Myelodysplastic syndromes (MDS), also known as myelodysplasia, are a group of bloodthe red bodily fluid that transports oxygen and other nutrients around the body disorders that result in immature red blood cellsthe basic structural and functional unit of all living things that do not mature into healthy red blood cells. Bone marrowsoft, spongy tissue found in bones that makes blood cells is the spongey, soft tissuetissue/the material that joins, holds up or surrounds inside body parts such as fat, muscle, ligaments and lining around joints found in the centre of most bones, and is primarily responsible for the production of blood cells in the body.
Blood is the bodily fluid of the circulatory system that provides nutrients and oxygen to our tissues, and helps remove waste from our bodies. There are three primary types of blood cells produced in bone marrow stem cells (immature blood cells). Red blood cells (RBCs), or erythrocytes, are responsible for providing oxygen to the tissues in our body, as well as transporting carbon dioxide to the lungs to be exhaled. White blood cells (WBCs) are responsible for fighting infectiona condition where harmful pathogens, such as bacteria, viruses or parasites, have entered the body and disease in the body. Plateletssmall disc-shaped blood cells that clump together to form clots to stop bleeding are blood cells that play a major role in blood clotting (or coagulation), which is an important process that helps reduce blood loss after an injury. MDS causes bone marrow to produce red blood cells that don’t develop into healthy cells, which makes the body more susceptible to infection.
MDSs are generally more common in men, and are often diagnosed after 60 years of age. However, anyone can develop this disease.
Types of Myelodysplastic Syndromes
There are several types of MDSs, some of which may progress into other types of MDS or acutenew, recent, comes with an urgent or significant sense, is sudden, sharp myeloid leukaemiacancer of blood and/or blood forming tissues if left untreated.
MDS with Single Lineage Dysplasia
MDS with single lineage dysplasiathe presence of abnormal cells in a tissue or organ (MDS-SLD), also known as refractory cytopenialow levels of red blood cells, white blood cells or platelets in the blood; one or more blood cell type can be affected with unilineage dysplasia, are rare disorders characterised by significantly low levels of one type of blood cell (RBCs, WBCs, or platelets). MDS-SLD can have a good prognosisto predict how a disease/condition may progress and what the outcome might be.
There are three subtypes of MDS-SLD.
Refractory Anaemia
Refractory anaemiaa condition where there aren't enough red blood cells in the blood, causing fatigue, weakness and pale skin and affecting how the body responds to infection is the subtype of MDS-SLD that is characterised by significantly low levels of red blood cells. This subtype can result in reduced oxygen flow throughout the body. Refractory anaemia is less aggressive than other forms of MDSs, and is classified as low riskthe possibility that something bad will happen.
Refractory Neutropenia
Refractory neutropeniaa condition where there are low levels of neutrophils (a type of white blood cell) in the body is the subtype of MDS-SLD that is characterised by significantly low levels of white blood cells. This subtype may show minimal symptoms, except an increased susceptibility to infection. Refractory neutropenia is generally classified as low risk.
Refractory Thrombocytopenia
Refractory thrombocytopenialow levels of platelets in the blood is the subtype of MDS-SLD that is characterised by significantly low levels of platelets.
MDS with Multilineage Dysplasia
MDS with multilineage dysplasia (MDS-MLD), also known as refractory cytopenia with multilineage dysplasia, are rare disorders characterised by significantly low levels of two or more types of blood cells (RBCs, WBCs, and platelets). They can occur in any combination of refractory anaemia, refractory neutropenia, and refractory thrombocytopenia, and is the most common type of MDS. MDS-MLD may not have as good of a prognosis as other types of MDS.
MDS with Ring Sideroblasts
MDS with ring sideroblasts (MDS-RS), also known as refractory anaemia with ring sideroblasts, is rare, and involves significantly low levels of red blood cells that have a ring of iron around the outer edge of the cell. This is caused by red blood cells being unable to process the iron used in the production of haemoglobin, causing it to build up in the cell. MDS-RS is further categorised into single lineage and multilineage dysplasia’s, with multilineage MDS-RS being more common.
MDS with Isolated Del(5q)
MDS with isolated del(5q) is a rare subtype of MDS that is characterised by a genetic mutation affecting chromosome five in patient DNA, or more specifically, a deletion of chromosome five. In most cases, this disease involves refractory anaemia, however it can also involve refractory neutropenia and refractory thrombocytopenia. MDS with isolated del(5q) is often non-aggressive, and can have a good prognosis.
MDS with Excess Blasts
MDS with excess blasts (MDS-EB) is a rare subtype of MDS categorised by the presence of excess blast cells, which are immature cells. They are characterised by significantly low levels of one or more types of blood cell (RBCs, WBCs, or platelets), occurring as refractory anaemia, refractory neutropenia, and refractory thrombocytopenia. MDS-EB may not have as good of a prognosis as other types of MDS.
There are two types of MDS-EB, based on the percentage of excess blasts present in the bone marrow and/or blood. Type one MDS-EB (MDS-EB1) is generally less severe, and occurs when blasts make up 5-9% in bone marrow, and less than 5% in the blood. Type two MDS-EB (MDS-EB2) is generally more severe, and occurs when blasts make up 10-19%, and between 5-19% in the blood.
MDS Unclassifiable
MDS unclassifiable (MDS-U) is a rare subtype that does not fit into any other category of MDS. The number of blasts in the bone marrow and the blood are often normal, and may be caused by genetic mutations.
Myelodysplastic/Myeloproliferative Neoplasms (MDS/MPN)
Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are a group of blood cancers that have characteristics of both MDS and MPN. Symptoms and treatments will vary based on the patient’s cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs characteristics.
Treatment
If cancer is detected, it is generally staged and graded based on size, metastasiswhen the cancer has spread to other parts of the body, also known as mets (whether the cancer has spread to other parts of the body) and how the cancer cells look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas and grading helps your doctors determine the best treatment for you.
MDS is not staged and graded like most cancers, as the outlook for these cancers are not based on tumoura tissue mass that forms from groups of unhealthy cells size or metastasis. Instead, scoring systems have been created to assess the outlook of these cancers based on other factors.
Revised International Prognostic Scoring System (IPSS-R)
The revised international prognostic scoring system (IPSS-R) is based on five factors:
- The percentage of blasts in bone marrow.
- The type and number of chromosome abnormalities in the cells.
- The level of RBCs (measured as haemoglobin) in the patient’s blood.
- The level of neutrophilsa type of white blood cell that act as a first responder to infections in the body (a type of WBC) in the patient’s blood.
Factors are given a score from 0 (very good) to 4 (very poor), and added up to be placed in a risk group:
- Very low risk.
- Low risk.
- Intermediate risk.
- High risk.
- Very high risk.
The score given helps to assess a person’s prognosis, as well as potential treatment options.
WHO Prognostic Scoring System (WPSS)
The world health organisation (WHO) prognostic scoring system (WPSS) is based on three factors:
- The type of MDS based on the WHO classification.
- Chromosome abnormalities (grouped as good, intermediate, or poor).
- Whether or not the patient needs regular blood transfusions.
Factors are given a score from 0 (very good) to 4 (very poor), and added up to be placed in a risk group:
- Very low risk.
- Low risk.
- Intermediate risk.
- High risk.
- Very high risk.
The score given helps to assess a person’s prognosis, as well as potential treatment options.
Treatment Options
Once your tumour has been staged and graded, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you. Treatment is dependent on several factors, including location, stage of disease and overall health.
Treatment options for MDS may include:
- Watch and waitthe close monitoring of a cancer without giving treatment until symptoms appear or worsen.
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.
- Stem cell transplanta procedure that involves replacing unhealthy blood-forming cells (stem cells) with healthy stem cells.
- Transfusion therapya procedure where blood or blood components are transferred into your bloodstream.
- Bone marrow transplanta procedure that involves replacing unhealthy bone marrow with healthy bone marrow.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
While the cause of MDS remain unknown, the following factors may increase the likelihood of developing the disease:
- Age.
- Genetic mutations.
- Exposure to certain chemicals, potentially including:
- Environmental chemicals.
- Benzene.
- Petroleum products.
- People who have had previous chemotherapy treatment.
- People who have had radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- People with certain congenital disorders, potentially including:
- Bloom’s syndrome.
- Down syndrome.
- Fanconi anaemia.
- Neurofibromatosis.
- Having a family history of MDS.
- Having a history of smoking.
Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.
Symptoms
Some patients with a MDS will appear asymptomatic in the early stages of disease. As symptoms progress, some of the following symptoms may appear.
- Anaemia, with symptoms potentially including:
- Fatiguea state of extreme tiredness or exhaustion, can be physical or mental.
- Dizziness.
- Weakness.
- Dyspneadifficulty breathing, shortness of breath.
- Paleness.
- Neutropenia, with symptoms potentially including:
- Recurrent infections.
- Fevers.
- Mouth ulcers.
- Thrombocytopenia, with symptoms potentially including:
- Easy bruising.
- Purpuraa rash of small, red dots due to small superficial capillary bleeds; generally larger than petichiae or petechiaea rash of small, red dots due to small superficial capillary bleeds; generally smaller than purpura.
- Bleeding of the nose and/or the gums.
- Weight loss/loss of appetite.
- Fever.
- Bone pain.
Not everyone with the symptoms above will have cancer but see your general practitioner (GP) if you are concerned.
Diagnosis
If your doctor suspects you have a MDS, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Blood teststesting done to measure the levels of certain substances in the blood.
- Bone marrow aspirationa procedure that involves inserting a needle into the hipbone (or the breastbone in some cases) to remove samples of solid and liquid bone marrow..
- Biopsyremoval of a section of tissue to analyse for cancer cells.
