Special issues in myeloproliferative neoplasms

Management of classical Philadelphia chromosome-negative myeloproliferative neoplasms in Asia: consensus of the Asian Myeloid Working Group

Myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal hematopoietic stem cell disorders characterized clinically by the proliferation of one or more hematopoietic lineage(s). The classical Philadelphia-chromosome (Ph)-negative MPNs include polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The Asian Myeloid Working Group (AMWG) comprises representatives from fifteen Asian centers experienced in the management of MPN. This consensus from the AMWG aims to review the current evidence in the risk stratification and treatment of Ph-negative MPN, to identify management gaps for future improvement, and to offer pragmatic approaches for treatment commensurate with different levels of resources, drug availabilities and reimbursement policies in its constituent regions. The management of MPN should be patient-specific and based on accurate diagnostic and prognostic tools. In patients with PV, ET and early/prefibrotic PMF, symptoms and risk stratification will guide the need for early cytoreduction. In younger patients requiring cytoreduction and in those experiencing resistance or intolerance to hydroxyurea, recombinant interferon-α preparations (pegylated interferon-α 2A or ropeginterferon-α 2b) should be considered. In myelofibrosis, continuous risk assessment and symptom burden assessment are essential in guiding treatment selection. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) in MF should always be based on accurate risk stratification for disease-risk and post-HSCT outcome. Management of classical Ph-negative MPN entails accurate diagnosis, cytogenetic and molecular evaluation, risk stratification, and treatment strategies that are outcome-oriented (curative, disease modification, improvement of quality-of-life).

Haematological malignancies in pregnancy: An overview with an emphasis on thrombotic risks

With increase of maternal age, the incidence of haematological malignancies during pregnancy is rising and posing diagnostic and treatment challenges. Lymphoma is the fourth most common malignancy diagnosed in pregnancy; Hodgkin lymphoma is more frequent in pregnant women than non-Hodgkin lymphoma (NHL). The proportion of highly aggressive lymphomas in pregnant women is significantly higher than in non-pregnant women of reproductive age. Reproductive organ involvement is observed in almost half of pregnant women with NHL. The association of acute leukaemia and pregnancy is infrequent and it is assumed that pregnancy does not accelerate the disease course. Both cancer and pregnancy induce a procoagulant state which can lead to maternal venous thromboembolism (VTE) and placental occlusion. Pregnancy in woman with myeloproliferative neoplasms (MPN) promotes thrombotic environment, associating with an augmented risk of placental thrombosis, intrauterine growth retardation or loss and maternal thrombotic events.Haematological malignancies during pregnancy often require urgent diagnosis and management and are associated with potential adverse fetal outcomes. Most chemotherapeutic agents are teratogenic and should be avoided during the first trimester. Their use during the second and third trimesters may cause intrauterine growth restriction, premature birth and intrauterine fetal death. All chemotherapeutic drugs should be administered only after a detailed discussion with the patient and with close fetal monitoring. Chemotherapy and biological agents might also augment thrombotic risk. Guidelines for VTE prophylaxis in pregnant women with hematologic malignancies, apart from MPN, are currently unavailable, and therefore, clinical judgment should be made in each case.

A Concise Update on Risk Factors, Therapy, and Outcome of Leukemic Transformation of Myeloproliferative Neoplasms

Myeloproliferative neoplasms (MPN) in chronic phase that evolve into blast phase (BP) hold a dismal prognosis and represent an urgent unmet clinical need. The mutational landscape of MPN-BP is distinct from de novo acute myeloid leukemia and offers insight into molecular mechanisms contributing to clonal evolution providing potential novel drug targets. A number of retrospective studies have identified patient- and disease-specific variables associated with increased risk of leukemic transformation (LT) of an underlying MPN. Several prognostic models have been developed to identify those MPN patients at highest risk for LT that may warrant early aggressive therapeutic intervention. Acute myeloid leukemia-type induction chemotherapy does not offer a significant survival benefit for MPN-BP unless followed by hematopoietic stem-cell transplantation. Unfortunately, most patients with MPN-BP are not candidates for hematopoietic stem-cell transplantation as a result of advanced age, competing comorbid conditions, or lack of an acceptable donor graft option. JAK2 inhibitor monotherapy is effective in reducing splenomegaly and symptom burden in the majority of treated patients with myelofibrosis, but LT can still occur. High-dose JAK2 inhibitor monotherapy appears tolerable but only modestly active in the treatment of MPN-BP. Current JAK2 inhibitor-based combination therapy approaches are supported by preclinical investigation and are currently being tested in multicenter clinical trials.

Hematologic malignancies during pregnancy: A review

Malignancy is the second most common cause of mortality in the reproductive period and it complicates up to one out of every 1000 pregnancies. When cancer is diagnosed during pregnancy, the management approach must take into consideration both the mother and her fetus. Hematologic cancers diagnosed in pregnancy are not common, resulting in paucity of randomized controlled trials. Diagnosis of such malignancies may be missed or delayed, as their symptoms are similar to those encountered during normal pregnancy. Also, many imaging studies may be hazardous during pregnancy. Management of these malignancies during pregnancy induces many treatment-related risks for mother and baby and should consider patient's preferences for pregnancy continuation. In this article, hematologic malignancies diagnosed in pregnant patients including acute leukemias, chronic myeloid leukemia, lymphomas, multiple myeloma and myeloproliferative neoplasms, will be reviewed, including diagnostic and management strategies and their impact on the pregnant patient and the developing fetus.

Myeloproliferative neoplasms working group consensus recommendations for diagnosis and management of primary myelofibrosis, polycythemia vera, and essential thrombocythemia

According to the 2008 revision of the World Health Organization (WHO) classification of myeloid malignancies, philadelphia chromosome (Ph)-negative myeloproliferative neoplasms (MPNs) include clonal, hematologic disorders such as polycythemia vera, primary myelofibrosis, and essential thrombocythemia.

Recent years have witnessed major advances in the understanding of the molecular pathophysiology of these rare subgroups of chronic, myeloproliferative disorders. Identification of somatic mutations in genes associated with pathogenesis and evolution of these myeloproliferative conditions (Janus Kinase 2; myeloproliferative leukemia virus gene; calreticulin) led to substantial changes in the international guidelines for diagnosis and treatment of Ph-negative MPN during the last few years.

The MPN-Working Group (MPN-WG), a panel of hematologists with expertise in MPN diagnosis and treatment from various parts of India, examined applicability of this latest clinical and scientific evidence in the context of hematology practice in India.

This manuscript summarizes the consensus recommendations formulated by the MPN-WG that can be followed as a guideline for management of patients with Ph-negative MPN in the context of clinical practice in India.

Pathogenesis and management of acute myeloid leukemia that has evolved from a myeloproliferative neoplasm

PURPOSE OF REVIEW

The myeloproliferative neoplasms (MPNs), including essential thrombocythemia, polycythemia vera and primary myelofibrosis (PMF), are a heterogeneous group of myeloid-derived chronic haematopoietic malignancies. Frequent clinical consequences of these diseases include not only an increased risk of thrombosis but also leukemic transformation, which carries a particularly poor prognosis. Here, we discuss the recent identification of risk factors for leukemic transformation, elucidate mechanisms contributing to leukemic transformation, as well as highlight the development of new treatment strategies.

RECENT FINDINGS

Significant progress in the understanding of the biology of MPNs has been made in recent years, particularly with the discovery that mutations in the JAK-STAT signaling pathway cause unregulated activation. These genetic insights have been extended to leukemic transformation and have revealed a host of genetic alterations that occur at the time of transformation, and that may identify patients at risk for leukemic transformation. Such studies have demonstrated that acute myeloid leukemia (AML) evolved from a chronic phase MPN is distinct from de-novo AML both genetically and clinically given its resistance to conventional antileukemic therapy.

SUMMARY

Leukemic transformation of an MPN remains a significant clinical challenge. Recent advances in the understanding of the molecular events that contribute to the development of leukemic transformation will need to be utilized in order to produce rational therapeutic approaches for this largely fatal disease.

A case of Philadelphia chromosome positive myeloproliferative neoplasm in a pregnant woman with unusual primary myelofibrosis features

Myeloproliferative neoplasms (MPNs) are traditionally separated into BCR-ABL-positive chronic myeloid leukemia (CML), and BCR-ABL-negative MPNs including primary myelofibrosis (PMF), essential thrombocythemia (ET), and so forth. One of the diagnostic requirements for PMF and ET is the absence of the Philadelphia chromosome, while its presence is almost universally indicative of CML. However, a diagnostic dilemma arises when Philadelphia chromosome-positive MPNs lack the majority of the typical features seen in CML. Some of these classic CML features include basophilIa, marked leukocytosis, neutrophils left-shift with myelocytes bulge, and "dwarf" megakaryocytes. Presented here is a case of a 32-year-old pregnant patient who did not have typical morphologic findings for CML, and yet the Philadelphia chromosome was positive. The patient demonstrated some pathologic features that are commonly presented in PMF that included bone marrow reticulin fibrosis, leukoerythroblastosis, splenomegaly, and increased serum lactate dehydrogenase.

Haematological cancers in pregnancy

Haematological cancer in pregnancy, although rare, poses a substantial risk to both mother and fetus. Hodgkin's lymphoma is the most common, followed by non-Hodgkin lymphoma and acute leukaemia. Diagnosis of haematological cancers is challenged by an overlap of the disease and gestation-related symptoms and limitations of imaging studies in pregnancy. Data for safety and effectiveness of therapy are scarce and mostly retrospective. This report provides updated guidance for management, focusing on chemotherapy and biological agents. The primary goal of treatment is to preserve the mother's health; hence, pregnancy termination is often advisable at early stages, allowing delivery of adequate therapy. However, at later gestational stages treatment is often feasible. Pregnancy-related hypercoagulability, augmented by cancer, often necessitates thromboprophylaxis. The consequences and complex management of haematological cancer during pregnancy emphasise the need for collaborative research, focusing on basic mechanisms of disease and prospective epidemiological studies.