosis in patients with ovarian cancer: a study of the Spanish Society of Medical Oncology (SEOM) thrombosis and cancer group.

To determine the real-world incidence and predictive factors for venous and arterial thromboembolic events (VTE/AT) in ovarian cancer patients treated with poly-(ADP-ribose) polymerase inhibitors (iPARP). A multicenter retrospective study involving 329 ovarian cancer patients who initiated iPARP treatment between January 2015 and December 2022. The primary outcome was the incidence of VTE/AT. Secondary outcomes included predictive factors for thrombosis and the impact of thrombosis on overall survival (OS). Data were analyzed using logistic regression and Kaplan-Meier survival analysis. The incidence of VTE/AT was 4.9% (16/329). BRCA2 mutations were significantly more prevalent among patients who developed VTE/AT (56.3% vs. 19.2%; p < 0.001). Combined treatment with bevacizumab was significantly associated with a decreased risk of thrombosis (OR: 0.262; 95% CI: 0.095-0.724; p = 0.010). No statistically significant differences were observed in the median OS between patients who experienced VTE/ATE (63 months) and those who did not (47 months), with a p value of 0.876. BRCA2 mutations could be a significant predictor for VTE/AT among ovarian cancer patients treated with iPARP. Concomitant treatment with bevacizumab may offer protection against thrombotic events, although a concomitant bias cannot be ruled out. These findings may be of interest when designing future clinical trials in the field of thromboprophylaxis.