Myelodysplastic syndromes (MDS) affect the bone marrow, which then produces too few healthy blood cells. MDS are difficult to qualify owing to their complexity and can evolve into acute myeloid leukemia (AML) if not detected in time.
Bone marrow permanently produces three types of blood cells: red blood cells or erythrocytes (which transport oxygen), white blood cells or leukocytes (which combat infections), and blood platelets (which form clots to stop bleeding).
In patients suffering from myelodysplastic syndromes, bone marrow produces abnormal blood cells. It is also characterized by the accumulation of blasts, cells that have stopped differentiating and therefore do not mature.
Cases increase with age
The number of people diagnosed with a myelodysplastic syndrome each year is not known with certainty. At the global level, it is estimated that there are 87,000 new cases per year(1). In the United States, MDS is estimated to affect between 60,000 and 120,000 people(2).
The majority of myelodysplastic syndromes appear in people over the age of 65, and are more frequent in people over the age of 80 (3). With increased life expectancy, the number of cases diagnosed each year is likely to increase.
The majority of people affected by myelodysplastic syndromes are over the age of 65(3).
Myelodysplastic syndromes are complex diseases
There are several types of myelodysplastic syndromes. Their risks differ depending on how they evolve and the patient profile. There are as many forms of MDSs as there are cases.
Understanding the role of blasts
Everyone has blasts circulating in their blood. In healthy people, bone marrow contains less than 5%. A higher percentage of blasts in the bone marrow is therefore a concern. Myelodysplastic syndromes are broached when the percentage of blasts in the bone marrow exceeds 5%. In this case, immature cells abound and the risk of this condition progressing into acute myeloid leukemia (AML) is higher.
A high level of blasts alone is not sufficient to indicate the presence of a myelodysplastic syndrome. In certain patients with a MDS, blast count does not exceed 5%(4). However, some cells have stopped functioning, leading to a decline in the number of red blood cells or a platelet deficiency.
France’s National Authority for Health (Haute Autorité de Santé, HAS) estimates that 30% of patients suffering from a high-risk myelodysplastic syndrome go on to develop acute myeloid leukemia(5). Their life expectancy drops to less than two years(6).
MDS: Nonspecific symptoms
There are no telltale signs or symptoms that would point to a myelodysplastic syndrome. MDS mainly presents with anemia (decline in red blood cells in the blood), which translates to a pale complexion and chronic fatigue, vertigo and feelings of lightheadedness, and headaches. These symptoms, although common and not specific to anemia, should nevertheless be cause for concern.
Some patients may present with no symptoms.
Quite often, MDS are detected in late stages, when the bone marrow has ceased to produce functional cells. Patients can no longer fight infection (owing to low white blood count) nor stop bleeding (due to platelet deficiency).
How are myelodysplastic syndromes diagnosed?
Anemia can guide diagnosis, but the conditions not specific to MDS. This one condition alone does not allow a precise diagnosis to be made. Elderly patients, in particular, often have several other pathologies, for which treatments can induce anemia.
Therefore, it is a complete blood count (CBC) or a hemogram, that determine whether the number of blood cells is sufficient or excessive. These comprehensive blood tests carried out in laboratories examine the appearance of cells and fine-tunes the diagnosis.
Analyses and complementary tests, such as a puncture or bone marrow biopsy, must also be carried out so that a hematopathologist can confirm the suspected diagnosis(5). Especially since research has led to the discovery of tumoral markers(7) or substances in the body whose levels can indicate the presence of cancer. These markers help hematologist-oncologists to make a prognosis and guide therapeutic decisions.
Suitable treatments, at the right time
A patient suffering from myelodysplastic syndrome runs a higher risk of developing acute myeloid leukemia. This is why it is essential to adapt treatment at the right time.
Each case is different. Treatments for myelodysplastic syndromes vary according to their type and severity (low or high risk). The treatment offered will also depend on the age and condition of the patient. The objective of these treatments is to ease the symptoms, slow or stop the transformation of MSD to AML, and improve patient quality of life.
Bone marrow transplants are currently the only known cure for high-risk MDS. This option is rarely the first option for elderly patients, as it is considered very risky(5).
(1) MDS Foundation (mds-foundation.org)
(2) Béjar R, Steensma DP. Recent developments in myelodysplastic syndromes. 2014.
(3) Dotson JL, Lebowicz Y. Myelodysplastic syndrome StatPearls [Internet]. Updated July 18, 2022. Key statistics on myelodysplastic syndromes. American Cancer Society./Aster JC, Stone RM. Clinical manifestations, diagnosis and classification of myelodysplastic syndromes (MDS)./Neukirchen J, Schoonen WM, Strupp C et al. Incidence and prevalence of myelodysplastic syndromes: Data from the MDS registry Düsseldorf. Loèche Rés. 2011.
(4) Tests for Acute Myeloid Leukemia (AML) | American Cancer Society
(5) GUIDE DU PARCOURS DE SOINS Insuffisances médullaires et autres cytopénies chroniques – Syndromes myélodysplasiques HAS 2015
(6) Clinical impact of transformation to acute myeloid leukemia in patients with higher-risk myelodysplastic syndromes | Future Oncology (futuremedicine.com)
(7) Bulletin du Cancer Volume 109, Issue 2, February 2022, Pages 151-169 Clinical use and evolution of circulating biomarkers in the era of personalized oncology: From protein markers to bioclinical scores