Leucemia infantil e seu tratamento

Leucemia na infância

Leucemia é o câncer mais comum em crianças e adolescentes, representando quase 1 em cada 3 cânceres. A maioria das leucemias infantis são leucemia linfocítica aguda (ALL) e leucemia mieloide aguda (AML). As leucemias crônicas são raras em crianças.

Leucemia mielóide aguda pediátrica

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 sarcoma. Granulocytic sarcoma, or chloroma, is another name for myeloid sarcoma.

Tratamento da leucemia mieloide aguda

A quimioterapia para a maioria das crianças com leucemia mieloide aguda (LMA) é separada em duas fases:

• Indução
• Consolidação (intensificação)

As crianças com LMA devem ser tratadas em centros oncológicos ou hospitais com experiência nesta doença devido à intensidade do tratamento e ao potencial de consequências graves.

Quimioterapia de indução em pacientes com LMA

Daunorrubicina (daunomicina) e citarabina (ara-C), ambas administradas por vários dias seguidos, são os medicamentos quimioterápicos mais comumente utilizados para tratar a LMA. Dependendo de quão intenso os médicos desejam que o tratamento seja, o regime de tratamento pode ser repetido em 10 dias ou 2 semanas. Intervalos de tratamento mais curtos podem ser mais eficientes na erradicação das células leucêmicas, mas também podem resultar em efeitos adversos mais 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.

Consolidação

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.

Leucemia linfoblástica aguda da infância (LLA)

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.

Tratamento da leucemia linfoblástica aguda na infância

Crianças com leucemia linfoblástica aguda podem receber uma variedade de tratamentos (LLA). Alguns tratamentos são convencionais (já em uso), enquanto outros estão em testes clínicos. Um ensaio clínico de tratamento é um estudo de pesquisa que visa ajudar pacientes com câncer a melhorar seus tratamentos existentes ou aprender mais sobre tratamentos potenciais. Quando estudos clínicos comprovam que um novo tratamento é superior ao padrão atual, o novo tratamento poderá ser adotado como padrão.

Quatro tipos diferentes de opções de tratamento estão disponíveis

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.

Radioterapia em TODOS

A radioterapia é um tratamento de câncer que envolve o uso de alta energia raios X 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 TODAS que progrediu para o cérebro, medula espinhal ou testículos pode ser tratado com radioterapia externa. Também é possível usá-lo para preparar a medula óssea para um transplante de células-tronco.

Quimioterapia com transplante de células-tronco

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.

terapia-alvo

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.

Terapia de células T CAR

O sistema imunológico é usado para combater o câncer em Terapia de células T CAR, uma forma nova e inovadora de tratar a leucemia linfoblástica aguda (LLA). Neste tratamento, as células T são retiradas do sangue do paciente e geneticamente alteradas para produzir receptores de antígenos quiméricos (CARs). Esses CARs ajudam as células T a encontrar e atacar as células cancerígenas que possuem certos marcadores de superfície. Quando colocadas de volta no corpo do paciente, essas células T modificadas crescem e atacam as células cancerígenas com muita precisão, o que muitas vezes resulta em remissão. Tratamento com células T CAR tem muito potencial, mas pode apresentar problemas como síndrome de liberação de citocinas e neurotoxicidade. Isso mostra como é importante continuar pesquisando e aprimorando.

Você pode ler: Terapia de células T CAR na China

Os casos de leucemia pediátrica podem ser transferidos para outros irmãos?

Alguns jovens têm um irmão que seria um doador adequado de células-tronco. Uma vez que a leucemia esteja em remissão, um transplante de células-tronco pode ser recomendado para essas crianças, especialmente se a LMA apresentar alguns marcadores prognósticos desfavoráveis. A maioria dos estudos demonstrou que, embora isto melhore a sobrevivência a longo prazo em relação apenas à quimioterapia, também aumenta o risco de consequências significativas. Alguns médicos podem propor apenas a administração de quimioterapia agressiva a jovens com bons critérios de prognóstico e guardar o transplante de células estaminais até que haja uma recaída da LMA.

Você pode ler: Custo da terapia com células T CAR na China

Porque escolher-nos?

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.