Leukemia - EosinophilicLast Updated: September 15, 2009 This section has been reviewed and approved by the Cancer.Net Editorial Board, 09/09 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, which is the spongy tissue inside the larger bones in the body. Abnormalities in the bone marrow cells can cause the overproduction or underproduction of certain blood cells. There are four main types of leukemia in adults:
Eosinophilia is a condition that develops when the bone marrow makes too many eosinophils, a type of white blood cell that is involved in allergic reactions or used to fight certain parasites. Chronic eosinophilic leukemia is a subtype of clonal (from an acquired genetic abnormality) eosinophilia that is sometimes called hypereosinophilic syndrome (HES). This disease is classified as a myeloproliferative disorder (myelo- refers to bone marrow, proliferative means excess). People can also have high numbers of eosinophils without having cancer. For example, sometimes the body makes too many eosinophils in response to an allergen or a parasite. This type of eosinophilia is called secondary eosinophilia and is much more common than eosinophilic leukemia. This section focuses on chronic eosinophilic leukemia. Acute eosinophilic leukemia is rare and is treated similarly to acute myeloid leukemia (AML). For more information, read the guide to Acute Myeloid Leukemia. Statistics Eosinophilic leukemia is rare; no specific statistics are available. 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. Leukemia can be caused by a genetic mutation brought on by heredity or environmental factors (including smoking, chemical, or radiation exposure). However, no specific cause can be identified in most patients with leukemia. The specific cause(s) of eosinophilic leukemia is not known. Symptoms
People with eosinophilic leukemia may experience the following symptoms. Sometimes, people with eosinophilic 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 tests, such as evaluations of the blood and bone marrow, to diagnose eosinophilia. Although a patient’s signs and symptoms may cause a doctor to suspect eosinophilia, 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 main criteria for diagnosing eosinophilic leukemia are:
In addition to a physical examination, the following tests may be used to diagnose eosinophilic leukemia: Blood tests. The diagnosis of eosinophilic leukemia begins with a routine blood test to measure the number of different types of cells in a person's blood, called a complete blood count (CBC). If the blood contains high levels of eosinophils (see criteria above), eosinophilic 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. An increased number of immature cells, known as blasts, indicate an acute rather than a chronic eosinophilic leukemia. If an increased number of eosinophils are found, a molecular genetic analysis should be done to test for a mutation that produces an abnormal protein known as FIP1-like-1/platelet-derived growth factor alpha. This could help decide the type of treatment which should be given (see Treatment). Immunophenotyping. Immunophenotyping is the examination of the proteins on the surface of the leukemic cells and allows the doctor to confirm the exact type of leukemia. Cytogenetics. Cytogenetics is the examination of the leukemic 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 or liver. Evaluation of the heart. People with high eosinophil counts over a long period of time frequently have disturbances in heart function and rhythm. The doctor may recommend an electrocardiogram (ECG or EKG, a test that records the electrical activity of the heart to show whether there are abnormal rhythms or to detect damage) and/or an echocardiogram (a procedure that evaluates the structure and function of the heart using sound waves and an electronic sensor). Learn more about what to expect when having common tests, procedures, and scans. Find out more about common terms used during a diagnosis of cancer. 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, leukemias do not have a formal staging system. Serial blood counts (regular blood tests) are the main indicators used to monitor a person’s recovery from eosinophilic leukemia, as well as the elimination of any symptoms related to the disease and the percentage of immature cells in the bone marrow. Treatment
The treatment of eosinophilic leukemia depends on various factors, including the patient’s overall health. In many cases, a team of doctors will work with the patient to determine the best treatment plan. According to the National Cancer Institute, the best treatment for eosinophilic leukemia remains unclear. Patients are 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. As explained in the Overview, eosinophilic leukemia is classified as a myeloproliferative disorder. General treatments for myeloproliferative disorders include chemotherapy, radiation therapy, surgery, immunotherapy, targeted therapy, steroids, and stem cell/bone marrow transplantation. Usually, myeloproliferative disorders cannot be cured, but treatment helps to control the symptoms. Descriptions of the most common treatment options for myeloproliferative disorders are listed below. 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 a medical oncologist, a doctor who specializes in treating cancer with medication, or a hematologist, a doctor who specializes in blood diseases. 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. Chemotherapy used in treating eosinophilic leukemia include hydroxyurea (Droxia, Hydrea), cyclophosphamide (Clafen, Cytoxan, Neosar), and vincristine (Oncovin). 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. Learn more about chemotherapy and preparing for treatment. 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 by using searchable drug databases. Radiation therapy Radiation therapy is the use of high-energy x-rays or other particles to kill cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. The most common type of radiation therapy is called external-beam radiation therapy, which is radiation given from a machine outside the body. When radiation therapy is given using implants, it is called internal radiation therapy or brachytherapy. Radiation therapy for eosinophilic leukemia is generally used as a palliative treatment (care given to improve a patient’s quality of life by treating symptoms and side effects of the cancer or its treatment). Side effects from radiation therapy may include fatigue, mild skin reactions, upset stomach, and loose bowel movements. Most side effects go away soon after treatment is finished. Learn more about radiation therapy. Surgery Surgery to remove the spleen (splenectomy), which also produces white blood cells, may occasionally be performed. A surgical oncologist is a doctor who specializes in treating cancer using surgery. Learn more about cancer surgery. Immunotherapy Immunotherapy (also called biologic therapy), is designed to boost the body's natural defenses to fight the cancer. It uses materials either made by the body or in a laboratory to bolster, target, or restore immune system function. Recombinant interferon alpha (Alferon N, Roferon-A, Intron A) is a biologic therapy that is occasionally used to treat eosinophilic leukemia. Learn more about immunotherapy. Targeted therapy Targeted therapy is a type of treatment that selectively attacks faulty genes or proteins that contribute to cancer growth and development. In many patients with hypereosinophilic syndrome, the leukemic cells have a specific genetic abnormality or mutation that produces an abnormal protein (known as FIP1-like-1/platelet-derived growth factor alpha) that stimulates the cells to grow. Imatinib mesylate (Gleevec) is a drug which inhibits a number of enzymes called tyrosine kinases and can kill abnormal eosinophils by blocking the function of the FIP1-like-1-platelet-derived growth factor alpha protein. Imatinib is more likely to work if this mutation is present; however, if the mutation is not present, there is still a possibility that the disease will respond to the drug. The main side effects of imatinib include swelling around the eyes, leg swelling and cramping, headache, fatigue, rash, and musculoskeletal (joint) pain. Learn more about targeted treatments. Steroids Steroid medications are used to control some symptoms of eosinophilic leukemia. Stem cell 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 eosinophilic leukemia because it is not a consistently effective treatment for this disease and because many patients with this disease are older and the risks of the procedure are higher. For further information about stem cell transplantation, please refer to the section on bone marrow and stem cell transplantation. Find out more about common terms used during cancer treatment. Clinical Trials Resources
Doctors and scientists are always looking for better ways to treat patients with eosinophilic 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. The clinical trial may be evaluating a new drug, a new combination of existing treatments, a new approach to radiation therapy or surgery, or a new method of treatment or prevention. 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 eosinophilic leukemia. Even if they do not benefit directly from the clinical trial, their participation may benefit future patients with eosinophilic leukemia. Sometimes people have concerns that, by participating in a clinical trial, they may receive no treatment by being given a placebo or a “sugar pill”. The use of placebos in cancer clinical trials is rare. When a placebo is used in a study, it is done with the full knowledge of the participants. Find out more about placebos in cancer clinical trials. To join a clinical trial, patients must participate in a 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. For specific topics being studied for eosinophilic leukemia, learn more in the Current Research section. 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. Learn more about the most common side effects of cancer and different treatments, along with ways to prevent or control them. In addition to physical side effects, there may be psychosocial (emotional and social) effects as well. Learn more about the importance of addressing such needs, including concerns about managing the cost of your medical care. Learn more about late effects or long-term side effects by reading the After Treatment section or talking with your doctor. After Treatment
After treatment for eosinophilic 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. Some cancer treatments may cause long-term side effects.
Talk with your health-care team about the best ways to manage these side effects. People recovering from eosinophilic 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. Find out more about common terms used after cancer treatment is complete. Current Research
Research for eosinophilic leukemia and other myeloproliferative disorders 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. Genetic research. Because this type of disorder is usually associated with a genetic mutation, researchers are searching for specific genetic markers (the presence or absence of specific genes or mutations that can indicate cancer). Expanded use of transplantation. New approaches for stem cell/bone marrow transplantation are being tested. New treatments. Better combinations of chemotherapy and additional treatment combinations are also being explored, as is the drug mepolizumab (Bosatria). Mepolizumab is a humanized monoclonal antibody that binds specifically to human interleukin 5 (hIL-5) and inhibits its activity. Preliminary studies in people have shown that mepolizumab lowers blood eosinophilia in people with allergies and HES and has alleviated some clinical signs and symptoms of HES. 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
In addition to Cancer.Net, there are other sources of information about this type of cancer available online. Cancer.Net maintains a list of national, not-for-profit organizations that may be helpful in finding additional information, services, and support. As always, be sure to talk with your doctor about questions you may have about information you find about this disease. View organizations that offer information on this specific type of cancer. |
