Childhood leukemia

Childhood leukemia is leukemia that occurs in a child and is a type of childhood cancer. Childhood leukemia is the most common childhood cancer, accounting for 29% of cancers in children aged 0–14 in 2018. There are multiple forms of leukemia that occur in children, the most common being acute lymphoblastic leukemia (ALL) followed by acute myeloid leukemia (AML). Survival rates vary depending on the type of leukemia, but may be as high as 90% in ALL.aggressive: Sézary disease Childhood leukemia is leukemia that occurs in a child and is a type of childhood cancer. Childhood leukemia is the most common childhood cancer, accounting for 29% of cancers in children aged 0–14 in 2018. There are multiple forms of leukemia that occur in children, the most common being acute lymphoblastic leukemia (ALL) followed by acute myeloid leukemia (AML). Survival rates vary depending on the type of leukemia, but may be as high as 90% in ALL. Leukemia is a hematological malignancy or a cancer of the blood. It develops in the bone marrow, the soft inner part of bones where new blood cells are made. When a child has leukemia, the bone marrow produces white blood cells that do not mature correctly. Normal healthy cells only reproduce when there is enough space for them. The body will regulate the production of cells by sending signals of when to stop production. When a child has leukemia, the cells do not respond to the signals telling them when to stop and when to produce cells. The bone marrow becomes crowded resulting in problems producing other blood cells. Common childhood leukemia signs and symptoms include excessive tiredness, easy bruising or bleeding, bone pain and paleness. Leukemia is usually described either as 'acute', which grows quickly, or 'chronic', which grows slowly. The vast majority of childhood leukemia is acute, and chronic leukemias are more common in adults than in children. Acute leukemias typically develop and worsen quickly (over periods of days to weeks). Chronic leukemias develop over a slower period of time (months), but are more difficult to treat than acute leukemias. The following are some of the main types of leukemia that occur in children. The most common form childhood leukemia is acute lymphocytic (or lymphoblastic) leukemia (ALL), which makes up 75-80% of childhood leukemia diagnoses. ALL is a form of leukemia that affects lymphocytes, a type of white blood cells which fights infection. When a patient has ALL, the bone marrow makes too many immature white blood cells and they do not mature correctly. These white blood cells also do not work correctly to fight infection. The white blood cells over-produce, crowding the other blood cells in the bone marrow. Another type of acute leukemia is acute myelogenous leukemia (AML). AML accounts for most of the remaining cases of leukemia in children, comprising about 20% of childhood leukemia. AML is cancer of the blood in which too many myeloblasts (immature white blood cells) are produced in the bone marrow. The marrow continues to produce abnormal cells that crowd the other blood cells and do not work properly to fight infection. Acute promyelocytic leukemia (APL) is a specific type of AML. In this leukemia promyelocytes are produced and build up in the bone marrow. A specific chromosome translocation (a type of genetic change) is found in patients with APL. Genes on chromosome 15 change places with genes on chromosome 17. This genetic change prevents the promyelocytes from maturing properly. Chronic myelogenous leukemia (CML) is a chronic leukemia that develops slowly, over months to years. CML is rare in children, but does occur. CML patients have too many immature white blood cells being produced, and the cells crowd the other healthy blood cells. A chromosome translocation occurs in patients with CML. Part of chromosome 9 breaks off and attaches itself to chromosome 22, facilitating exchange of genetic material between chromosomes 9 and 22. The rearrangement of the chromosomes changes the positions and functions of certain genes, which causes uncontrolled cell growth. Chronic lymphocytic leukemia (CLL) is another form of chronic leukemia, but is extremely rare in children.