Characteristics of patients with myeloproliferative neoplasms with lymphoma, with or without JAK inhibitor therapy

It is well known that patients with cancer may subsequently develop secondary/therapy-related neoplasms, generally exhibiting poorer prognosis than their de novo counterparts.¹ Among patients with myeloproliferative neoplasms (MPN), there may be a higher rate of second malignancies before, concomitant with, or after their MPN diagnosis as compared with the general population^2-9 (Table 1). We recently reported (and others confirmed) the association of lymphoid malignancies coexistent with an MPN diagnosis and found this to be an overall rare phenomenon that did not predict for worse clinical outcomes among MPN patients.¹⁰ The incidence and relative risk of post-MPN lymphoid neoplasms has been evaluated, and a 1.4- to 5-fold higher risk in this population has been identified, regardless of therapy received (Table 1). A recent important report in this area raises the possibility that those patients with MPN treated with a Janus kinase (JAK) inhibitor class of therapies may have a markedly higher rate of development of a subsequent lymphoma than patients who did not receive these therapies.¹¹ Given the paucity of data sets that specifically focus on those patients with MPN treated with a JAK inhibitor subsequently diagnosed with a lymphoma, we sought to determine the characteristics and outcomes of this particular subset of patients in our large patient database.