Douglas Tremblay, Amica Kurniati Ko, Pavlina Chrysafi, Joan How, Rebecca L Zon, Damon E Houghton, Atefeh Ghorbanzadeh, Dahniel Sastow, Sai Swetha Alladi, Maria Georgen, Abishta Prabhu, Vrushali Pachpande, Sai Sudha Valisekka, Balkrishna N Jahagirdar, Sargam Kapoor, Andrew Peseski, Radhika Gangaraju, Ruchi Desai, Guoliang Zheng, Shreyash Dalmia, Vinai Chander Bhagirath, Alejandro Godoy, Alessandra Iurlo, Daniele Cattaneo, Paola Guglielmelli, Alessandro M Vannucchi, Valentina Boldrini, Valerio De Stefano, Silvia Betti, Elena Rossi, Walter Ageno, Jonathan Berry, Margherita Maffioli, Mukul Aggarwal, Amiya Ranjan Nayak, Rishi Dhawan, Thita Chiasakul, Kristen Sanfilippo, Gabriela S Hobbs, John O Mascarenhas, Ronald Hoffman, Lisa Baumann Kreuziger, Rushad D Patell, Joan D Beckman, Mandy N Lauw
Myeloproliferative neoplasm (MPN) patients are at risk of splanchnic vein thromboses (SVT). Prior studies have failed to demonstrate a benefit of hydroxyurea therapy in preventing recurrent thrombosis after SVT, but are limited by small sample sizes and inability to account for starting, stopping, or switching of cytoreductive therapies. To better assess the impact of cytoreductive therapy on thrombosis recurrence, we performed a retrospective cohort study of MPN-SVT patients from the international GASTRO-MPN Consortium, treating cytoreductive therapy as a time-dependent covariate. We identified 757 patients, of which 43% were treated with cytoreductive therapy. During a median follow-up of 7.4 years, 256 patients (34%) had thrombosis recurrence; 145 (19%) had SVT extension/recurrence/TIPS thrombosis, 138 (18%) an thrombosis recurrence outside the splanchnic bed (74% were venous). Additionally, 262 patients (35%) experienced clinically relevant bleeding and 170 (22%) died. After adjusting for age, sex, prior thrombosis, timing of MPN diagnosis relative to SVT, anticoagulation initiation within 30 days of SVT diagnosis, MPN type, JAK2 status, other cancers and cirrhosis, cytoreductive therapy was associated with a decreased risk of recurrent thrombosis (HR 0.67 95%CI 0.50-0.89, p=0.01). This was driven by a lower risk of SVT extension/recurrence (HR 0.62 95%CI 0.42-0.90, p=0.01) but not by extra-splanchnic thrombosis recurrence (HR 0.97 95%CI 0.72-1.30, p=0.82). In a subgroup of patients without erythrocytosis/thrombocytosis at initial SVT (n=275), cytoreductive therapy was associated with a HR 0.65 (95%CI 0.40-1.07, p=0.09) for recurrent thrombosis. These data support the use of cytoreductive therapy in MPN-SVT patients to prevent recurrent thrombosis, particularly SVT extension/recurrence.