CancerQuest | Section Summary: Leukemia

Introduction

The cellular component of blood contains red blood cells, white blood cells, and platelets.
Leukemia is characterized by an increase in the number of white cells in the blood and bone marrow.

White Blood Cells

There are five types of white blood cells or leukocytes.
Leukocytes play an important role in our body's immune system.
All blood cells form from hematopoietic stem cells.
Blood cell precursors mature in the bone marrow before entering the circulating blood stream.
Disruption of the cell maturation process is central to the development of leukemia.

Types of Leukemia

Leukemia is divided into 4 main categories based on the affected cell type:
- Acute lymphoblastic or myeloid leukemia (ALL and AML)
- Chronic lymphoid or myeloid leukemia (CLL and CML)
Acute leukemias are generally aggressive whereas chronic disorders exhibit a slower progression.

Risk Factors

The risk of developing most types of leukemia increases steadily with age.
Secondary AML can develop following chemotherapy treatment.
Leukemia occurs more frequently in white males than in any other population.
Children with Down syndrome (DS) have a roughly 20-fold increased risk of developing childhood leukemia compared to children without DS.
Exposure to ionizing radiation increases the risk for leukemia.
The Human T-cell Leukemia Virus Type 1 (HTLV-1) has been linked to the development of Adult T-cell Leukemia/Lymphoma.

Symptoms

Paleness, tiredness, shortness of breath, excessive bleeding, and increased susceptibility to infections.
Swelling of the lymph nodes, spleen, and liver.

Detection and Diagnosis

Tumor Biology

Many genetic changes occur in cancer. Details can be found in the Mutation section.

Treatment

Leukemia treatments include: chemotherapy, immunotherapy, radiation therapy, stem cell transplantation and surgery.