MPN vs. Leukemia
- Myeloproliferative neoplasms (MPNs) are a group of rare disorders that affect the bone marrow leading to abnormal cell growth that can lead to an increase in the number of red blood cells, white blood cells, or platelets in the blood.
- Leukemia is a form of cancer that affects the bone marrow and blood leading to uncontrolled and abnormal growth of white blood cells.
- The major difference between myeloproliferative disorders (MPN) and leukemias is the kind of cells being produced. In the case of myeloproliferative disorders (MPNs), affected cells are 'mature' cells but produced in an abnormal inordinate amount. As for leukemia, they're 'immature' cells from the bone marrow.
Although these conditions are still incurable, when caught early they can significantly improve the quality of life, and treatment response and prolong cancer remission for patients. At the very least, prevent a worse prognosis or secondary fatal conditions.
What are Myeloproliferative Neoplasms (MPNs)?
Read More- Polycythemia vera (PV) affecting red blood cells and increasing their number. Red blood cells are the cells that carry oxygen among other vital functions for the body.
- Essential thrombocytopenia (ET) affecting platelets and increasing their number. Platelets are the cells that function in clotting and controlling bleeding.
- Primary myelofibrosis (PMF) causing abnormalities in various white blood cell types that present with increased production of these cells in the early stages but then proceed to decrease significantly as a result of fibrotic tissue forming in the bone marrow preventing cells production. This is considered the most aggressive type of myeloproliferative neoplasms.
- Chronic myeloid leukemia (CML), also known as chronic myelogenous leukemia is a type of blood cancer that affects the production of granulocytes (a kind of white blood cell) from the bone marrow. Myeloproliferative neoplasms which cause chronic myeloid leukemia (MPN-CML) are characterized by the presence of the BCR-ABL fusion gene.
- Chronic neutrophilic leukemia (CNL) is a type of clonal disorder producing abnormal neutrophils (a type of white blood cells).
- Chronic eosinophilic leukemia (CEL) is a type of clonal disorder producing abnormal eosinophils (a type of white blood cells).
The signs and symptoms of each of these will differ according to the type and the patient's overall health, medical history, age, and which phase of the disease they're in.
Dr. Andrienne Phillips, a hematologist and medical oncologist at Weill-Cornell/New York Presbyterian Hospital, says "Symptoms of MPNs really depend on if you're diagnosed early in the course of the MPN or later in the course of the MPN".
What is Leukemia?
Leukemia is a form of cancer that affects the bone marrow and blood leading to uncontrolled and abnormal growth of white blood cells. Leukemia is classified into acute or chronic depending on the state of the affected cells and whether the higher percentage is for the immature cells (like stem cells in the bone marrow) or the mature cells (like white blood cells circulating in the body).
Another classification for leukemia that depends on the type of affected cells in the bone marrow includes myeloid leukemia (which starts in early myeloid cells, red blood cells, or cells that make platelets) or lymphocytic leukemia (which starts in the cells that form lymphocytes).
Despite overlapping in categories with MPN, below is a list of the leukemia types, these include the following:
- Acute myeloid (or myelogenous) leukemia (AML) affects immature cells in the bone marrow white blood cells that don't turn into lymphocytes (from a myeloid lineage)
- Chronic myeloid (or myelogenous) leukemia (CML) affects white blood cells in the bone marrow that don't turn into lymphocytes but takes a longer time (acute myeloid leukemia is more serious and aggressive than chronic myeloid leukemia)
- Acute lymphocytic (or lymphoblastic) leukemia (ALL) develops from early immature lymphocytes (a type of white blood cell)
- Chronic lymphocytic leukemia (CLL) also affects lymphocytes in the bone marrow but takes a longer time (acute lymphocytic leukemia is more serious and aggressive than chronic lymphocytic leukemia)
Although the chronic form of the disease is less aggressive, it takes more time to treat than the acute form of the disease.
The signs and symptoms of each of these will differ according to the type and the patient's overall health, medical history, age, and which phase of the disease they're in.
Myeloproliferative Neoplasms vs. Leukemia Differences
The major difference between myeloproliferative disorders (MPN) and leukemias is the kind of cells being produced. In the case of myeloproliferative disorders (MPNs), affected cells are 'mature' cells but produced in an abnormal inordinate amount. As for leukemia, they're 'immature' cells from the bone marrow.
Can Myeloproliferative Neoplasms (MPN) transform into Leukemia?
Yes, myeloproliferative neoplasms can turn into leukemia in some cases this process is called leukemic transformation, where the fairly dormant, slow-growing MPN neoplasms change into a more aggressive form leading to a worse prognosis for patients.
Generally, when MPNs transform, they turn into secondary acute myeloid leukemia (AML). The subtle difference between primary and secondary acute myeloid leukemia is that secondary acute myeloid leukemia develops after a previous disorder (MPN disorders) as for primary acute myeloid leukemia, develops initially on its own before any causes. The risk for disease transformation is influenced by disease-related factors such as genetic mutations (CALR).
Aside from leukemic transformation, myeloproliferative neoplasms can also transform into other types of MPNs as well. For instance, there have been reports of patients who have polycythemia vera (PV) and essential thrombocythemia that turn into secondary myelofibrosis (MF).
Even though there are no clear causes as to why some MPN patients experience leukemic transformation, it's believed that certain internal and external risk factors can put some patients at a higher risk than others. Thus, doctors usually classify their patients according to their risk and monitor those with high-risk factors for transformation.
What are the Risk Factors for MPN-Leukemic Transformation?
Risk factors that increase the chances for leukemic transformation after myeloproliferative neoplasms are classified depending on the type of MPN that a patient has, these include the following:
Polycythemia Vera
- Old age (older than 60 years old)
- Leukocytosis (high white blood cell count)
- History of chemo and radiotherapy
- Gene mutations (especially in the IDH2 and SRSF2)
- Abnormal or complex karyotype where the chromosomes are too much or too little
Essential Thrombocythemia
- Elderly patients
- Anemia (reduced levels of red blood cells)
- Leukocytosis (increased white blood cell count)
- Thrombocytosis (increased platelet count)
- Gene mutations (especially in TP53 and EZH2)
Primary Myelofibrosis
- Old age (older than 70 years old)
- Males
- Increased number of blast cells in the blood
- Severe symptoms of weight loss, sweating at night, and fever
- Anemia (reduced levels of red blood cells)
- Gene mutations (especially IDH2, RUNX1, and SRSF2)
Unfortunately, there's no way to prevent leukemic transformation. However, knowing the previous risk factors can help doctors continuously monitor their patients to intervene with a suitable treatment strategy in the early stages so that patients may stay in remission and achieve the best treatment response results.
So, if you have myeloproliferative neoplasms, it's imperative to maintain your routine checkups with your doctor to stay ahead of secondary acute myeloid leukemia (AML) transformation.
The Bottom Line
Receiving a diagnosis of either myeloproliferative neoplasms disorder or leukemia can be life-changing. Make sure to share all your concerns with your doctor and discuss your treatment options to get the support you need. Remember, early diagnosis and consistent monitoring are the keys to the best management plan.
Questions to Ask your Doctor
- What type of myeloproliferative neoplasm do I have?
- What tests need to be performed to diagnose my condition?
- What treatment options are available for me?
- Am I at high risk for Leukemic transformation?
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