Myelodysplastic syndrome (MDS) (synonyms: Myelodysplasia; ICD-10-GM D 46.9: Myelodysplastic syndrome, unspecified) represents a group of heterogeneous (discordant) diseases of the bone marrow (stem cell diseases). The syndrome is associated with a disorder of hematopoiesis (blood formation), that is, there are qualitative and quantitative changes in hematopoiesis and peripheral cytopenia (decreased number of cells in the blood). Dysplastic (malformed) bone marrow and blood cells with an increased proportion of blasts (precursors or young, not yet finally differentiated cells) are found. From the stem cells of the bone marrow, erythrocytes (red blood cells), leukocytes (white blood cells classified as granulocytes, monocytes, lymphocytes) as well as thrombocytes (blood platelets) develop in healthy individuals through differentiation and maturation. According to the cause, myelodysplastic syndrome can be classified into the following forms:
- Primary myelodysplastic syndrome (>90%).
- Without identifiable cause
- Secondary myelodysplastic syndrome (<10%).
- Therapy-associated myelodysplastic syndrome.
- After previous cytostatic therapy (synonym: chemotherapy) – alkylants, topoisomerase II inhibitors, cisplatin, fludarabine, azathioprine.
- After radiatio (radiotherapy)
- After combined radiochemotherapy (RCTX; v. a. Alkylanzien in combination with radiation therapy).
- After radioiodine therapy
- Triggered by long-term exposure (10-20 years) to toxic (poisonous) substances such as benzenes and also certain solvents – particularly affected are gas station workers, painters and varnishers, as well as airport workers (kerosene).
- Therapy-associated myelodysplastic syndrome.
Sex ratio: women are affected slightly less often than men. Frequency peak: the median age of onset is 75 years. Myelodysplastic syndrome is one of the most common malignant (malignant) bone marrow diseases of older people (in Germany). The incidence (frequency of new cases) is about 4-5 cases per 100,000 inhabitants per year. In the group of people over 80 years of age, the incidence is > 50 diseases per 100,000 inhabitants per year. Course and prognosis: Course and prognosis depend on the type and severity of the myelodysplastic syndrome. As the disease progresses, more and more immature blood cells are produced. Therefore, a transition into prognostically less favorable forms such as acute myeloid leukemia (AML) or chronic myelomonocytic leukemia (CMML) is possible. Approximately 70% of patients die from bleeding, the consequences of AML or from infections. Therefore, it is particularly important for those affected to strengthen their immune system through a healthy diet, physical activity, sufficient rest or sleep, and mental training. This, and above all adequate therapy, can prolong survival. A prospect of cure is only given by stem cell transplantation. The prognosis depends on the extent of cytopenia and is worsened by the following parameters:
- Medullary (affecting the medulla) blast percentage > 5%.
- Presence of complex chromosomal aberrations (deviations).
- Elevated lactate dehydrogenase (LDH)
- Higher age
- Comorbidities (concomitant diseases)
- Reduced general condition of the patient
Transfusion requirements are also included in the estimation of prognosis. Two validated prognostic systems are used to estimate overall survival and the risk of progression (progressing) to acute myeloid leukemia (AML): the “International Prognostic Scoring System (IPPS)” and the “International Prognostic Scoring System-Revised (IPSS-R).” See “Myelodysplastic Syndrome (MDS)/Subsequent Diseases/Predictive Factors”.
