Targeted Treatments for Myeloproliferative Neoplasms - Episode 2
Broad perspective on diagnosis of the myeloproliferative neoplasms via optimal workup and molecular testing.
Pankit Vachhani, MD: Dr Komrojki, when we talk about MPNs and diagnosis, if you can take us through how the usual workup for MPN happens, what tests are sent, and what is the role of biomarkers in MPN right now for prognosis, and maybe even treatment?
Rami S. Komrojki, MD: Thank you. Depending on what you mentioned just now, the pattern of presentation, as you said, for those patients are either symptoms related to constitutional symptoms, splenomegaly, cytopenias, are sometimes the first presentation of those diseases are thrombotic events, less commonly, manifestations of leukocytosis, sometimes even hyperuricemia. And another avenue nowadays we see is those annual CBC or blood counts checked by the primary care physicians where they pick up an abnormality before the patients are diagnosed or symptomatic. And, obviously, with the discoveries about the phenotype driver mutations, those have become integrated into the diagnosis of patients with myeloproliferative neoplasms. Because as you described, the presentation is not unique to patients with MPN and this could be overlapping with lymphomas, connective tissue diseases, other myeloid diseases. The first step, usually, is to evaluate the blood count, most of the patients eventually will need a bone marrow aspiration biopsy to establish the diagnosis, although in some cases of MPNs we can make the diagnosis by peripheral blood and some of the molecular testing. Historically, the challenge was also to distinguish some of those diseases from reactive processes,essential thrombocythemia, for example, thrombocytosis can be secondary. Erythrocytosis, a list of secondary causes as you well know. And the integration of molecular testing helps us objectively to define that this is a primary bone marrow process. Nowadays, most of the heme-path labs would offer those panels that will include at least the phenotype driver mutations, the JAK2, the MPL, and that their presence can help establish that this is a primary process. Each of those diseases have obviously got diagnostic criteria, no primary, secondary, or major or minor. Most of them nowadays integrate the presence of a clonal marker in establishing the diagnosis. I always emphasize that it's important to spend some time assuring the diagnosis and getting all that information, first the diagnostic information and then the prognostic information because that's important before any treatment. I can't emphasize how many diseases could mimic patients with myeloproliferative diseases, even within the myeloproliferative neoplasms, CML can present with high platelet count alone, can present sometimes with some fibrosis. I've seen several patients have fibrosis and their underlying disease was hairy cell leukemia or lymphoma, or connective tissue disease. We've seen several consults for the concern of polycythemia vera, and it's related to some medications that the patients are on. It's important obviously, to get a blood count, get the chemistries, keep uric acid in mind because many of those patients will have hyperuricemia, get molecular testing, and in many cases, a bone marrow aspirate and biopsy is needed. One could say that in essential thrombocythemia maybe or in P. vera with certain criteria you can make the diagnosis without the bone marrow, but I tend to get a bone marrow at baseline because down the road also if the disease course changes, I want to have a baseline that I would compare to. And many argue that the bone marrow at diagnosis have also some markers that will help us to predict the prognosis of the disease.
Transcript edited for clarity.