Children's Hospital Colorado

Leukemia in Children

What is leukemia?

Leukemia is a cancer of the bone marrow, the substance inside of bones that makes blood cells. Because it primarily affects the blood, leukemia is typically called a blood cancer.

Leukemia affects lymphocytes, or white blood cells, a part of the immune system that helps fight infection. In leukemia, the bone marrow produces a lot of abnormal white blood cells that don’t function the way they should.

What causes leukemia in children?

Leukemia is the result of the rapid buildup of abnormal white blood cells. It’s not known exactly what causes leukemia in children, although it is most likely related to changes in the genes within blood cells, possibly as the result of a viral infection or other factors. These changes are not usually inherited from parents; in other words, having one child with leukemia does not typically mean siblings or other family members are at risk.

Who gets leukemia?

Leukemia can occur in children of any age, from infancy through adulthood; however, acute lymphoblastic leukemia (ALL) is most common among children 3 to 5 years old. Acute myeloid leukemia, or AML, is the second-most common type of childhood leukemia. The rate of AML tends to rise as children get older, occurring most often in teens and young adults.

Children with certain genetic disorders, like Down syndrome, may have a higher risk for developing leukemia.

What are the signs and symptoms of leukemia?

The buildup of abnormal blood cells in childhood leukemia can impact the body in a lot of different ways. Too many abnormal white blood cells can crowd out normal, healthy red blood cells and platelets, which prevents the healthy cells from doing their jobs.

For example, red blood cells carry oxygen to all parts of the body. A lack of red blood cells is called anemia, which can make people very tired and can make the heart work too hard. Platelets help the blood clot, which stops bleeding. A low number of platelets usually means people bruise more easily and severely.

The job of white blood cells is to fight infection by attacking infectious agents. The abnormal white blood cells of leukemia will sometimes attack healthy parts of the body.

Leukemia symptoms may include:

  • Bruising
  • Bleeding
  • Fatigue
  • Fever
  • Bone pain
  • Infections

Symptoms like these do not always indicate leukemia. If they last a couple of weeks or more, however, a doctor can perform tests to determine the cause.

What tests are used to diagnose leukemia?

The first step to diagnosing leukemia is to take a blood sample and get a test called a complete blood count, which tells doctors the number and type of blood cells in your child’s body.

In children with leukemia, the numbers of white blood cells, red blood cells and platelets are not normal. In some types of leukemia, all three cell types are abnormal; in others, only one type of blood cells is affected. Sometimes it’s possible for doctors to see cancerous blood cells, called blasts, under a microscope and diagnose leukemia that way.

In order to understand the type of leukemia and pick the best course of treatment for your child, pediatric cancer specialists must perform a bone marrow aspiration and biopsy, which means they take a sample of your child’s bone marrow, out of either the hip bone or a bone in the back. This test is usually done when the child is sedated, so that they won’t feel any pain. Results are usually available within a day or two of the procedure.

What are the types of childhood leukemia?

Every child is unique, so every case of childhood leukemia will have differences. By and large, though, nearly all cases of childhood leukemia are acute, meaning fast-growing (as opposed to chronic leukemias, which are slow-growing), and fall into one of two basic categories:

  • Acute lymphoblastic leukemia (ALL): White blood cells go through several different phases as they mature. Acute lymphoblastic leukemia starts early in the white blood cell life cycle, when they are called lymphocytes. Cancerous lymphocytes are called lymphoblasts. About 75% of childhood leukemia patients have some form of ALL, which is most often treatable and curable, usually with well-established medicines such as chemotherapy. The overall survival rate for ALL is very good, approaching 90%, although it varies somewhat depending on the type of leukemia and the risk factors involved.
  • Acute myeloid leukemia: Normally found in the bone marrow, healthy myeloid cells mature to become different types of white blood cells. In children with AML, cancerous myeloid cells, also called myeloblasts, reproduce too quickly and circulate in the blood. AML accounts for about 20% of all childhood leukemias. AML is also treated with chemotherapy, sometimes requiring a bone marrow transplant as well.

Some children do get a type of leukemia called chronic myelogenous leukemia as well, but it’s very rare, accounting only for about 1% of cases. Acute leukemias are most common in children, whereas chronic leukemias are more common in adults.

How is leukemia treated?

In general, most leukemia is treated primarily with chemotherapy (more rarely followed by radiation or a bone marrow transplant when necessary). The good news is that most children with leukemia are usually cured after chemotherapy, meaning they’re cancer-free five years out from treatment. By that point, it’s extremely rare for leukemia to come back.

How does chemotherapy work?

Chemotherapy can be given in many different ways, but its job is to kill cancer cells. Some chemotherapy is given as a pill or a liquid to swallow. Some is given in a vein, which is called intravenous, or IV. Other times, chemotherapy is injected into the skin or a muscle, similar to how vaccines can be given.

For about 80% of leukemia patients, chemotherapy alone will be enough. Here, our treatment regimens are carefully planned and optimized for each patient’s unique biology and treatment response by a dedicated team. These teams include a dedicated oncologist, pediatric nurse practitioner, physician assistant, nurse care-coordinator, oncology-specific physical and occupational therapists, child life specialists and dedicated pharmacists, all specializing specifically in leukemia care.

And as the largest center in Colorado for the treatment of pediatric leukemia, we have many additional programs and therapies available for newly diagnosed pediatric cancer patients, as well as for those whose leukemia may not have responded well to treatment or has returned after initially being treated.

Other therapies for leukemia treatment

Leukemia affects the bone marrow, so some childhood leukemia patients may benefit from bone marrow transplant when needed. Our large, nationally accredited Bone Marrow Transplant and Cellular Therapeutics Program is one of the most experienced programs of its kind in the country: We’ve performed more than 1,000 bone marrow and stem cell transplants in children over the past 25 years. Our specialty teams are world experts in bone marrow transplant and cellular therapeutics.

In addition, our Experimental Therapeutics Program is an international leader in novel treatments and interventions and is available to our leukemia patients who have not responded well to initial therapy or have relapsed.

For some patients whose leukemia has relapsed or who are not responding well to treatment, we also offer a new treatment known as CAR-T cell therapy, where the patient’s own immune cells are genetically modified to destroy cancer cells. This cutting-edge therapy is available at only a handful of pediatric cancer centers around the world.

Why choose Children’s Hospital Colorado for your child’s leukemia?

At Children’s Colorado’s Center for Cancer and Blood Disorders, our specialists are national and international leaders in the treatment of leukemias and other cancers and blood diseases. We’re the largest center in the region, and the most experienced: In fact, our highly specialized pediatric cancer experts are involved in developing treatment plans and regimens used around the world — which is why we’re able to offer leading-edge and proven oncology treatment protocols for leukemia with some of the best outcomes anywhere.

That’s true even for patients with rare and hard-to-treat forms of leukemia. Our Bone Marrow Transplant Program offers dedicated cellular therapy and hematopoietic stem cell transplantation. We also offer phase 1, 2 and 3 clinical trials for relapsed leukemia. These clinical research trials advance the standard of care in pediatric oncology and have led to continuous improvements in leukemia remission and cure rates.

We recognize that childhood leukemia diagnosis and treatment is hard on kids and families, which is why we do our best to make the experience as easy as possible. We perform bone marrow tests under anesthesia to relieve the pain and anxiety for our patients. Our specialized pathologists can perform all the testing needed for bone marrow biopsies right here at the hospital, enabling a quick diagnosis for your child and family. And we offer many other resources (and can connect our patients and families with many more) to help ease the process.

Helpful resources for leukemia

A leukemia diagnosis is difficult to deal with. Here, we offer many resources to support kids with childhood leukemia and their families, from diagnosis through well after treatment has ended. We can also connect families with many other organizations and resources that can help.

  • The Wellness Program at Children’s Hospital Colorado helps kids and their families adjust to a cancer diagnosis. Our Wellness Team members include child life specialists, social workers, art therapists, pediatric psychologists and many others.
  • Our HOPE Survivorship Program (Helping Oncology Patients Excel) is one of the nation’s first programs focused on helping childhood cancer survivors manage potential late effects of their diagnosis or treatment. Once they’re ready, we also help manage their transition to adult medical care.
  • The Children’s Oncology Group runs the largest network of clinical trials for childhood cancer treatment in the world. They also provide education and treatment regimen information on childhood cancers for parents and families.
  • The Leukemia and Lymphoma Society is a national patient advocacy, fundraising and research group focused on blood cancers for patients of all ages.

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