Leucémie infantile et son traitement

Leucémie chez l'enfant

Leucémie est le cancer le plus courant chez les enfants et les adolescents, représentant près de 1 cancer sur 3. La plupart des leucémies infantiles sont leucémie lymphoïde aiguë (LAL) ainsi que  leucémie myéloïde aiguë (LMA). Les leucémies chroniques sont rares chez les enfants.

Leucémie aiguë myéloïde pédiatrique

AML (acute myeloid leukaemia) is a blood and bone marrow malignancy that affects children. AML, also known as acute myelogenous leukaemia or acute nonlymphocytic leukaemia, is a kind of leukaemia that affects the blood cells. Acute cancers usually progress swiftly if they are not treated. Chronic cancers typically worsen over time. Myeloid stem cells in AML normally grow into myeloblasts, a type of immature white blood cell (or myeloid blasts). In AML, the aberrant myeloblasts, or leukaemia cells, do not mature into healthy white blood cells. Leukemia cells can accumulate in the blood and bone marrow, making it difficult for healthy white blood cells, red blood cells, and platelets to thrive. Infection, anaemia, and simple bleeding are all possible outcomes. Outside of the blood, leukaemia cells can travel to other regions of the body, such as the central nervous system (brain and spinal cord), skin, and gums. Leukemia cells can sometimes produce a solid tumour termed a myeloid sarcome. Granulocytic sarcoma, or chloroma, is another name for myeloid sarcoma.

Traitement de la leucémie aiguë myéloïde

La chimiothérapie pour la plupart des enfants atteints de leucémie myéloïde aiguë (LMA) est séparée en deux phases :

• Induction
• Consolidation (intensification)

Les enfants atteints de LAM doivent être traités dans des centres anticancéreux ou des hôpitaux qui ont l'expérience de cette maladie en raison de l'intensité du traitement et du potentiel de conséquences graves.

Chimiothérapie d'induction chez les patients atteints de LAM

La daunorubicine (daunomycine) et la cytarabine (ara-C), toutes deux administrées plusieurs jours de suite, sont les médicaments de chimiothérapie les plus couramment utilisés pour traiter la LAM. Selon l'intensité du traitement souhaité par les médecins, le schéma thérapeutique peut être répété dans 10 jours ou 2 semaines. Des intervalles de traitement plus courts peuvent être plus efficaces pour éradiquer les cellules leucémiques, mais ils peuvent également entraîner des effets indésirables plus graves. As part of their induction treatment, some children with AML may get a dose of the targeted medication gemtuzumab ozogamicin (Mylotarg) in addition to chemo. If the doctors believe the leukaemia will not react to just two chemo medications, they may add another chemo agent like etoposide or 6-thioguanine to the mix. This group includes children who have a high number of white blood cells or whose leukaemia cells have particular genetic defects. The chemo medicines are given again and again until the bone marrow reveals no more leukaemia cells. This usually happens after two or three therapy cycles. Most children with AML will also get intrathecal chemotherapy (chemotherapy delivered directly into the cerebrospinal fluid, or CSF) to help prevent leukaemia from relapsing in the brain or spinal cord. The use of brain radiation therapy is becoming less common. After induction therapy, between 85 percent to 90 percent of children with AML go into remission. This indicates that no symptoms of leukaemia have been identified using normal lab tests, but it does not necessarily imply that the leukaemia has been healed.

Consolidation

After the induction phase, the consolidation (intensification) phase begins. The goal is to use a more aggressive treatment to kill any remaining leukaemia cells. Some youngsters have a sibling who would be a suitable stem cell donor. Once the leukaemia is in remission, a stem cell transplant may be advised for these children, especially if the AML has some unfavourable prognostic markers. Most studies have shown that while this improves long-term survival over chemotherapy alone, it also increases the risk of significant consequences. Some clinicians may propose only delivering aggressive chemotherapy to youngsters with good prognostic criteria, and saving the stem cell transplant until if the AML relapses. Consolidation consists of heavy doses of the chemo medication cytarabine (ara-C) for most children who do not have a good stem cell donor. It’s also possible to use daunorubicin. It is normally given for a period of at least a few months. If the targeted medicine gemtuzumab ozogamicin (Mylotarg) was given during induction, it will almost certainly be given again during this stage of treatment. For as long as intensification continues, intrathecal chemo (into the CSF) is normally given every 1 to 2 months. Children with AML do not require maintenance chemotherapy (other than those with APL). Supportive care is a key element of AML treatment (proper nursing care, nutritional support, antibiotics, and blood transfusions). The aggressive therapy for AML frequently destroys much of the bone marrow, resulting in significant blood cell shortages, as well as other catastrophic consequences. The current high remission rates would not be conceivable without antibiotic treatment of infections or transfusion assistance.

Leucémie aiguë lymphoblastique (LAL) infantile

Acute lymphoblastic leukaemia in children (also known as ALL or acute lymphocytic leukaemia) is a blood and bone marrow malignancy. If left untreated, this type of cancer usually worsens swiftly. Too many stem cells turn into lymphoblasts, B lymphocytes, or T lymphocytes in a child with ALL. Leukemia cells are another name for these cells. These leukaemia cells do not function like normal lymphocytes and are unable to effectively fight infection. In addition, when the number of leukaemia cells in the blood and bone marrow rises, there is less room in the blood and bone marrow for healthy white blood cells, red blood cells, and platelets. Infection, anaemia, and simple bleeding are all possible outcomes.

Traitement de la leucémie aiguë lymphoblastique de l'enfant

Les enfants atteints de leucémie lymphoblastique aiguë peuvent recevoir divers traitements (LAL). Certains traitements sont courants (déjà utilisés), tandis que d’autres font l’objet d’essais cliniques. Un essai clinique de traitement est une étude de recherche qui vise à aider les patients atteints de cancer à améliorer leurs traitements existants ou à en apprendre davantage sur les traitements potentiels. Lorsque des études cliniques prouvent qu’un nouveau traitement est supérieur à la norme actuelle, le nouveau traitement peut être adopté comme norme.

Quatre différents types d'options de traitement sont disponibles

Chemotherapy is a cancer treatment that involves administering chemicals to cancer cells in order to limit their growth, either by killing them or preventing them from growing. Chemotherapy medications enter the bloodstream and can reach cancer cells all throughout the body when taken by mouth or injected into a vein or muscle (systemic chemotherapy). Chemotherapy that is administered directly into the cerebrospinal fluid (intrathecal), an organ, or a bodily cavity such as the abdomen targets cancer cells primarily in specific regions (regional chemotherapy). Combination chemotherapy is a type of cancer treatment that involves the use of multiple anticancer drugs. The method of chemotherapy administration is determined by the child’s risk group. Anticancer medications are given in higher doses to children with high-risk ALL than to those with standard-risk ALL. Childhood ALL that has spread or may spread to the brain and spinal cord is treated with intrathecal chemotherapy.

Radiothérapie dans la LAL

La radiothérapie est un traitement contre le cancer qui implique l'utilisation de haute énergie radiographies or other forms of radiation to kill or stop cancer cells from developing. External radiation therapy involves sending radiation from a machine outside the body to the cancerous spot. Childhood TOUTES qui a progressé vers le cerveau, la moelle épinière ou les testicules peut être traité par radiothérapie externe. Il est également possible de l’utiliser pour préparer la moelle osseuse en vue d’une greffe de cellules souches.

Chimiothérapie avec greffe de cellules souches

Chemotherapy is a treatment that is used to kill cancer cells. Total-body irradiation is used in conjunction with chemotherapy in children aged 3 and up. The cancer treatment also kills healthy cells, including blood-forming cells. A stem cell transplant is a procedure that replaces blood-forming cells in the body. Stem cells (immature blood cells) are extracted from a donor’s blood or bone marrow, frozen, and stored. The stored stem cells are thawed and delivered to the patient via an infusion after the patient has completed chemotherapy and radiation therapy. These stem cells develop into (and replenish) blood cells in the body. For children and adolescents with ALL, stem cell transplantation is rarely used as a first-line treatment. It’s being utilized increasingly frequently as part of relapse treatment for ALL.

thérapie ciblée

Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells. Targeted therapies usually cause less harm to normal cells than chemotherapy or radiation therapy do. There are different types of targeted therapy: Tyrosine kinase inhibitor (TKIs) therapy: This treatment blocks the enzyme, tyrosine kinase, that causes stem cells to develop into more white blood cells than the body needs. Imatinib mesylate and dasatinib are TKIs used in the treatment of children with Philadelphia chromosome–positive ALL. Ruxolitinib is a TKI that is being studied in the treatment of newly diagnosed high-risk ALL. Monoclonal antibodies: Monoclonal antibodies are immune system proteins made in the laboratory to treat many diseases, including cancer. As a cancer treatment, these antibodies can attach to a specific target on cancer cells or other cells that may help cancer cells grow. The antibodies are then able to kill the cancer cells, block their growth, or keep them from spreading. Monoclonal antibodies are given by infusion. They may be used alone or to carry drugs, toxins, or radioactive material directly to cancer cells. Blinatumomab and inotuzumab are monoclonal antibodies being studied in the treatment of refractory childhood ALL. Blinatumomab is also being studied in the treatment of standard-risk ALL.

Thérapie CAR T-Cell

Le système immunitaire est utilisé pour combattre le cancer Thérapie par les cellules CAR T, une nouvelle façon révolutionnaire de traiter la leucémie lymphoblastique aiguë (LAL). Dans ce traitement, les lymphocytes T sont prélevés dans le sang du patient et modifiés génétiquement pour produire des récepteurs antigéniques chimériques (CAR). Ces CAR aident les cellules T à trouver et à attaquer les cellules cancéreuses qui comportent certains marqueurs de surface. Lorsqu'elles sont réintroduites dans le corps du patient, ces cellules T modifiées se développent et attaquent les cellules cancéreuses de manière très précise, ce qui entraîne souvent une rémission. Traitement des cellules CAR T a beaucoup de potentiel, mais il peut poser des problèmes tels que le syndrome de libération des cytokines et la neurotoxicité. Cela montre à quel point il est important de continuer à le rechercher et à l’améliorer.

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Les cas de leucémie pédiatrique peuvent-ils être transférés à d'autres frères et sœurs ?

Certains jeunes ont un frère ou une sœur qui pourrait être un donneur de cellules souches approprié. Une fois la leucémie en rémission, une greffe de cellules souches peut être conseillée à ces enfants, surtout si la LAM présente des marqueurs de pronostic défavorables. La plupart des études ont montré que même si cela améliore la survie à long terme par rapport à la chimiothérapie seule, cela augmente également le risque de conséquences importantes. Certains cliniciens peuvent proposer de n'administrer une chimiothérapie agressive qu'aux jeunes présentant de bons critères de pronostic et de conserver la greffe de cellules souches jusqu'à une rechute de la LMA.

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Pourquoi choisir Becker Automobile?

Our ability to completely comprehend the biology of your child’s cancer is one of our greatest assets and sets us apart from most paediatric leukaemia programmes. We have the tools, experience, and resources to investigate the roots of your child’s illness down to the most fundamental molecules, thanks to a strong partnership between our paediatric leukaemia clinicians and researchers, the Department of Pathology, and the Pediatric Translational Medicine Program. Our staff evaluates your child’s cancer to check if there are any genetic alterations present. The results of these tests can assist us in determining the most effective treatment. We are convinced that our paediatric haematology department, which has more than 20 years of expertise treating young leukaemia cases, will handle this case and ensure that the patient is in complete remission as soon as possible. Our clinical genetics experts can help you and your family understand how genetics plays a role in your child’s leukaemia and whether any genetic alterations may affect other family members. We’ll be there for you every step of the way, from the initial consultation to the follow-up care. We provide the direction and assistance you and your family require.