Leukemia – B-Cell

Overview

Leukemia is a cancer of the blood cells. Leukemia begins when normal blood cells change and grow uncontrollably. Blood cells (including red cells that carry oxygen, white cells that fight infection, and platelets that cause blood to clot) are produced in the bone marrow, the spongy tissue inside the larger bones in the body. Types of leukemia are named after the specific blood cell that becomes cancerous, such as the lymphoid cells (white blood cells of the immune system) or the myeloid cells (cells of the bone marrow which develop into cells which fight bacterial infections). There are four main types of leukemia in adults:

• Acute lymphocytic leukemia (ALL)
• Chronic lymphocytic leukemia (CLL)
• Acute myeloid leukemia (AML)
• Chronic myeloid leukemia (CML)

Risk Factors

A risk factor is anything that increases a person’s chance of developing cancer. Some risk factors can be controlled, such as smoking, and some cannot be controlled, such as age and family history. Although risk factors can influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and communicating them to your doctor may help you make more informed lifestyle and health-care choices.

Symptoms

People with B-cell leukemia may experience the following symptoms. Sometimes, people with B-cell leukemia do not show any of these symptoms. Or, these symptoms may be caused by a medical condition that is not cancer. If you are concerned about a symptom on this list, please talk with your doctor.

• Enlarged lymph nodes in PLL. In HCL, hairy cells accumulate more often in the spleen and bone marrow and therefore may not cause noticeable lymph node swelling.
• Tendency to bruise easily
• Slow wound healing
• Weight loss
• Unexplained fatigue

Diagnosis

Doctors use many blood and bone marrow tests to diagnose leukemia and to determine the extent to which it may have spread. Although a patient’s signs and symptoms may cause a doctor to suspect leukemia, it is diagnosed only by blood tests and bone marrow evaluations. Some tests may also determine which treatments may be the most effective. Your doctor may consider these factors when choosing a diagnostic test:

• Age and medical condition
• The type of cancer suspected
• Severity of symptoms
• Previous test results

The following tests may be used to diagnose PLL and HCL:

Blood tests. The diagnosis of PLL or HCL begins with a blood test to measure the numbers of different types of cells in a person’s blood, called a complete blood count (CBC). If the blood contains high levels of white blood cells, B-cell leukemia may be present.
Bone marrow biopsy. In a bone marrow biopsy, a doctor takes a sample of marrow, usually from the back of the patient’s hipbone with a needle after the area has been numbed. The cells from the marrow, along with the cells from the blood, are analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease) to determine the number and type of abnormal cells.

Treatment

The treatment of HCL or PLL depends on whether the disease is causing symptoms, the extent to which the cancer has spread, and the patient’s overall health. In many cases, a team of doctors will work with the patient to determine the best treatment plan.

Chemotherapy

Chemotherapy is the use of drugs to kill cancer cells. Systemic chemotherapy is delivered through the bloodstream, targeting cancer cells throughout the body. Chemotherapy is given by either a medical oncologist, a doctor who specializes in treating cancer with medication, or a hematologist, a doctor who specializes in treating blood disorders. Some people may receive chemotherapy in their doctor’s office; others may go to the hospital. A chemotherapy regimen (schedule) usually consists of a specific number of cycles given over a specific time.

Monoclonal antibodies

Monoclonal antibodies are antibodies directed against specific proteins on the cell surface of the cancer cell. Rituximab (Rituxan) is an antibody directed against the surface protein CD20. BL22 immunotoxin is an antibody attached to a toxin that is designed to attach to the surface protein, CD22, and deliver the toxin to the cancer cell. Both of these have been used in the treatment of HCL that did not go into remission after initial therapy (called refractory or resistant HCL). However, BL22 is not approved by the U.S. Food and Drug Administration (FDA) for the treatment of PLL and is only available in clinical trials. Alemtuzumab (Campath) is an antibody directed against the surface protein CD52 and has been used in the treatment of PLL.

Surgery

Surgery to remove the spleen (splenectomy), which also produces white blood cells, may occasionally be performed. Learn more about cancer surgery.

Stem cell transplantation/bone marrow transplantation

A stem cell transplant is a medical procedure in which diseased bone marrow is replaced by highly specialized cells, called hematopoietic stem cells. Hematopoietic stem cells are found both in the bloodstream and in the bone marrow. Today, this procedure is more commonly called a stem cell transplant, rather than bone marrow transplant, because blood stem cells are typically what is being transplanted, not the actual bone marrow tissue.