MYELODYSPLASTIC SYNDROME (MDS)

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Myelodysplastic Syndrome (MDS) is a group of disorders caused by poorly formed or dysfunctional blood cells. These conditions, which primarily affect older adults. MDS is a rare group of blood disorders where your bone marrow, the factory that produces blood cells, malfunctions. This malfunctioning leads to a shortage of healthy blood cells, affecting your body’s ability to fight infection, carry oxygen, and control bleeding. Some people might refer to it as a bone marrow failure disorder.

The Role of Bone Marrow

Bones not only provide structural support but also house bone marrow, which produces essential blood cells, including:

• Red Blood Cells: Transport oxygen throughout the body.
• White Blood Cells: Crucial for the immune system.
• Platelets: Assist in blood clotting.

In MDS, bone marrow produces insufficient or defective blood cells.

Causes of Myelodysplastic Syndrome

The exact cause of MDS remains unclear. However, several factors contribute to its development:

• Genetic Mutations: Changes in the DNA of blood cells can lead to MDS.
• Radiation and Chemotherapy: Previous cancer treatments can increase the risk of developing MDS.
• Chemical Exposure: Contact with certain chemicals, like benzene, is linked to MDS.
• Inherited Conditions: Some genetic disorders predispose individuals to MDS.

Types of Myelodysplastic Syndromes

MDS encompasses various conditions. Identifying the specific type involves considering several factors:

• Affected Blood Cells: Determining how many types of blood cells are affected. Some forms of MDS impact only one type of blood cell, such as red blood cells, while others affect multiple types.
• Blasts Count: The number of immature blood cells, or “blasts,” in the bone marrow and blood is assessed. These cells have not matured fully and do not function properly.
• Genetic Material: The genetic makeup of the bone marrow cells is examined. In certain types of MDS, part of a chromosome may be missing.

Progression of MDS

The type of MDS you have influences the disease’s progression:

• Risk of Acute Myeloid Leukemia (AML): Some types of MDS have a higher likelihood of developing into AML, a condition where the bone marrow produces an excessive amount of a particular type of white blood cell. Without treatment, AML can progress rapidly.
• Lower Leukemia Risk: Most types of MDS present a much lower risk of transitioning into leukemia.

Factors Influencing MDS Progression

Several factors affect the course of MDS:

• History of Cancer Treatment: MDS that develops following cancer treatment may have different characteristics and progression.
• Blasts Count: The number of blasts in your bone marrow is a crucial factor in determining the severity and potential progression of MDS.

Prevalence

MDS primarily affects older adults, with most diagnoses occurring in individuals over the age of 60. The prevalence is higher in men than women. Although considered rare, the incidence of MDS has been rising, partly due to increased awareness and improved diagnostic techniques.

Symptoms of Myelodysplastic Syndrome

Myelodysplastic syndromes (MDS) often show no early symptoms, making it challenging to detect initially. However, as the disease progresses and affects various blood cells, several warning signs may emerge:

• Constant Tiredness: Persistent fatigue is common due to anemia, which occurs when there are insufficient red blood cells.
• Unusual Bleeding: Increased susceptibility to bleeding can be a sign of MDS.
• Bruising and Red Marks: Easy bruising and the appearance of tiny red spots under the skin (petechiae) are indicators.
• Paleness: A noticeable pallor or pale complexion may develop.
• Shortness of Breath: Experiencing breathlessness during physical activity or exercise can be a symptom.

Risk Factors for Myelodysplastic Syndrome

Each year, approximately 12,000 Americans are diagnosed with MDS. The likelihood of developing MDS increases with age. Other significant risk factors include:

1. Cancer Treatments: Certain chemotherapy or radiation treatments can lead to MDS, sometimes referred to as “treatment-related MDS.” This can occur 1 to 15 years post-treatment, particularly following therapies for acute lymphocytic leukemia, Hodgkin’s disease, or non-Hodgkin’s lymphoma. Drugs associated with an increased risk include:
   • Chlorambucil (Leukeran)
   • Cyclophosphamide
   • Doxorubicin (Adriamycin)
   • Etoposide (Etopophos)
   • Ifosfamide (Ifex)
   • Mechlorethamine (Mustargen)
   • Melphalan (Alkeran)
   • Procarbazine (Matulane)
   • Teniposide
2. Tobacco Use: Smoking elevates the risk of developing MDS.
3. Benzene Exposure: Benzene, a chemical with a sweet smell used in producing plastics, dyes, and detergents, is linked to MDS upon excessive exposure.
4. Inherited Conditions: Certain genetic disorders increase the likelihood of MDS, such as:
   • Down Syndrome: Presence of an extra chromosome leading to various developmental issues.
   • Fanconi Anemia: Affects bone marrow, reducing the production of blood cells.
   • Bloom Syndrome: Characterized by short stature and sensitivity to sunlight.
   • Ataxia Telangiectasia: Impacts nervous and immune systems, causing balance and coordination issues.
   • Shwachman-Diamond Syndrome: Results in low white blood cell counts.
5. Blood Diseases: Individuals with specific blood disorders are at higher risk for MDS, including:
   • Paroxysmal Nocturnal Hemoglobinuria: A severe disorder affecting red and white blood cells, and platelets.
   • Congenital Neutropenia: Characterized by a deficiency of a particular white blood cell type, leading to frequent infections.

Diagnosis

To determine if you have one of the myelodysplastic syndromes, your doctor will review your symptoms and medical history. The diagnostic process typically involves several steps:

1. Physical Exam: The doctor will conduct a thorough physical examination to rule out other possible causes for your symptoms.
2. Blood Test: A blood sample will be taken to count the different types of blood cells.
3. Bone Marrow Sample: A sample of bone marrow will be obtained for analysis. This involves inserting a special needle into your hip bone or breastbone to extract the sample.
4. Cytogenetic Analysis: Cells from the bone marrow will undergo genetic analysis to identify any abnormalities in the chromosomes.
5. Flow Cytometry: Assessing cell characteristics and confirming the diagnosis.

Treatments for Myelodysplastic Syndrome

The treatment plan for myelodysplastic syndromes (MDS) varies based on the type and severity of the condition. Here are the main approaches your doctor might consider:

Watchful Waiting

If your symptoms are mild and your blood counts are stable, your doctor may recommend regular monitoring without immediate treatment. This approach involves routine check-ups to keep an eye on your condition.

Low-Intensity Treatments

For more active management, especially if symptoms start to develop or worsen, your doctor might suggest the following low-intensity treatments:

1. Chemotherapy Drugs: Similar to those used for treating leukemia, these drugs help manage MDS.
2. Immunosuppressive Therapy: This treatment aims to suppress the immune system’s attack on the bone marrow, potentially helping to increase blood cell production.
3. Blood Transfusions: A common and safe procedure to help boost low blood cell counts.
4. Iron Chelation Therapy: Frequent transfusions can lead to excess iron in the blood. This therapy helps reduce iron levels.
5. Growth Factors: These synthetic hormones stimulate the bone marrow to produce more blood cells.

High-Intensity Treatments

In cases where more aggressive treatment is needed, high-intensity options might be considered:

1. Stem Cell Transplant: The only known cure for MDS. The process involves:
   • Chemotherapy or Radiation: These treatments are used to destroy the existing bone marrow cells.
   • Stem Cell Infusion: After the initial treatment, stem cells from a donor are introduced into your body. These can be sourced from bone marrow or blood and will start producing new, healthy blood cells.
2. Combination Chemotherapy: This high-intensity approach uses multiple chemotherapy drugs to aggressively target the disease.

Home Care Tips

Managing MDS at home involves:

• Regular Monitoring: Frequent blood tests to monitor cell counts.
• Healthy Diet: Nutrient-rich foods to support overall health.
• Avoiding Infections: Taking precautions like frequent hand washing and avoiding crowded places.
• Managing Fatigue: Prioritizing rest and avoiding strenuous activities.

Prevention of Myelodysplastic Syndrome

Preventive measures include:

• Avoiding Exposure to Chemicals: Minimizing contact with known carcinogens like benzene.
• Healthy Lifestyle: Maintaining a balanced diet and regular exercise.
• Regular Check-Ups: Especially for individuals with a history of cancer treatments.

When to See a Doctor

Consult a healthcare provider if you experience persistent fatigue, frequent infections, unusual bruising, or other concerning symptoms. Early diagnosis and treatment can significantly improve outcomes.

Outlook and Prognosis

The prognosis for MDS varies widely. Some individuals live for many years with minimal symptoms, while others may progress to acute myeloid leukemia (AML). Advances in treatment have improved the outlook for many patients, making regular medical care and monitoring essential.

Sources

1. American Cancer Society. (2023). Myelodysplastic Syndromes Overview.
2. National Cancer Institute. (2023). Myelodysplastic Syndromes Treatment.
3. Mayo Clinic. (2023). Myelodysplastic Syndromes: Symptoms and Causes.
4. Leukemia & Lymphoma Society. (2023). Understanding Myelodysplastic Syndromes.
5. DeAngelo, D, Myelodysplastic Syndromes: Biology and Treatment, in Hematology: Basic Principles and Practice, Saunders Elsevier, 2013.
6. National Heart Lung and Blood Institute. What is Fanconi Anemia?
7. National Library of Medicine. Shwachman-Diamond Syndrome, Severe Congenital Neutropenia.
8. Ferri’s Netter Patient Advisor. Managing your myelodysplastic syndrome.
9. Nemours (KidsHealth.org). About Down Syndrome.
10. NIH. U.S. National Library of Medicine. Bloom syndrome, Ataxia-telangiectasia, Paroxysmal nocturnal hemoglobinuria, Severe congenital neutropenia.