Choosing between stem cell therapy and drugs in myelofibrosis.

Optimal clinical management of patients with primary myelofibrosis and post-essential thrombocythemia/polycythemia vera myelofibrosis is a challenge, given the typically advanced age of presentation and variability of the disease course and prognosis. Current medical therapeutic options have not demonstrated an impact on the disease course, which exceeds the palliation of disease-related extramedullary hematopoiesis and alleviation of cytopenias. In contrast, allogeneic stem cell transplantation (SCT) can lead to 'cure' but is limited due to patient's age or comorbidities. Currently, in patients, who are reasonable candidates, SCT (frequently with a reduced intensity conditioning regimen) is employed for intermediate- to high-risk disease. Current pharmaco-medical therapy is used as a bridge to transplant, or instead of transplant in poor transplant candidates. Pathogenetic insights, especially the discovery of the Janus kinase (JAK)2(V617F) mutation, have ushered in a host of new potential therapeutic agents that may augment the role of medical therapy. Similarly, the boundaries of transplantation continue to alter with strategies that decrease conditioning-related toxicity, improved antimicrobial prophylaxis and decreased graft-versus-host disease. The potential for continued improvements in both medical and transplant therapy suggests that for the immediate future the optimal choices for an individual patient will remain potentially volatile and present complex decisions.