Leukemia in Children

Did you know that leukemia is the most common cancer in children?

In fact, there are several types of leukemia that are named based on their development. Most children with leukemia will have acute lymphocytic leukemia (ALL), fewer children will have acute myeloid leukemia (AML), and the chronic versions of lymphocytic leukemia and myeloid leukemia are rare. A final type of leukemia that exists is juvenile myelomonocytic leukemia (JMML) which is neither acute nor chronic. These types of leukemia are similar, so the focus of this article will be ALL as it is the most common type of leukemia in children.

ALL is a cancer of the blood and bone marrow, progresses rapidly and creates immature blood cells which can’t fight diseases. It attacks cells that will eventually become lymphocytes (a type of white blood cell). Common symptoms of ALL include bleeding from the gums, bone pain, fever, frequent infections, frequent or severe nosebleeds, lumps caused by swollen lymph nodes in and around the neck, armpits, abdomen or groin, pale skin, shortness of breath, weakness, and fatigue.

Although the exact cause is not known, scientists think that ALL is caused by a mutation in the bone marrow cells’ DNA which leads to uncontrolled cell division and growth. This causes the blood cell production to get out of control. People with ALL will have bone marrow that produces lymphoblasts which do not function properly and disturb healthy cells.

Two types of ALL exist, and these are named based on the type of lymphocyte that is impacted. There are two types of lymphocytes - B-lymphocytes and T-lymphocytes - therefore the two types of ALL are B-ALL and T-ALL.

Oncologists diagnose ALL by studying the patient’s medical history and performing a physical examination and other tests such as a complete blood count, bone marrow aspirate, biopsy, lumbar puncture, and a chest x-ray.

Risk factors for developing ALL are previous cancer treatment (many cancer treatments utilize harmful chemicals like benzene which is a product used to make glue, cigarettes, cleaning supplies, detergents, and art supplies), exposure to radiation, certain viral infections (such as human T-cell lymphoma/leukemia virus-1 (HTLV-1) - HTLV-1 is more common in Japan and Carribean region than the US), and genetic disorders (such as down syndrome, klinefelter syndrome, fanconi anemia, bloom syndrome, ataxia-telangiectasia, neurofibromatosis, li-Fraumeni syndrome). There is no known way to prevent ALL.

ALL can be confused with another cancer known as lymphoma which is cancer of the lymph nodes. According to the American Cancer Society, “if at least 20% of the bone marrow is made up of cancerous lymphocytes, the disease is considered leukemia”.

On a brighter note, according to the Children’s Hospital of Philadelphia, ALL has the highest cure rates of all childhood cancers.

Treatment of ALL varies based on the symptoms the child has however common treatments include chemotherapy, intrathecal medications/chemotherapy, blood transfusions, antibiotics, placement of permanent line (a central venous line is used to take blood or give medication and a plastic tube/catheter is inserted into a large vein in the chest), radiation therapy, and blood and marrow transplantation. These treatment options are harsh on a child’s body and may have long term side effects. Furthermore, treatment can take months to years and occurs in stages based on the patient’s circumstances. The stages of ALL treatment are the following: induction - a combination of chemotherapeutic drugs to target leukemia cells (this is to get the patient in remission), consolidation - one to two months of drug treatment (rare leukemia cells are targeted), interim maintenance - patient receives methotrexate with other chemotherapy agents, intensification - repetition of chemotherapy but more intense, and maintenance - repeated courses of less intense chemotherapy every month for 2-3 years.

AML begins in immature myeloid cells - cells that become white blood cells (other than lymphocytes), red blood cells, or platelet-making cells. It is similar to ALL but targets different cells. There is no way to prevent AML, and it utilizes treatment similar to ALL. AML can starts in any of these immature bone marrow cells: myeloblasts (become WBCs known as granulocytes), monoblasts (become WBCs known as monocytes and macrophages), erythroblasts (become RBCs), and megakaryoblasts (become megakaryocytes - cells that make platelets). It is possible to experience a combination of ALL and AML.

Furthermore, AML has several subtypes which are based on “the type of bone marrow cell the leukemia cells come from, and how mature the cells are (the immunophenotype of the leukemia), if the leukemia cells have certain gene or chromosome changes, if the leukemia is related to the treatment of an earlier cancer (with chemotherapy or radiation, and if the child with leukemia has Down syndrome” (American Cancer Society). A special subtype of AML is acute promyelocytic leukemia (APL) because it is treated differently as it utilizes the induction, consolidation, and maintenance treatment from ALL treatments and has a better outlook.

As mentioned earlier, chronic leukemia is rare when compared to acute forms of leukemia. In chronic leukemia, cells mature but not completely and they are identical to normal cells. Similar to acute leukemia, chronic leukemia cells cannot fight disease and can build up and impair the body’s ability to fight disease - chronic leukemia is harder to treat. Chronic lymphocytic leukemia is more rare than chronic myeloid leukemia.

Complications of leukemia include serious infections, severe bleeding, and thickened blood from large numbers of leukemia cells. Long term complications of leukemia and its treatment include return of the leukemia, growth of other cancers, heart and lung problems, learning problems, slowed growth and development, problems with the ability to have children in the future, bone problems such as thinning of bones (osteoporosis).

According to Stanford Children’s Health, getting medical treatment immediately after the diagnosis is essential for the best prognosis, ongoing follow-up care during and after treatment is needed, and new treatments are being tested to improve outcomes and to lessen side effects.

Leukemia is a cancer that affects blood cells. The disease is overwhelming and weakens the child’s body. The treatment is intense and powerful but it drains the energy from a child’s body. The public can support children fighting cancer by participating in fundraising events that credible organizations set up, educate ourselves about cancer, offer moral and emotional support to those dealing with cancer, and show love to those who have fought or are fighting cancer.

Sources:

https://www.cancer.org/cancer/leukemia-in-children.html

https://www.mayoclinic.org/diseases-conditions/acute-lymphocytic-leukemia/symptoms-causes/syc-20369077

https://www.cancer.org/cancer/acute-lymphocytic-leukemia/causes-risks-prevention.html

https://www.cancer.org/cancer/acute-lymphocytic-leukemia/about/what-is-all.html

https://www.chop.edu/conditions-diseases/acute-lymphoblastic-leukemia-all

https://www.cancer.org/cancer/chronic-myeloid-leukemia/about/what-is-cml.html

https://www.stanfordchildrens.org/en/topic/default?id=leukemia-90-P02324