Skip to content

Childhood acute myeloid leukaemia

Leukaemia is the most common cancer among children. It affects more than 350 children a year in our country, a third of which are under 4 years of age.  Leukaemia accounts for 30% of all paediatric cancers, with B-acute lymphoblastic leukaemia being the most common form among children (80% of cases). Acute myeloid leukaemia affects approximately 20% of paediatric leukaemia patients, especially below the age of 2 years.

The information provided on www.fcarreras.org is intended to support, not replace, the relationship that exists between patients/visitors to this website and their physician.

Alex

Acute myeloid leukaemia.

When I was only 2 and a half years old, I was diagnosed with acute myeloid leukemia. We contacted the Josep Carreras Leukemia Foundation, which helped us to better understand what was going on and filled us with hope. Fortunately, we also had a great team of doctors and nurses who did not give up, they took great care of me. After 3 cycles of chemotherapy, each one of them harder, we needed a bone marrow transplant, in our case from an umbilical cord blood unit. We were very fortunate to have a 100% compatible donor. Thanks to that other mom and another little brother, I am a happy, cheerful, full of vitality, energy, and healthy child. Besides, I want to celebrate with you that I came first in Catalonia in a math Olympics, I love numbers!”.

Information provided by Dr. Albert Català. Specialist in Haematology at the Sant Joan de Déu Hospital in Barcelona. Barcelona Medical Association (Co. 35799).

Acute leukaemias are a group of neoplastic diseases characterised by a malignant transformation and uncontrolled production of immature haematopoietic cells of the lymphoid (acute lymphoblastic leukaemia, ALL) or myeloid (acute myeloblastic leukaemia, AML) lineage.

In acute myeloid leukaemia, immature cells of the myeloid lineage (myeloblasts) proliferate abnormally, progressively invading the bone marrow and interfering with the production of normal blood cells, leading to bone marrow failure and infiltrating extramedullary tissues.

AML accounts for 20% of leukaemias diagnosed at this stage of life. The annual incidence of AML in the paediatric age group is 8 cases per million children under 15 years of age (US Cancer Institute’s Surveillance, Epidemiology and End Results (SEER) program). 

AML in infancy is most common before the age of two years.

Its incidence at during school years decreases and increases progressively with age from adolescence onwards.

As we have seen in ‘Leukaemia, bone marrow and blood cells’ , the bone marrow produces blood stem cells (immature cells) that will eventually develop into mature blood cells. A blood stem cell becomes a myeloid stem cell or a lymphoid stem cell.

A myeloid stem cell develops into one of the three types of mature blood cells:

  • Red blood cells, which carry oxygen to other tissues and organs in the body.
  • Granulocytes, white blood cells that help fight infection and other diseases.
  • Platelets, which help blood to clot when a blood vessel ruptures.

A lymphoid stem cell develops into a lymphoblast and later into one of the three types of lymphocytes (white blood cells):

  • B lymphocytes, which produce antibodies to help fight infections in the body.
  • T lymphocytes, which help B lymphocytes produce antibodies to fight infection.
  • Natural cytotoxic lymphocytes or NK lymphocytes (natural killer), a type of immune cell that contains enzymes which can destroy tumour cells or virus-infected cells.

In children affected by acute myeloid leukaemia, there are too many stem cells that transform into myeloblasts.

The specific causes of most cases of childhood acute myeloid leukaemia are not known. Only in a very small percentage of cases (about 5%) do acute leukaemias in the paediatric age group develop in patients with an underlying genetic disease with a predisposition to leukaemia such as Down syndrome or congenital bone marrow failure syndromes (e.g. Fanconi anaemia or dyskeratosis congenita, among others).

Leukaemia, like other cancers, is not contagious. See section Leukaemia, bone marrow and blood cells.

The two most commonly used schemes to classify AMLs are: the FAB classification (French-American-British), based on microscopic characteristics and the expression of certain proteins in the leukaemic cell (immunophenotype); and the new WHO (World Health Organisation) system, which incorporates genetic or molecular information of the leukaemic cell and clinical information of prognostic interest.

In Spain, in routine clinical practice, the most widespread classification is the FAB classification.

 

FABNombre% in paediatrics
M0AML with little differentiation2-5
M1AML without maturation10-15
M2AML with maturation25-30
M3Acute promyelocytic leukaemia5-10
M4Acute myelomonocytic leukaemia15-25
M4EoM4 + bone marrow eosinophilia10
M5Monoblastic/monocytic leukaemia15-25
M6Erythroid leukaemia1-3
M7Acute megakaryoblastic leukaemia5-10

The WHO classification, updated in 2022, assesses genetic and molecular aspects of leukaemic cells. The most common cytogenetic alterations in AML are translocations; displacement of a fragment from one chromosome to another chromosome (indicated as t). Example: t(8;21), a fragment of chromosome 8 moves to an area of chromosome 21; or within the same chromosome, t(16;16). Cytogenetic inversions can also be observed, which is when a chromosome segment changes direction within the chromosome itself (indicated as inv).

Translocations or inversions detected in cytogenetic studies result in rearrangements of genes located in the affected chromosomal regions. These are represented by the names of the genes involved, so in the case of t(8;21) it will generate a rearrangement of the RUNX1 and RUNX1T1 genes. Cytogenetic alterations have proven to be a very important prognostic factor and are used in most treatment protocols to determine their intensity.

In recent years, mutations in one or more genes have been described in the leukaemic cells of most patients. Some of them have been shown to have prognostic significance and to be relevant in defining the intensity of treatment. Thus, the recent WHO classification incorporates mutations in NPM1 and CEBPA, which are associated with a more favourable prognosis.

 

WHO classification of AML and related neoplasms
AML with recurrent genetic alterations
AML with t(8;21); RUNX1-RUNX1T1
AML with inv(16) or t(16;16); CBF-MYH11
AML with t(15;17); PML-RARA
AML with t(9;11); MLLT3-KMT2A
AML with t(6;9); DEK-NUP214
AML with inv(3) or t(3;3); GATA2, MECOM
AML (megakaryoblastic) with t(1;22); RBM15-MKL1
AML with NPM1 mutation
AML with biallelic mutation in CEBPA
Provisional entities:
AML with BCR-ABL1
AML with RUNX1 mutation
AML with changes in relation to myelodysplasia
AML in relation to treatment
Non-specific AML (NOS)
AML with little differentiation
AML without maturation
AML with maturation
Acute myelomonocytic leukaemia
Monoblastic/monocytic leukaemia
Erythroid leukaemia
Acute megakaryoblastic leukaemia
Acute basophilic leukaemia
Panmyelosis with acute myelofibrosis
Myeloid sarcoma
Myeloid proliferation in relation to Down Syndrome
Transient anomalous myelopoiesis
Myeloid leukaemia associated with Down Syndrome
Acute leukaemias of ambiguous lineage

Most paediatric cases fall into the group of AML with recurrent genetic alterations or non-specific AML.

The clinical presentation of acute myeloid leukaemia is variable and, in general, symptoms at diagnosis are due to leukaemic cells having infiltrated the bone marrow and other organs. Although it can present insidiously, childhood AML usually presents acutely, with a history of less than three months from clinical onset to diagnosis.

In acute myeloid leukaemia, the production of normal blood cells is disrupted by the growth of leukaemic cells in the bone marrow. This can lead to:

  • Tiredness, weakness, dizziness and paleness (due to anaemia).
  • Appearance of purple and small pink patches on the skin (petechiae) or other bleeding (due to low platelet counts): nosebleeds, bleeding from the gums or any other site.
  • Fever and infections that do not progress well (due to leukocyte malfunction).

Occasionally, patients may experience an enlargement of the lymph nodes, liver or spleen. Specific symptoms of infiltration of the central nervous system (headache, vomiting, drowsiness, etc.), skin (disseminated nodules or areas of thickened skin), mucous membranes (inflammation of the gums), eyes (blurred vision, blindness), among others, may also be observed.

At the onset of the disease, all these symptoms can be very similar to those of a virus infection. When symptoms continue for more than 2-4 weeks, a diagnosis can be obtained in most cases. As these symptoms are not specific or exclusive to leukaemia, it is very common for the patient to have visited a doctor several times before being diagnosed. Generally, this does not influence the child’s curative options.

In addition to basic blood and bone marrow studies (morphology, blood count, immunophenotyping) to be performed for all types of leukaemia, cytogenetic studies (to detect specific chromosomal abnormalities) and molecular studies (to detect specific genetic alterations) are essential for typing and classifying the disease. Certain cytogenetic and molecular alterations correlate with treatment sensitivity and relapse prognosis.

Also whether the disease has spread to the central nervous system should also be investigated by performing a lumbar puncture in order to analyse the fluid that surrounds the central nervous system (cerebrospinal fluid).

The goal of treatment for acute myeloid leukaemia is to eliminate the leukaemic cells to allow the bone marrow to return to its normal functioning.

The prognosis of AML in paediatric patients has improved significantly in recent decades. This improvement is due, among other things, to a better classification or stratification of each patient into risk groups, i.e. according to the individual risk of relapse. This stratification makes it possible to apply adapted therapeutic strategies, and therefore treatment will be intensified for patients with High Risk prognostic factors and reduced for those at Low Risk of relapse.

The ultimate goal of treatment is to achieve complete, deep (at molecular level) and permanent remission of the disease.

We basically differentiate between two phases of treatment: induction and post-remission or consolidation. The low-dose chemotherapy maintenance phase used in acute lymphoblastic leukaemia protocols has been abandoned in most AML protocols as it does not provide additional efficacy, except in the acute promyelocytic leukaemia subgroup (see below).  

The treatment of paediatric acute myeloid leukaemia is always based on intensive chemotherapy and the intravenous administration of different cytostatic drugs (chemotherapy) over several treatment cycles. Typically, although it may vary according to the protocol, 1 or 2 induction cycles are followed by 2-3 consolidation cycles.

Induction therapy aims to eliminate the leukaemic cells from the blood and most of the disease present in the bone marrow and thus restore its normal functioning, which is referred to as achieving complete remission. This clinical situation is usually achieved after the first induction cycle, although it may sometimes be necessary to administer two induction cycles to achieve a state of complete remission. With current protocols, more than 85% of patients will achieve complete remission after the induction phase.

When chemotherapy is administered intravenously, to avoid repeatedly puncturing a vein, specialists implant a special device called a catheter (content in spanish). The catheter is inserted into a large vein, which allows for the administration of all types of medication, as well as for drawing blood for blood tests, thus avoiding the child from enduring repeated needle punctures.

There is a type of catheter, called a port-a-cath (content in spanish), which is attached to a round plastic or metal reservoir under the skin of the chest. The port-a-cath is very practical for children because it is under the skin and does not allow the child to pull it out, it is less likely to become infected than other types of catheters and it allows the child to bathe.

This is followed by a post-remission or consolidation treatment that aims to eliminate residual leukaemic cells (minimal residual disease), potentially responsible for disease relapse.

If the chemotherapy is administered through a venous catheter, it reaches almost all the cells of the body via the blood. However, most chemotherapy drugs do not fully reach the cerebrospinal fluid that bathes the brain and spinal cord. This means that there are leukaemic cells that can survive in this fluid. In order to prevent leukaemic cells that reach the cerebrospinal fluid from surviving and causing a future relapse that will affect the nervous system, chemotherapy must be administered directly into the cerebrospinal fluid, via lumbar punctures (intrathecal chemotherapy). The use of cranial radiotherapy has been abandoned in most protocols.

In some patients, a transplant of haematopoietic stem cells (HSCT) (commonly known as a bone marrow transplantation) may be indicated as part of consolidation treatment. Most current protocols have abandoned autologous (from oneself) bone marrow transplantation for this pathology and, if indicated, HSCT from a compatible donor (allogeneic HSCT), either related or unrelated, is recommended.

HSCT in paediatric AML is a topic under constant review; the indications for HSCT in patients with AML in first complete remission (patients who have not relapsed) are controversial and are not the same in all countries. In general, this treatment is reserved for those cases considered high risk due to the biological characteristics of the disease or due to an inadequate response to chemotherapy treatment. Most patients who have relapsed and achieve a second state of complete remission are candidates for HSCT.

Alicia

Acute myeloid leukaemia.

“I’m Alicia, it all started when I was 11 years old, it was June, and I was very excited about the end of the school year party I had at that time. But I never would have imagined how that day would end…. My life took a 180-degree turn and I ended up in the hospital. The diagnosis was clear: acute myeloid leukaemia . From that day on, the hospital became my second home, I felt like I was in a hotel room! Without expecting it, the best gift of my life arrived. I was told that there was a donor 100% compatible with me and that this was my chance to be cured. And the transplant worked! Today I am recovered and happy. I am studying the career of my dreams, enjoying life and above all my loved ones to the fullest. I must say that this process was not easy at all, but now everything has been worth it. I never tire of thanking my family and friends, who have always been with me and have brought out the best smiles. Don’t let yourselves get down, you are not alone, and you must keep going because your effort, it will be worth it!”

The chances of cure are determined by the characteristics of the patient, the disease (genetic/molecular alterations), the treatment given and the response to this treatment. Unlike in adults, where patient characteristics such as advanced age or co-existence of other pathologies are usually very relevant, these are not relevant factors in the paediatric age group.

Survival of children with acute myeloid leukaemia has improved significantly in recent years, with survival rates of around 65%. This improvement has been possible thanks to an increase in the intensity of chemotherapy treatment, an improved classification of patients into risk groups, the implementation of more effective support measures (better antibiotics, ease of blood and platelet transfusions, nutritional support, specialised nursing…), as well as a considerable improvement in the selection of donors for HSCT.

In recent years, progress has been made towards more personalised treatments that take into consideration the characteristics of each individual and of the disease (genetic and molecular subtype, etc.). Research in this field is very active, and it is therefore not surprising that new drugs have been developed for these diseases. Most of them are not yet part of standard treatment protocols, but many are in advanced stages of clinical implementation.

Within the different lines of development of new drugs, the following should be highlighted:

  • New chemotherapy drugs: They act in a similar way to existing drugs, but have greater efficacy and/or lower toxicity. For example, liposomal daunorubicin allows for high doses of treatment to be administered, which are therefore highly effective, but with low toxicity to the heart, one of the main drawbacks of this group of drugs.
  • Targeted therapies: These are drugs that target specific components of tumour cells and have less impact on healthy cells. Within this group we highlight:
    • Monoclonal antibodies, which combine an antineoplastic drug with an antibody that recognises proteins from the tumour cell. The identification of cytogenetic-molecular alterations in most AML patients has enabled the development of new drugs that, by different mechanisms, act on these specific “molecular” targets and are therefore highly selective on neoplastic cells.
    • Immunotherapy harnesses the properties of the body’s own immune system to target leukaemia cells. It is one of the most researched areas in recent years, but still with scarce application in AML.
  • Acute Promyelocytic Leukaemia

One of the leukaemias that has benefited most from an individualised therapeutic strategy is acute promyelocytic leukaemia. In recent decades, thanks to scientific research, a substantial improvement in treatment has been achieved, from being a subtype of AML with a very poor prognosis to a disease that responds very well to treatment. This type of leukaemia is characterised by a translocation between chromosomes 15 and 17 [t(15:17)], which affects the retinoic acid receptor alpha (RARα or RARA) and confers a high sensitivity to treatment with holotransretinoic acid (ATRA).

  • Patients with Down syndrome

Children with Down syndrome have a 15 times higher risk of developing acute leukaemia. In the case of AML, the age of presentation is usually below the age of 5 years and typically the subtype is acute megakaryoblastic leukaemia (M7, according to FAB classification) or acute erythroid leukaemia (M6, according to FAB classification).

This group of patients has a high sensitivity to chemotherapy treatments and this has led to high cure rates. One of the main difficulties in achieving a cure is due to the high toxicity of some chemotherapy drugs and the high risk of infection. This is why different groups have been able to increase survival with adapted treatment protocols.

Up to 10% of children with Down syndrome have a transient proliferation of leukaemic cells during the first months of life. These cells are morphologically indistinguishable from an AML. This phenomenon is known as transient myeloproliferative syndrome or transient anomalous myelopoiesis. They usually have a benign course and often involute spontaneously during the first three months of life, although some patients may require treatment with low doses of cytostatics. Subsequent monitoring is important, as 20% of these children will develop AML during the first three years of life.

After completing the treatment, the child will have regular check-ups performed by their haematologist and by other specialists where necessary. Monitoring is carried out to assess possible relapse and to follow-up and treat possible long-term complications. These checks are progressively spaced out until they are carried out once a year. Long-term follow-up is recommended at least annually in order to early detection and treatment of any sequelae arising from treatment or leukaemia, should they appear.

Here are some general recommendations that answer some of the most frequently asked questions by parents of children with leukaemia:

  • Will their hair fall out? When? Should we cut it?

With the chemotherapy they will receive to treat the leukaemia, their hair will fall out. This usually happens 2-3 weeks after the start of chemotherapy. If the child has long hair, it is more appropriate to cut it short before it starts to fall out. It is neither necessary, nor psychologically desirable, to cut it during the first days of admission. Nor does this fact need to be explained to the child straight away. However, it is important to address this issue with the child before their hair starts to fall out. Hair regrows 2-4 weeks after starting the maintenance phase of treatment, where chemotherapy is less intense.

  • Hygiene

Since the child’s defences against infection are weakened (due to the illness itself and also due to the treatment administered), it is advisable to maintain adequate hygiene of the child’s body, the hospital room and the family home, including the child’s toys.

It is advisable to avoid dusty toys and cardboard boxes. Food should also not be stored outside the refrigerator. Plants are forbidden in the room, as there are fungal spores in the soil.

Tidiness facilitates cleaning by hospital cleaning staff.

  • Visits

It is advisable to reduce the number of visitors in the child’s room, as they may carry infections. It is recommended that there are no more than 2 companions in the room and that they wash their hands before entering. If any of the visitors has an infectious process (cold, conjunctivitis…) it is preferable that they do not visit.

In the case of a parent or other caregiver whose attention cannot be dispensed with, they should wear a mask and wash their hands before coming into contact with the child.

  • Food

A child receiving intensive chemotherapy treatment should be provided with a varied diet. When the white blood cell count is low, it is advisable to avoid raw foods that cannot be peeled (e.g. lettuce, strawberries, raw tomatoes).

Sometimes chemotherapy can reduce hunger, or even cause nausea. During the days of chemotherapy, it is not advisable to force your child to eat, as this can be counter-productive.

On the other hand, the corticosteroids (prednisone and dexamethasone) that the child will be administered during some phases of treatment can greatly increase their appetite, even causing anxiety. While they may be allowed to eat more than the meals served in the hospital, they should not be allowed to eat unlimited food, as they will often not tolerate it well and it can cause stomach pain.

CHILDHOOD LEUKAEMIA MATERIAL

The Josep Carreras Foundation has a story “The tough baby” aimed at children or siblings suffering from leukaemia. It is especially aimed at children up to the age of 6. If you want to order it, please send us an e-mail to imparables@fcarreras.es.

BONE MARROW TRANSPLANT

SUPPORT MANUALS

FOOD

OTHER

We also invite you to follow us through our main social media (Facebook, Twitter and Instagram) where we often share testimonies of overcoming this disease.

If you live in Spain, you can also contact us by sending an e-mail to imparables@fcarreras.es so that we can help you get in touch with other people who have overcome this disease.

* In accordance with Law 34/2002 on Information Society Services and Electronic Commerce (LSSICE), the Josep Carreras Leukemia Foundation informs that all medical information available on www.fcarreras.org has been reviewed and accredited by Dr. Enric Carreras Pons, Member No. 9438, Barcelona, ​​Doctor in Medicine and Surgery, Specialist in Internal Medicine, Specialist in Hematology and Hemotherapy and Senior Consultant of the Foundation; and by Dr. Rocío Parody Porras, Member No. 35205, Barcelona, ​​Doctor in Medicine and Surgery, Specialist in Hematology and Hemotherapy and attached to the Medical Directorate of the Registry of Bone Marrow Donors (REDMO) of the Foundation).

I want to receive the latest news