What is Cancer?

Cancer develops when cells in part of the body begin to grow out-of-control. Normal body cells grow, divide and die in an orderly fashion. Because cancer cells grow and divide in an out-of-control fashion, they outlive normal cells and continue to form abnormal cells.


Leukemia is a malignant cancer of the bone marrow and blood. It is characterized by the uncontrolled accumulation of blood cells. Leukemia is divided into four categories: myelogenous or lymphocytic, each of which can be acute or chronic. The terms myelogenous or lymphocytic denote the cell type involved.

How Does Leukemia Develop?

Leukemia begins in a single cell in the bone marrow. The cell undergoes a change and becomes a type of leukemia cell. Once the marrow cell undergoes a “leukemic” change, it multiplies into many cells. These leukemia cells grow and survive better than normal cells. In ALL, the original leukemia cell goes on to form about a trillion more leukemia cells. These cells are described as “nonfunctional” because they do not function like normal cells. Over time, they crowd out the normal, healthy cells in the marrow, creating a deficiency of normal platelets, red blood cells, and white blood cells.

What is infant Acute Lymphoblastic Leukemia (infant ALL)?

Infant ALL is a relatively uncommon type of leukemia and occurs in children less than 12 months of age. It occurs in approximately 2-4 percent of cases of childhood ALL. Research has shown that infant ALL represents a distinct, unique biological subtype of leukemia. The prognosis for infants with ALL is much less favorable than for older children with ALL. Treatment of these infants is very difficult and remains a significant challenge.

Possible Causes of Leukemia

Anyone can get leukemia. Leukemia strikes all ages and both sexes. The cause of leukemia is not known.

New Cases

An estimated 218,659 people in the United States are living with leukemia. An estimated 44,240 new cases of leukemia will be diagnosed in the United States this year. About 33 percent of cancers in children aged 0-14 years are leukemia. It is estimated that in 2008, 3,800 children will be diagnosed with leukemia in the United States. The most common form of leukemia in children is ALL. About 2,790 new cases of childhood ALL are expected in 2008.


The five-year survival rate has more than tripled in the past 47 years for patients with leukemia. In 1960-1963, a patient had a 14 percent chance of living five years. By 1996-2003, the overall survival rate was nearly 50 percent. The relative survival rates differ by age at diagnosis, gender, race, and type of leukemia.

The development of effective therapy for ALL is one of the great successes of pediatric oncology. The leukemia death rate for children from 0 to 14 years in the United States has declined about 70 percent over the past three decades. With current therapy, the survival rate for childhood ALL is approximately 80 percent.

Despite significant improvements in therapy, leukemia causes more deaths than any other cancer among children and young adults under age 20. In 2008, about 515 children under the age of 14 are expected to die from leukemia.

The Importance of Research

New approaches to therapy are under study in clinical trials to help a growing number of patients achieve remission and cure. New drugs, new types of immunotherapy, and new approaches to stem cell transplantation are continually being explored to bring new and better treatments to the patient.