Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML) are conditions impacting the blood and bone marrow. These disorders arise when the body’s blood-forming cells encounter abnormalities, disrupting the normal production of healthy blood cells.
Understanding Myelodysplastic Syndromes and Acute Myeloid Leukemia
Myelodysplastic Syndromes (MDS) are cancers where abnormal blood-forming cells in the bone marrow lead to insufficient production of healthy blood cells. This results in low levels of one or more blood cell types. These dysplastic cells fail to mature properly and may die prematurely.
Acute Myeloid Leukemia (AML) is a cancer of myeloid blood cells, characterized by the rapid, uncontrolled growth of immature, abnormal cells (myeloblasts or leukemic blasts). These cells accumulate in the bone marrow and blood, preventing the production of normal blood cells. AML is an aggressive cancer that progresses quickly.
MDS can transform into AML when immature blast cells in the bone marrow or blood exceed 20%. About one in three individuals with MDS may experience this. This progression involves the disruption of normal blood stem cell maturation, leading to an overproduction of non-functional cells.
Identifying Symptoms and Diagnostic Methods
Symptoms of MDS and AML arise from the bone marrow’s inability to produce enough healthy blood cells. Patients experience fatigue and shortness of breath due to anemia (low red blood cells). A low platelet count can cause easy bruising, nosebleeds, or petechiae (small red spots under the skin). Decreased functional white blood cells can lead to frequent infections.
Diagnosis begins with blood tests, including a complete blood count (CBC), to reveal abnormal blood cell numbers. If initial tests suggest a problem, a bone marrow aspiration and biopsy are performed. A small sample of bone marrow and bone is collected for microscopic analysis, identifying abnormal cells and assessing maturation.
Genetic and molecular testing plays a role in classifying MDS and AML and guiding treatment. These tests look for specific chromosomal abnormalities (cytogenetics) and gene mutations in blood or bone marrow cells. For instance, mutations in genes like NPM1 and FLT3 are found in AML, while SF3B1 or TP53 can be relevant in MDS. These changes help doctors understand disease behavior and treatment response.
Treatment Approaches
Treatment for Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML) is individualized based on disease type, patient age, health, and progression. For MDS, treatment begins with supportive care to manage symptoms and improve quality of life. This may include blood transfusions for anemia or low platelets, and growth factors to stimulate blood cell production.
For higher-risk MDS or risk of AML progression, lower-intensity therapies are used. These include hypomethylating agents like azacitidine or decitabine, which improve bone marrow function and reduce AML transformation risk. Immunosuppressive therapies, such as lenalidomide, may be considered for specific MDS subtypes, like those with del(5q).
Acute Myeloid Leukemia (AML) treatment involves intensive chemotherapy, often in two phases: induction and consolidation. Induction chemotherapy, using combinations of drugs, aims to achieve remission by destroying leukemic cells. Consolidation chemotherapy then follows to eliminate remaining cancer cells and prevent relapse. For patients not suitable for intensive chemotherapy, lower-intensity options, combined with targeted therapies, are available.
Targeted therapies focus on specific genetic mutations in AML cancer cells. For example, FLT3 inhibitors are used for FLT3 gene mutations, while IDH inhibitors target IDH1 or IDH2 mutations. BCL-2 inhibitors are often combined with chemotherapy for older or less fit patients. Stem cell transplantation offers a potentially curative option for both MDS and AML, involving high-dose chemotherapy to eliminate diseased bone marrow followed by infusion of healthy donor stem cells.
Prognosis and Management
The long-term outlook for individuals with MDS and AML varies, influenced by disease subtype, patient age, overall health, and treatment response. For MDS, risk stratification systems, like the Revised International Prognostic Scoring System (IPSS-R), help predict AML progression and survival. Genetic abnormalities identified during diagnosis also provide prognostic information for both conditions.
Ongoing monitoring and follow-up care are essential after treatment for MDS and AML. This includes regular blood tests and bone marrow evaluations to detect recurrence or progression. Managing potential complications and treatment side effects, such as infections or fatigue, is continuous care. Clinical trials offer access to new treatment options and contribute to advancements in managing these conditions.