Introduction
Childhood leukemia is a common form of cancer in children. However, the occurrence of leukemia in infants less than one year of age is rare. The number of reported cases of infant leukemia worldwide is very few and forms only two to five percent of reported cancers. Females have a higher incidence of developing infant leukemia. Infants developing leukemia cannot be cured completely. This article provides detailed insights into infant leukemia.
What Is Leukemia in Infants?
Leukemia is a blood cancer that affects the formation of blood cells in the bone marrow. Healthy infants can produce white blood cells (WBCs) that are adequate to fight off infection and illness. However, infants developing leukemia form a large amount of white blood cells. Since white blood cells form rapidly, the production of other blood cells, such as red blood cells (RBC) and platelets, is disrupted.
What Are the Types of Leukemia in Infants?
There are two types of leukemia in infants and are:
-
Acute Lymphocytic Leukemia: It occurs due to the immune system and affects immature white blood cells known as lymphocytes. The incidence of acute lymphocytic leukemia in infants is less than in children.
-
Acute Myeloid Leukemia: It has its origin within the bone marrow. As the blood cells increase, they spread within the bloodstream and body. The incidence of acute myeloid leukemia is twice that of children.
Why Does Leukemia Occur in Infants?
Scientific studies were unable to determine the cause of leukemia in infants. Although the condition is rare, few studies suggest genetics play an important role in leukemia development. Another study suggests environmental factors during pregnancy could cause leukemia in infants, but this theory needs to be investigated. Maternal factors like marijuana use or paternal smoking during or one month before pregnancy could cause leukemia in infants. However, a few risk factors for infant leukemia are:
-
Diseases affecting the immune system.
-
Genetic conditions like Li-Fraumeni syndrome or Down syndrome. Almost 20 percent of infants with this genetic disorder develop infant leukemia.
-
Siblings or relatives with leukemia.
What Are the Signs of Leukemia in Infants?
In older children, symptoms of leukemia are mild and may resemble the flu. However, infants fall sick and develop severe symptoms. The signs and symptoms that develop in infant leukemia are:
-
Elevated WBC Count: Infants with high WBC develop fever, swollen lymph nodes, fatigue, trouble gaining weight, difficulty breathing, and weight loss.
-
Enlarged Liver or Spleen: Liver damage can cause jaundice, leading to yellowing of skin and eyes. Vomiting and easy bruising are other symptoms.
-
Nervous System Issues: When leukemia attacks the infant’s system, the child finds difficulty staying awake and exhibits strange limb movements. Other features include bulging fontanelle, papilledema, retinal hemorrhage, decreased consciousness, and seizures.
-
Leukemia Spreading to Skin: The infant’s skin develops rashes known as leukemic cutis in the face, legs, or upper body. The rashes may be skin-colored, brown, or purplish and are termed blueberry muffin rash. Skin manifestations are more common in acute myeloid leukemia than in acute lymphocytic leukemia. Infant leukemia with skin involvement has a poor prognosis and a higher relapse rate.
-
Other Symptoms: In infants with leukemia, muscle aches, pain, or discomfort are common phenomena. As a result, the baby can scream, cry, or show distress. Infants have trouble eating and sleeping longer than healthy infants.
If the infants develop any of the above symptoms, healthcare professionals must be consulted immediately.
How to Diagnose Leukemia in Infants?
-
Clinical Examination - This is done by looking at the symptoms and their duration, which may aid in diagnosis. Skin rash, bruising, or swollen lymph nodes is a sign of leukemia. A family history of the disease is necessary as the condition can be inherited.
-
Laboratory Investigations - Doctors suggest several blood tests and laboratory tests to confirm the diagnosis of leukemia. A complete blood count with detailed RBC, WBC, and platelet levels is required. The drawn blood is visualized under a microscope to detect an abnormality. Leukemic infants will have elevated WBCs and abnormal cells.
-
Biopsy - If any abnormality is found in blood tests, then a biopsy of bone marrow is ordered. The procedure is performed under anesthesia, and a needle is inserted into the spine for the collection of bone marrow cells and a piece of bone. It helps confirm leukemia in infants.
What Is the Treatment for Leukemia in Infants?
Treatment of leukemia in infants varies from that of adults and children.
-
Standard Therapy - Infants cannot tolerate standard treatment of leukemia: radiation and medications. The standard therapy would lead to neurological damage in infants. Treatment also differs depending on the type of leukemia and the infant's response.
-
Chemotherapy - Most infants with leukemia are given chemotherapy. Chemotherapy in infants is given in two phases and are induction and consolidation. During the induction phase, intense chemotherapy is provided to infants until leukemia goes into remission. Consolidation chemotherapy begins when leukemia enters remission; a smaller dose of chemotherapy is given to kill the remaining cancer cells.
-
Advanced Interventions - Since the relapse rate for leukemia in infants is more than 50 percent, additional treatments are required. Bone marrow transplants are performed following consolidation. Consolidation, along with killing remaining cancer cells, decreases damaged bone marrow cells and suppresses the immune system to prevent rejection of implants. Gemtuzumab is under trial and could be used as chemotherapy treatment for leukemia due to its efficacy.
-
Bone Marrow Transplantation - This procedure for infants is performed in a hospital setting. A tube is inserted into a vein close to the heart, and stem cells are injected into it. The child is monitored when new stem cells form to avoid the risk of infection.
What Is the Prognosis for Leukemia in Infants?
Leukemia in infants is more challenging to treat as it spreads faster, leading to poor prognosis. Infants below one year have a low survival rate. Bone marrow relapse is common, but other symptoms like combined relapse, extramedullary relapse, and toxic death are common in infants. A high WBC count in infants also indicates their poor survival. However, newer treatment approaches are being evaluated to cure leukemia in infants.
Conclusion
Leukemia is an aggressive cancer in infants and has very few reported cases worldwide. The symptoms are more aggressive in infant leukemia and are difficult to treat. Most infants are treated with chemotherapy and bone marrow transplants. However, there is a higher chance of relapse, leading to a poor prognosis.
