The one known curative treatment is allogeneic stem cell transplantation, but this approach involves significant risks.

Other treatment options are largely supportive, and do not alter the course of the disorder (with the possible exception of ruxolitinib, as discussed below). These options may include regular folic acid, allopurinol or blood transfusions. Dexamethasone, alpha-interferon and hydroxyurea (also known as hydroxycarbamide) may play a role.

Lenalidomide and thalidomide may be used in its treatment, though peripheral neuropathy is a common troublesome side-effect.

Frequent blood transfusions may also be required. If the patient is diabetic and is taking a sulfonylurea, this should be stopped periodically to rule out drug-induced thrombocytopenia.

Splenectomy is sometimes considered as a treatment option for patients with myelofibrosis in whom massive splenomegaly is contributing to anaemia because of hypersplenism, particularly if they have a heavy requirement for blood transfusions. However, splenectomy in the presence of massive splenomegaly is a high-risk procedure, with a mortality risk as high as 3% in some studies.

In November 2011, the FDA approved ruxolitinib (Jakafi) as a treatment for intermediate or high-risk myelofibrosis. Ruxolitinib serves as an inhibitor of JAK 1 and 2.

The "New England Journal of Medicine" (NEJM) published results from two Phase III studies of ruxolitinib. These data showed that the treatment significantly reduced spleen volume, improved symptoms of myelofibrosis, and was associated with improved overall survival compared to placebo.

While investigational drug therapies exist, no curative drug treatment exists for any of the MPDs. The goal of treatment for ET and PV is prevention of thrombohemorrhagic complications. The goal of treatment for MF is amelioration of anemia, splenomegaly, and other symptoms. Low-dose aspirin is effective in PV and ET. Tyrosine kinase inhibitors like imatinib have improved the prognosis of CML patients to near-normal life expectancy.

Recently, a "JAK2" inhibitor, namely ruxolitinib, has been approved for use in primary myelofibrosis. Trials of these inhibitors are in progress for the treatment of the other myeloproliferative neoplasms.

Treatment of this disorder involves treatment of the underlying cancer.

Hydroxycarbamide and anagrelide are contraindicated during pregnancy and nursing. Essential thrombocytosis can be linked with a three-fold increase in risk of miscarriage. Throughout pregnancy, close monitoring of the mother and fetus is recommended. Low-dose low molecular weight heparin (e.g. enoxaparin) may be used. For life-threatening complications, the platelet count can be reduced rapidly using platelet apheresis, a procedure that removes platelets from the blood and returns the remainder to the patient.

The treatment of CMML remains challenging due to the lack of clinical trials investigating the disease as its own clinical entity. It is often grouped with MDS in clinical trials, and for this reason the treatment of CMML is very similar to that of MDS. Most cases are dealt with as supportive rather than curative because most therapies do not effectively increase survival. Indications for treatment include the presence of B symptoms, symptomatic organ involvement, increasing blood counts, hyperleukocytosis, leukostasis and/or worsening cytopaenias.

Blood transfusions and EPO administration are used to raise haemoglobin levels in cases with anaemia.

Azacitidine is a drug approved by the US Food & Drug Administration (FDA) for the treatment of CMML and by the European Medicines Agency for high risk non-proliferative CMML with 10-19% marrow blasts. It is a cytidine analogue that causes hypomethylation of DNA by inhibition of DNA methyltransferase. Decitabine is a similar drug to azacitidine and is approved by the FDA for treatments of all subtypes of MDS, including CMML. Hydroxyurea is a chemotherapy that is used in the myeloproliferative form of CMML to reduce cell numbers.

Haematopoietic stem cell transplant remains the only curative treatment for CMML. However, due to the late age of onset and presence of other illnesses, this form of treatment is often not possible.

The goals of therapy are to control symptoms, improve quality of life, improve overall survival, and decrease progression to AML.

The IPSS scoring system can help triage patients for more aggressive treatment (i.e. bone marrow transplant) as well as help determine the best timing of this therapy. Supportive care with blood products and hematopoietic growth factors (e.g. erythropoietin) is the mainstay of therapy. The regulatory environment for the use of erythropoietins is evolving, according to a recent US Medicare National coverage determination. No comment on the use of hematopoeitic growth factors for MDS was made in that document though.

Three agents have been approved by the FDA for the treatment of MDS:

1. 5-azacytidine: 21-month median survival

2. Decitabine: Complete response rate reported as high as 43%. A phase I study has shown efficacy in AML when decitabine is combined with valproic acid.

3. Lenalidomide: Effective in reducing red blood cell transfusion requirement in patients with the chromosome 5q deletion subtype of MDS

Chemotherapy with the hypomethylating agents 5-azacytidine and decitabine has been shown to decrease blood transfusion requirements and to retard the progression of MDS to AML. Lenalidomide was approved by the FDA in December 2005 only for use in the 5q- syndrome. In the United States, treatment of MDS with lenalidomide costs about $9,200 per month.

Stem cell transplantation, particularly in younger (i.e. less than 40 years of age) and more severely affected patients, offers the potential for curative therapy. Success of bone marrow transplantation has been found to correlate with severity of MDS as determined by the IPSS score, with patients having a more favorable IPSS score tending to have a more favorable outcome with transplantation.

Untreated, polycythemia vera can be fatal. Research has found that the "1.5-3 years of median survival in the absence of therapy has been extended to at least 10-20 years because of new therapeutic tools."

As the condition cannot be cured, treatment focuses on treating symptoms and reducing thrombotic complications by reducing the erythrocyte levels.

Phlebotomy is one form of treatment, which often may be combined with other therapies. The removal of blood from the body induces iron deficiency, thereby decreasing the haemoglobin / hematocrit level, and reducing the risk of blood clots. Phlebotomy is typically performed to bring their hematocrit (red blood cell percentage) down below 45 for men or 42 for women. It has been observed that phlebotomy also improves cognitive impairment.

Low dose aspirin (75–81 mg daily) is often prescribed. Research has shown that aspirin reduces the risk for various thrombotic complications.

Chemotherapy for polycythemia may be used, either for maintenance, or when the rate of bloodlettings required to maintain normal hematocrit is not acceptable, or when there is significant thrombocytosis or intractable pruritus. This is usually with a "cytoreductive agent" (hydroxyurea, also known as hydroxycarbamide).

The tendency of some practitioners to avoid chemotherapy if possible, especially in young patients, is a result of research indicating possible increased risk of transformation to acute myelogenous leukemia (AML). While hydroxyurea is considered safer in this aspect, there is still some debate about its long-term safety.

In the past, injection of radioactive isotopes (principally phosphorus-32) was used as another means to suppress the bone marrow. Such treatment is now avoided due to a high rate of AML transformation.

Other therapies include interferon injections, and in cases where secondary thrombocytosis (high platelet count) is present, anagrelide may be prescribed.

Bone marrow transplants are rarely undertaken in polycythemia patients; since this condition is non-fatal if treated and monitored, the benefits rarely outweigh the risks involved in such a procedure.

There are indications that with certain genetic markers, erlotinib may be an additional treatment option for this condition.

Selective JAK2 inhibitors are being investigated "in vitro" and in clinical trials.

Iron overload can develop in MDS as a result of the RBC transfusions which are a major part of the supportive care for anemic MDS patients. Although the specific therapies patients receive may alleviate the RBC transfusion need in some cases, many MDS patients may not respond to these treatments, thus may develop iron overload from repeated RBC transfusions.

Patients requiring relatively large numbers of RBC transfusions can experience the adverse effect of chronic iron overload on their liver, heart, and endocrine functions. The resulting organ dysfunction from transfusional iron overload might be a contributor to increased illness and death in early-stage MDS.

For patients requiring many RBC transfusions, serum ferritin levels, number of RBC transfusions received, and associated organ dysfunction (heart, liver, and pancreas) should be monitored to determine iron levels. Monitoring serum ferritin may also be useful, aiming to decrease ferritin levels to .

Currently, two iron chelators are available in the US, deferoxamine for intravenous use and deferasirox for oral use. These options now provide potentially useful drugs for treating this iron overload problem. A third chelating agent is available in Europe, deferiprone for oral use, but not available in the US.

Clinical trials in the MDS are ongoing with iron chelating agents to address the question of whether iron chelation alters the natural history of patients with MDS who are transfusion dependent. Reversal of some of the consequences of iron overload in MDS by iron chelation therapy have been shown.

Both the MDS Foundation and the National Comprehensive Cancer Network MDS Guidelines Panel have recommended that chelation therapy be considered to decrease iron overload in selected MDS patients. Evidence also suggests a potential value exists to iron chelation in patients who will undergo a stem cell transplant.

Although deferasirox is generally well tolerated (other than episodes of gastrointestinal distress and kidney dysfunction in some patients), recently a safety warning by the FDA and Novartis was added to deferasirox treatment guidelines. Following postmarketing use of deferasirox, rare cases of acute kidney failure or liver failure occurred, some resulting in death. Due to this, patients should be closely monitored on deferasirox therapy prior to the start of therapy and regularly thereafter.

Hydroxycarbamide, interferon-α and anagrelide can lower the platelet count. Low-dose aspirin is used to reduce the risk of blood clot formation unless the platelet count is very high, where there is a risk of bleeding from the disease and hence this measure would be counter-productive (as they increase one's risk for bleeds).

The PT1 study compared hydroxyurea plus aspirin to anagrelide plus aspirin as initial therapy for ET. Hydroxyurea treated patients had a lower incidence of arterial thrombosis, lower incidence of severe bleeding and lower incidence of transformation to myelofibrosis, but the risk of venous thrombosis was higher with hydroxycarbamide than with anagrelide. It is unknown whether the results are applicable to all ET patients. In people with symptomatic ET and extremely high platelet counts (exceeding 1 million), plateletpheresis can be used to remove platelets from the blood to reduce the risk of thrombosis.

There have been few individual epidemiological studies of CMML, due to the difficulty in the disease classification. CMML has an estimated incidence of less than 1 per 100,000 persons per year.

The median age of diagnosis is 65–75. CMML has a propensity for males rather than females, at a ratio of 1.5–3:1.

The myeloproliferative neoplasms (MPNs), previously myeloproliferative diseases (MPDs), are a group of diseases of the bone marrow in which excess cells are produced. They are related to, and may evolve into, myelodysplastic syndrome and acute myeloid leukemia, although the myeloproliferative diseases on the whole have a much better prognosis than these conditions. The concept of myeloproliferative disease was first proposed in 1951 by the hematologist William Dameshek. In the most recent World Health Organization classification of hematologic malignancies, this group of diseases was renamed from "myeloproliferative diseases" to "myeloproliferative neoplasms". This reflects the underlying clonal genetic changes that are a salient feature of this group of disease.

The increased numbers of blood cells may not cause any symptoms, but a number of medical problems or symptoms may occur. The risk of thrombosis is increased in some types of MPN.

JMML accounts for 1-2% of childhood leukemias each year; in the United States, an estimated 25-50 new cases are diagnosed each year, which also equates to about 3 cases per million children. There is no known environmental cause for JMML. Since about 10% of patients are diagnosed before 3 months of age, it is thought that JMML is a congenital condition in these infants

Radiation to the spleen does not generally result in a decrease in spleen size or reduction of platelet transfusion requirement.

Treatment for erythroleukemia generally follows that for other types of AML, not otherwise specified. It consists of chemotherapy, frequently consisting of

cytarabine, daunorubicin, and idarubicin. It can also involve bone marrow transplantation.

Often, no treatment is required or necessary for reactive thrombocytosis. In cases of reactive thrombocytosis of more than 1,000x10/L, it may be considered to administer daily low dose aspirin (such as 65 mg) to minimize the risk of stroke or thrombosis.

However, in primary thrombocytosis, if platelet counts are over 750,000 or 1,000,000, and especially if there are other risk factors for thrombosis, treatment may be needed. Selective use of aspirin at low doses is thought to be protective. Extremely high platelet counts in primary thrombocytosis can be treated with hydroxyurea (a cytoreducing agent) or anagrelide (Agrylin).

In Jak-2 positive disorders, ruxolitinib (Jakafi) can be effective.

Myelofibrosis, also known as osteomyelofibrosis, is a relatively rare bone marrow cancer. It is currently classified as a myeloproliferative neoplasm, in which the proliferation of an abnormal clone of hematopoietic stem cells in the bone marrow and other sites results in fibrosis, or the replacement of the marrow with scar tissue.

The term "myelofibrosis" alone usually refers to primary myelofibrosis (PMF), also known as chronic idiopathic myelofibrosis (cIMF); the terms idiopathic and primary mean that in these cases the disease is of unknown or spontaneous origin. This is in contrast with myelofibrosis that develops secondary to polycythemia vera or essential thrombocythaemia. Myelofibrosis is a form of myeloid metaplasia, which refers to a change in cell type in the blood-forming tissue of the bone marrow, and often the two terms are used synonymously. The terms agnogenic myeloid metaplasia and myelofibrosis with myeloid metaplasia (MMM) are also used to refer to primary myelofibrosis.

Leukemia is rarely associated with pregnancy, affecting only about 1 in 10,000 pregnant women. How it is handled depends primarily on the type of leukemia. Acute leukemias normally require prompt, aggressive treatment, despite significant risks of pregnancy loss and birth defects, especially if chemotherapy is given during the developmentally sensitive first trimester.

Acute erythroid leukemia is rare, accounting for only 3–5% of all acute myeloid leukemia cases. One study estimated an occurrence rate of 0.077 cases per 100,000 people each year. 64–70% of people with this condition are male, and most are elderly, with a median age of 65.

Polycythemia vera occurs in all age groups, although the incidence increases with age. One study found the median age at diagnosis to be 60 years, while a Mayo Clinic study in Olmsted County, Minnesota found that the highest incidence was in people aged 70–79 years. The overall incidence in the Minnesota population was 1.9 per 100,000 person-years, and the disease was more common in men than women. A cluster around a toxic site was confirmed in northeast Pennsylvania in 2008.

CML accounts for 8% of all leukaemias in the UK, and around 680 people were diagnosed with the disease in 2011.

This is a rare disease, with less than 100 cases reported. Of these cases, an equal male:female ratio was observed,

with cases typically seen in older adults.

Myelophthisis can occur in the setting of chronic myeloproliferative disease (e.g. myelofibrosis), leukemia, lymphoma, and metastatic carcinoma or myeloma. It is common in people who have chronic idiopathic myelofibrosis. It has been linked to small-cell lung cancer, breast cancer or prostate cancer that metastasizes to the bone marrow.

Historically, the most common cause of displacement of healthy bone marrow was tuberculosis.

Currently, the most common cause is displacement of bone marrow by metastatic cancer (extramedullary hematopoiesis tends to be modest). Other causes include myeloproliferative disorders (especially late-stage or spent polycythemia vera), granulomatous diseases, and (lipid) storage diseases. Myelofibrosis can occur in all of these.

Factors that may contribute to decreased RBC production include a decreased quantity of functioning hematopoietic tissue, disordered metabolism related to the underlying disorder, and, in some cases, erythrophagocytosis.

Before the advent of tyrosine kinase inhibitors, the median survival time for CML patients had been about 3–5 years from time of diagnosis.

With the use of tyrosine kinase inhibitors, survival rates have improved dramatically. A 2006 followup of 553 patients using imatinib (Gleevec) found an overall survival rate of 89% after five years.

A 2011 followup of 832 patients using imatinib who achieved a stable cytogenetic response found an overall survival rate of 95.2% after 8 years, which is similar to the rate in the general population. Fewer than 1% of patients died because of leukemia progression.

If treatment has been successful ("complete" or "partial remission"), a person is generally followed up at regular intervals to detect recurrence and monitor for "secondary malignancy" (an uncommon side-effect of some chemotherapy and radiotherapy regimens—the appearance of another form of cancer). In the follow-up, which should be done at pre-determined regular intervals, general anamnesis is combined with complete blood count and determination of lactate dehydrogenase or thymidine kinase in serum.

Myelodysplastic–myeloproliferative diseases are a category of hematological malignancies disorders created by the World Health Organization which have characteristics of both myelodysplastic and myeloproliferative conditions.

When a hematological malignancy is characterised by normal differentiation of cells of myeloid cell line, it is referred to as myeloproliferative. On the other hand, when there is abnormal differentiation of cells of myeloid cell line, it is referred to as myelodysplastic.