Leukemia - B-CellLast Updated: January 08, 2009 This section has been reviewed and approved by the Cancer.Net Editorial Board, 12/08 Overview
Leukemia is a cancer of the blood cells. Types of leukemia are named after the specific blood cell that becomes cancerous, such as the lymphocytic cells (white blood cells) or the myeloid cells (cells of the bone marrow, the spongy, red tissue in the inner part of large bones). There are four main types of leukemia in adults:
There are other, less common types of leukemia, but they are generally subcategories of one of the four main categories. This section focuses on prolymphocytic leukemia (PLL) and hairy cell leukemia (HCL), which are chronic B-cell leukemias. B cells are a specific type of lymphocyte that normally help to produce antibodies for the immune system. In PLL, large numbers of immature lymphocytes, or prolymphocytes, are present in the blood. This type of leukemia may occur together with CLL, or CLL may transform into PLL. HCL is a slow-growing form of leukemia. It is called “hairy cell” because the abnormal lymphocytes have projections that look like hair when seen under a microscope. As these cells multiply, they accumulate in the bone marrow, blood, and spleen. Because these lymphocytes are abnormal, they do not perform the normal work of lymphocytes in fighting disease and infection, and eventually may crowd out the normal cells. HCL typically responds well to treatment. Statistics In 2009, an estimated 44,790 people of all ages (25,630 men and 19,160 women) in the United States will be diagnosed with leukemia. HCL accounts for 2% of all leukemia cases. An estimated 15,490 people (9,200 men and 6,290 women) in the United States will be diagnosed with CLL. There are no current estimates for PLL. Cancer statistics should be interpreted with caution. These estimates are based on data from thousands of cases of this type of cancer in the United States, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with leukemia. Statistics adapted from the American Cancer Society's publication, Cancer Facts and Figures 2009. Find out more about basic cancer terms used in this section. 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. In general, leukemia can be caused by a hereditary genetic mutation or environmental factors (including smoking, chemical, or radiation exposure). However, many cases of leukemia have unknown causes. The following factors may raise a person’s risk of developing PLL and HCL: Age. HCL occurs primarily in people between 40 and 70. Sex. Men are five times more likely to develop HCL than women. Race. HCL is more common in white people and Ashkenazi Jewish men. PLL and HCL are rare in people of Japanese or Southeast Asian descent. 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.
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:
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 counts of different types of cells in a person's blood. 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. 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). Immunophenotyping. Immunophenotyping is the examination of antigens, a specific type of protein, on the surface of the leukemia cells. Immunophenotyping allows the doctor to confirm the exact type of leukemia. Cytogenetics. Cytogenetics is the examination of the leukemia cells for chromosomal abnormalities. It assists in confirming the diagnosis and may help the doctor determine the person’s prognosis (chance of recovery). Computed tomography (CT or CAT) scan. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. Sometimes, a contrast medium (a special dye) is injected into a patient’s vein to provide better detail. A CT scan also shows enlarged lymph nodes or a swollen spleen. To learn more about what to expect during common diagnostic tests, read Cancer.Net: Tests and Procedures. To learn about the terms used in this section, read the Cancer.Net Feature: Cancer Terms to Know: Newly Diagnosed. Staging
Staging is a way of describing a cancer, such as where it is located, if or where it has spread, and if it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the cancer's stage, so staging may not be complete until all of the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis. There are different stage descriptions for different types of cancer. Unlike most solid tumors, HCL and PLL do not have a formal staging system. 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. This section outlines treatments that are the standard of care (the best treatments available) for this specific type of cancer. Patients are also encouraged to consider clinical trials as a treatment option when making treatment plan decisions. A clinical trial is a research study to test a new treatment to prove it is safe, effective, and possibly better than standard treatment. Your doctor can help you review all treatment options. For more information, visit the Clinical Trials section. The goal of treatment for a blood cancer is to bring about a remission of the disease. A complete remission means the doctor can find no evidence of the disease. Treatment options for B-cell leukemia include chemotherapy, monoclonal antibodies, surgery, stem cell transplantation, and biologic therapy. Each option is described below in more detail. Chemotherapy Chemotherapy is the use of drugs to kill cancer cells. Systemic chemotherapy is delivered through the bloodstream, targeting cancer cells throughout the body. The side effects of chemotherapy depend on the individual and the dose used, but can include fatigue, risk of infection, nausea and vomiting, loss of appetite, and diarrhea. These side effects usually go away once treatment is finished. Drugs that are used to treat HCL include cladribine (Leustatin), pentostatin (Nipent), and recombinant interferon alpha (Alferon N, Intron A, Roferon-A,). In most people with HCL, both cladribine and pentostatin produce remissions that last for many years and are the standard initial therapy for the disease. If the initial response period was long, these drugs can be successful again in treating HCL if it returns (comes back after treatment). PLL is treated with combination chemotherapy, meaning more than one drug is used. Several regimens may be used. The regimens are selected according to the type of chemotherapy the patient may have received previously and any associated side effects. The medications used to treat cancer are continually being evaluated. Talking with your doctor is often the best way to learn about the medications prescribed for you, their purpose, and their potential side effects or interactions with other medications. Learn more about your prescriptions through Cancer.Net’s Drug Information Resources, which provides links to searchable drug databases. 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 be appropriate in some people. 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. Transplantation is a higher-risk procedure and is not used frequently in people with B-cell leukemia because it is not a consistently effective therapy for these diseases and because many patients with this disease are older and the risks of the procedure are higher. Before recommending transplantation, doctors will talk with the patient about the risks of this treatment and consider several other factors, such as the type of cancer, results of any previous treatment, and patient’s age and general health. There are two types of stem cell transplantation depending on the source of the replacement blood stem cells: allogeneic (ALLO) and autologous (AUTO). In an ALLO transplant, stem cells are obtained from a donor whose tissue matches the patient’s on a genetic level; this testing is called HLA-typing. Most often, a patient’s brother or sister serves as the donor, although unrelated donors can serve as the donor too. Millions of people worldwide have volunteered to donate stem cells for patients who do not have matched family members; matches can be made by searching a computer registry. In addition, a donation of stem cells derived from umbilical cord blood is sometimes considered if family donors are not available. ALLO transplantation is sometimes considered for younger patients with PLL when chemotherapy was not effective. In an AUTO transplant, the patient’s own stem cells are used. The stem cells are obtained from the patient when he or she is in remission from previous treatment. The stem cells are then frozen until they are needed, usually after the high-dose treatment (explained below) is completed. AUTO transplantation is rarely considered for patients with PLL or HCL. Learn more by reading the Cancer.Net Feature series Understanding Bone Marrow and Stem Cell Transplantation. Biologic therapy Biologic therapy, or immunotherapy, is designed to boost the body’s natural defense to fight the cancer. It uses materials either made by the body or in a laboratory to bolster, target, and restore immune system function. To learn about the terms used in this section, read the Cancer.Net Feature: Cancer Terms to Know: During Treatment. Clinical Trials Resources
Doctors and scientists are always looking for better ways to treat patients with B-cell leukemia. A clinical trial is a way to test a new treatment to prove that it is safe, effective, and possibly better than a standard treatment. Patients who participate in clinical trials are among the first to receive new treatments before they are widely available. However, there is no guarantee that the new treatment will be safe, effective, or better than a standard treatment. Patients decide to participate in clinical trials for many reasons. For some patients, a clinical trial is the best treatment option available. Because standard treatments are not perfect, patients are often willing to face the added uncertainty of a clinical trial in the hope of a better result. Other patients volunteer for clinical trials because they know that finding new drugs and other therapies is the only way to make progress in treating B-cell leukemia. Even if they do not benefit directly from the clinical trial, their participation may benefit future patients with B-cell leukemia. To join a clinical trial, patients must complete a learning process known as informed consent. During informed consent, the doctor should list all of the patient’s options, so the person understands how the new treatment differs from the standard treatment. The doctor must also list all of the risks of the new treatment, which may or may not be different from the risks of standard treatment. Finally, the doctor must explain what will be required of each patient in order to participate in the clinical trial, including the number of doctor visits, tests, and the schedule of treatment. Learn more about Clinical Trials, including patient safety, phases of a clinical trial, deciding to participate in a clinical trial, questions to ask the research team, and links to find cancer clinical trials. Side Effects
Cancer and its treatment can cause a variety of side effects. However, doctors have made major strides in recent years in reducing pain, nausea and vomiting, and other physical side effects of cancer treatments. Many treatments used today are less intensive but as effective as treatments used in the past. Doctors also have many ways to provide relief to patients when such side effects do occur. Fear of treatment side effects is common after a diagnosis of cancer, but it may be helpful to know that preventing and controlling side effects is a major focus of your health-care team. Before treatment begins, talk with your doctor about possible side effects of the specific treatments you will be receiving. The specific side effects that can occur depend on a variety of factors, including the type of cancer, its location, the individual treatment plan (including the length and dosage of treatment), and the person’s overall health. Ask your doctor which side effects are most likely to happen (and which are not), when side effects are likely to occur, and how they will be addressed by the health-care team if they do happen. Also, be sure to communicate with the doctor about side effects you experience during and after treatment. For more information on the most common side effects of cancer and different treatments, along with ways to prevent or control them, visit Cancer.Net’s section on Managing Side Effects, based on ASCO’s curriculum. In addition to physical side effects, there may be psychosocial (emotional and social) effects as well. Learn more about the importance of addressing these needs in Cancer.Net’s section on Caring for the Whole Patient. For more information on late effects or long-term side effects, please read the After Treatment section or talk with your doctor. After Treatment
After treatment for B-cell leukemia ends, talk with your doctor about developing a follow-up care plan. This plan may include regular physical examinations, blood tests, bone marrow biopsies, and possibly scans or other imaging studies to monitor your recovery for the coming months and years. People experiencing a long-term remission are encouraged to follow cancer screening recommendations for the general population. Several long-term side effects from leukemia treatment may occur:
People recovering from B-cell leukemia are encouraged to follow established guidelines for good health, such as maintaining a healthy weight, not smoking, eating a balanced diet, and having recommended cancer screening tests. Talk with your doctor to develop a plan that is best for your needs. Moderate physical activity can help rebuild your strength and energy level. Your doctor can help you create an appropriate exercise plan based upon your needs, physical abilities, and fitness level. Learn more about Healthy Living After Cancer. To learn about the terms used in this section, read the Cancer.Net Feature: Cancer Terms to Know: After Treatment. Current Research
Research for B-cell leukemia is ongoing. The following advances may still be under investigation in clinical trials and may not be approved or available at this time. Always discuss all diagnostic and treatment options with your doctor. New therapies are being tested in clinical trials, including those that use angiogenesis inhibitors and monoclonal antibodies. Angiogenesis inhibitors prevent new blood vessel formation and starve the tumor of oxygen and nutrients. Monoclonal antibodies target proteins that are present in unusually large amounts on the surface of cancer cells. BL22 and LMB-2 are monoclonal antibodies that are linked to toxins; they are designed to attach to the surface proteins of leukemia cells. Doctors are using these and other monoclonal antibodies in clinical trials for people with HCL whose cancer is no longer responding to other treatments. Questions to Ask the Doctor
Regular communication with your doctor is important for making informed decisions about your health care. Consider asking the following questions of your doctor:
Patient Information Resources
The Leukemia & Lymphoma Society Leukemia Research Foundation National Organization for Rare Disorders (NORD) Rare Cancer Alliance American Society for Blood and Marrow Transplantation Blood and Marrow Transplant Information Network National Bone Marrow Transplant Link National Marrow Donor Program View all of Cancer.Net's Patient Information Resources. |
