The myelodysplastic syndromes (MDS) are a group of bone marrow failure disorders. The bone marrow is the factory for the production of blood cells including red blood cells (energy), white blood cells (immune system), and platelets (clotting). In MDS, the bone marrow is damaged and fails to produce enough blood cells (cytopenias).
The cause of MDS is unknown in more than 80% of patients. MDS is more common in men and is more common in older individuals. Exposure to chemicals such as benzene and other solvents and tobacco are known to increase the risk of developing MDS. Patients who receive certain types of chemotherapy or radiation treatment for other cancers may also be at increased risk of developing MDS. Inherited cases, occurring in childhood, are rare.
MDS is a rare disease with only 10-15,000 new patients diagnosed each year. However, the incidence may be increasing as the population ages and more individuals are exposed to toxic chemicals and/or prior chemotherapy treatments.
The main symptoms of MDS are a consequence of the low blood counts (cytopenias):
a) Fatigue, shortness of breath, palpitations (common anemia symptoms from low red blood cells)
b) Fever, recurrent or prolonged infections (common neutropenia symptoms from low white blood cells)
c) Bruising, petechiae, or bleeding (common thrombocytopenia symptoms from low platelet counts)
Routine complete blood counts (CBC) often indicate decreased levels of blood cells and prompt referral to a blood specialist (hematologist or oncologist). After excluding vitamin deficiencies (such as low iron or vitamin B12), a bone marrow evaluation is performed. This involves inserting a needle into the hip bone and removing a small specimen for examination under the microscope. A diagnosis of MDS requires abnormal changes (dysplasia) observed in at least one blood cell factory. The sample may also be examined for changes (mutations) of chromosomes or genes, which determine prognosis and may influence treatment decisions.
The International Prognostic Scoring System (IPSS) is the most commonly utilized tool to estimate prognosis and guide treatment planning. This simple system uses the number of cytopenias, types of cytogenetic abnormalities and percentage of leukemia blasts to place patients into prognostic groupings. The scoring system has been recently revised and other systems are available. A scoring calculator is available on-line on the MDS Foundation website.
Treatment selection for MDS is highly individualized based on the subtype of MDS and the prognostic score (R-IPSS). In patients with lower risk disease attention towards improving quality of life issues becomes paramount. Transfusional support reduce fatigue and shortness of breath is common. Blood growth factors (such as erythropoietin) and low dose chemotherapy options may also be appropriate. For patients with higher risk disease treatments are often geared towards extending life. Outpatient chemotherapy options have been proven to be beneficial and are usually well tolerated even in older individuals. Bone marrow transplants may be considered as a curative treatment in healthier younger patients.
Some of the most common treatment options are:
New therapies requiring testing before they become part of the standard treatment options for patients with MDS. A clinical trial is a research study designed to learn if a new treatment is beneficial. Clinical trials may be offered both as part of the first treatment options or later in the treatment course. Enrollment in a clinical trial requires your informed consent and typically will require additional discussions with research personnel. Studies are monitored by local and federal rules to maximize patient safety. New medications often go through 3 steps towards approval: Phase I studies involve the newest medications with the goals of establishing dose and safety – they entail the most unknown risk. Phase II studies focus on establishing whether the medication works. Phase III studies are often the last step, comparing the new treatment with the current standard treatment to determine which is better. Until everyone is cured, clinical trials are important in advancing care.
Under the microscope the bone marrow appears abnormal (dysplasia) and may have changes at a genetic-molecular level. Therefore, MDS meets the formal definition of cancer. However, from a clinical standpoint, MDS acts more like a marrow failure disease. MDS may turn into leukemia which can be very aggressive.
Being open and asking questions is an important part of MDS care. Talk to the doctors, nurses and other health professionals. Inquire about social and financial support if needed. Chat with other patients and consider support groups. The more you tell your team, the better they can help you. The MDS Foundation is also available to guide you through the journey.