General Information About Childhood Hodgkin Lymphoma

Childhood Hodgkin lymphoma is a disease in which malignant (cancer) cells form in the lymph system.

Childhood Hodgkin lymphoma is a type of cancer that develops in the lymph system, part of the body's immune system. The lymph system is made up of the following:

• Lymph: Colorless, watery fluid that travels through the lymph system and carries white blood cells called lymphocytes. Lymphocytes protect the body against infections and the growth of tumors.

• Lymph vessels: A network of thin tubes that collect lymph from different parts of the body and return it to the bloodstream.

• Lymph nodes: Small, bean-shaped structures that filter lymph and store white blood cells that help fight infection and disease. Lymph nodes are located along the network of lymph vessels found throughout the body. Clusters of lymph nodes are found in the underarm, pelvis, neck, abdomen, and groin.

• Spleen: An organ that makes lymphocytes, filters the blood, stores blood cells, and destroys old blood cells. The spleen is on the left side of the abdomen near the stomach.

• Thymus: An organ in which lymphocytes grow and multiply. The thymus is in the chest behind the breastbone.

• Tonsils: Two small masses of lymph tissue at the back of the throat. The tonsils make lymphocytes.

• Bone marrow: The soft, spongy tissue in the center of large bones. Bone marrow makes white blood cells, red blood cells, and platelets.

Because lymph tissue is found throughout the body, Hodgkin lymphoma can start in almost any part of the body and spread to almost any tissue or organ in the body.

Lymphomas are divided into two general types: Hodgkin lymphoma and non-Hodgkin lymphoma. (See the PDQ summary on Childhood Non-Hodgkin Lymphoma Treatment for more information.)

Hodgkin lymphoma can occur in both children and adults; however, treatment for children may be different than treatment for adults. (See the PDQ summary on Adult Hodgkin Lymphoma Treatment for more information.)

There are two types of childhood Hodgkin lymphoma.

The two types of childhood Hodgkin lymphoma are:

• Classical Hodgkin lymphoma.

• Nodular lymphocyte-predominant Hodgkin lymphoma.

Classical Hodgkin lymphoma is divided into four subtypes, based on how the cancer cells look under a microscope:

• Lymphocyte-rich classical Hodgkin lymphoma.

• Nodular sclerosis Hodgkin lymphoma.

• Mixed cellularity Hodgkin lymphoma.

• Lymphocyte-depleted Hodgkin lymphoma.

Age, gender, and Epstein-Barr virus infection can affect the risk of developing childhood Hodgkin lymphoma.

Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor. Risk factors for childhood Hodgkin lymphoma include the following:

• Being between the ages of 15 and 19. At these ages, Hodgkin lymphoma is slightly more common in girls than in boys. In children younger than 5 years, it is more common in boys than in girls.

• Being infected with the Epstein-Barr virus.

• Having a brother or sister with Hodgkin lymphoma.

Possible signs of childhood Hodgkin lymphoma include swollen lymph nodes, fever, night sweats, and weight loss.

These and other symptoms may be caused by childhood Hodgkin lymphoma or by other conditions. A doctor should be consulted if any of the following problems occur:

• Painless, swollen lymph nodes in the neck, chest, underarm, or groin.

• Fever.

• Night sweats.

• Weight loss for no known reason.

• Itchy skin.

Tests that examine the lymph system are used to detect (find) and diagnose childhood Hodgkin lymphoma.

The following tests and procedures may be used:

• Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.

• Lymph node biopsy: The removal of all or part of a lymph node. One of the following types of biopsies may be done:
  • Excisional biopsy: The removal of an entire lymph node.
  • Incisional biopsy: The removal of part of a lymph node.
  • Core biopsy: The removal of tissue from a lymph node using a wide needle.
  • Fine-needle aspiration (FNA) biopsy: The removal of tissue from a lymph node using a thin needle.

  A pathologist views the tissue under a microscope to look for cancer cells, especially Reed-Sternberg cells. Reed-Sternberg cells are common in classical Hodgkin lymphoma.

  Reed-Sternberg cell. Reed-Sternberg cells are large, abnormal lymphocytes that may contain more than one nucleus. These cells are found in Hodgkin lymphoma. | View a Larger Version

• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.

• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.

• Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:
  • The number of red blood cells, white blood cells, and platelets.
  • The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
  • The portion of the blood sample made up of red blood cells.

  Complete blood count (CBC). Blood is collected by inserting a needle into a vein and allowing the blood to flow into a tube. The blood sample is sent to the laboratory and the red blood cells, white blood cells, and platelets are counted. The CBC is used to test for, diagnose, and monitor many different conditions. | View a Larger Version

• Sedimentation rate: A procedure in which a sample of blood is drawn and checked for the rate at which the red blood cells settle to the bottom of the test tube.

• Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.

• PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.

• Immunophenotyping: A test in which the cells in a sample of blood or bone marrow are looked at under a microscope to find out the type of malignant (cancerous) lymphocytes that are causing the lymphoma.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on the following:

• The stage of the cancer.

• The size of the tumor and how quickly it shrinks after initial treatment.

• The patient's symptoms when diagnosed.

• Certain features of the cancer cells.

• Whether the cancer is newly diagnosed, does not respond to initial treatment, or has recurred (come back).

The treatment options also depend on:

• The child's age and gender.

• The risk of long-term side effects.

Most children and adolescents with newly diagnosed Hodgkin lymphoma can be cured.

Stages of Childhood Hodgkin Lymphoma

After childhood Hodgkin lymphoma has been diagnosed, tests are done to find out if cancer cells have spread within the lymph system or to other parts of the body.

The process used to find out if cancer has spread within the lymph system or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. Treatment is based on the stage and other factors that affect prognosis. The following tests and procedures may be used in the staging process:

• MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI). An MRI of the abdomen and pelvis may be done.

• PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.

• Bone marrow aspiration and biopsy: The removal of bone marrow, blood, and a small piece of bone by inserting a hollow needle into the hipbone or breastbone. A pathologist views the bone marrow, blood, and bone under a microscope to look for abnormal cells.

  Bone marrow aspiration and biopsy. After a small area of skin is numbed, a Jamshidi needle (a long, hollow needle) is inserted into the patient’s hip bone. Samples of blood, bone, and bone marrow are removed for examination under a microscope. | View a Larger Version

There are three ways that cancer spreads in the body.

The three ways that cancer spreads in the body are:

• Through tissue. Cancer invades the surrounding normal tissue.

• Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.

• Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.

When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.

Stages of childhood Hodgkin lymphoma may include A, B, E, and S.

Childhood Hodgkin lymphoma may be described as follows:

• A: The patient has no symptoms.

• B: The patient has symptoms such as fever, weight loss, or night sweats.

• E: Cancer is found in an organ or tissue that is not part of the lymph system but which may be next to an involved area of the lymph system.

• S: Cancer is found in the spleen.

The following stages are used for childhood Hodgkin lymphoma:

Stage I

Stage I is divided into stage I and stage IE.

• Stage I: Cancer is found in one or more lymph nodes in one lymph node group.

• Stage IE: Cancer is found outside the lymph nodes in one organ or area.

Stage II

Stage II is divided into stage II and stage IIE.

• Stage II childhood Hodgkin lymphoma. Cancer is found in two or more lymph node groups, and both are either above (a) or below (b) the diaphragm. | View a Larger Version

  Stage II: Cancer is found in two or more lymph node groups above or below the diaphragm (the thin muscle below the lungs that helps breathing and separates the chest from the abdomen).

• Stage IIE childhood Hodgkin lymphoma. Cancer is found in one or more lymph node groups above or below the diaphragm and outside the lymph nodes in a nearby organ or area (a). | View a Larger Version

  Stage IIE: Cancer is found in one or more lymph node groups above or below the diaphragm and outside the lymph nodes in a nearby organ or area.

Stage III

Stage III is divided into stage III, stage IIIE, stage IIIS, and stage IIIE+S.

• Stage III:Cancer is found in one or more lymph node groups above and below the diaphragm (the thin muscle below the lungs that helps breathing and separates the chest from the abdomen).

• Stage IIIE: Cancer is found in lymph node groups above and below the diaphragm and outside the lymph nodes in a nearby organ or area.

• Stage IIIS: Cancer is found in lymph node groups above and below the diaphragm, and in the spleen.

• Stage IIIE+S: Cancer is found in lymph node groups above and below the diaphragm, outside the lymph nodes in a nearby organ or area, and in the spleen.

Stage IV

In stage IV, the cancer:

• is found outside the lymph nodes throughout one or more organs, and may be in lymph nodes near those organs; or

• is found outside the lymph nodes in one organ and has spread to lymph nodes far away from that organ; or

• is found in the lung, liver, or bone marrow.

Untreated, classical Hodgkin lymphoma is divided into risk groups.

Untreated, classical childhood Hodgkin lymphoma is divided into risk groups based on the bulk of the tumor (tumors that are 5 centimeters or larger are considered "bulky") and whether the patient has "b" symptoms (fever, weight loss, or night sweats). Treatment is based on the risk group.

• Low-risk disease:
  • Patients with stage I or stage II disease; and
  • No bulky tumors or "b" symptoms.

• Intermediate-risk disease:
  • Patients with stage I or stage II disease, with bulky tumors, or with "b" symptoms; or
  • Patients with stage III or stage IV disease without "b" symptoms.

• High-risk disease: Patients with stage III or stage IV disease with "b" symptoms.

After initial chemotherapy, a PET scan may be done.

A PET scan may be done after one or two cycles of chemotherapy and again after chemotherapy ends, to find out how well the chemotherapy worked.

Primary Progressive/Recurrent Hodgkin Lymphoma in Children and Adolescents

Primary progressive Hodgkin lymphoma is lymphoma that continues to grow or spread during treatment. Recurrent Hodgkin lymphoma is cancer that has recurred (come back) after it has been treated. The lymphoma may come back in the lymph system or in other parts of the body, such as the lungs, liver, bones, or bone marrow.

Treatment Option Overview

There are different types of treatment for children with Hodgkin lymphoma.

Different types of treatment are available for children with Hodgkin lymphoma. Some treatments are standard and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.

Because cancer in children is rare, taking part in a clinical trial should be considered. Some clinical trials are open only to patients who have not started treatment.

Children with Hodgkin lymphoma should have their treatment planned by a team of health care providers with expertise in treating childhood cancer.

Treatment will be overseen by a pediatric oncologist, a doctor who specializes in treating children with cancer. The pediatric oncologist works with other pediatric health care providers who are experts in treating children with Hodgkin lymphoma and who specialize in certain areas of medicine. These may include the following specialists:

• Medical oncologist/hematologist.

• Pediatric surgeon.

• Radiation oncologist.

• Endocrinologist.

• Pediatric nurse specialist.

• Rehabilitation specialist.

• Psychologist.

• Social worker.

Three types of standard treatment are used:

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). Combination chemotherapy is treatment using more than one anticancer drug. The way the chemotherapy is given depends on the type and stage of the cancer being treated.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Targeted therapy

Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells without harming normal cells. One type of targeted therapy being used in the treatment of childhood Hodgkin lymphoma is monoclonal antibody therapy.

Monoclonal antibody therapy is a cancer treatment that uses antibodies made in the laboratory from a single type of immune system cell. These antibodies can identify substances on cancer cells or normal substances that may help cancer cells grow. The antibodies attach to the substances and kill the cancer cells, block their growth, or keep them from spreading. Monoclonal antibodies are given by infusion. They may be used alone or to carry drugs, toxins, or radioactive material directly to cancer cells.

New types of treatment are being tested in clinical trials.

This summary section describes treatments that are being studied in clinical trials. It may not mention every new treatment being studied. Information about clinical trials is available from the NCI Web site.

High-dose chemotherapy with stem cell transplant

High-dose chemotherapy with stem cell transplant is a way of giving high doses of chemotherapy and replacing blood-forming cells destroyed by the cancer treatment. Stem cells (immature blood cells) are removed from the blood or bone marrow of the patient or a donor and are frozen and stored. After the chemotherapy is completed, the stored stem cells are thawed and given back to the patient through an infusion. These reinfused stem cells grow into (and restore) the body's blood cells.

Surgery

Surgery may be done to remove as much of the tumor as possible.

Patients may want to think about taking part in a clinical trial.

For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.

Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.

Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.

Patients can enter clinical trials before, during, or after starting their cancer treatment.

Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.

Clinical trials are taking place in many parts of the country. See the Treatment Options section that follows for links to current treatment clinical trials. These have been retrieved from NCI's listing of clinical trials.

Follow-up tests may be needed.

Some of the tests that were done to diagnose the cancer or to find out the stage of the cancer may be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue, change, or stop treatment may be based on the results of these tests. This is sometimes called re-staging.

Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.

After one or two cycles of chemotherapy for childhood Hodgkin lymphoma, a PET scan may be done to see how well the lymphoma is responding to treatment. Re-staging is done after chemotherapy ends.

Treatment Options for Children and Adolescents with Hodgkin Lymphoma

A link to a list of current clinical trials is included for each treatment section. For some types or stages of cancer, there may not be any trials listed. Check with your doctor for clinical trials that are not listed here but may be right for you.

Low-Risk Childhood Hodgkin Lymphoma

Treatment of low-risk childhood Hodgkin lymphoma may include the following:

• Combination chemotherapy with low-dose radiation therapy to involved areas.

• A clinical trial of combination chemotherapy with or without low-dose radiation therapy to involved areas.

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with stage I childhood Hodgkin lymphoma and stage II childhood Hodgkin lymphoma. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site.

Intermediate-Risk Childhood Hodgkin Lymphoma

Treatment of intermediate-risk childhood Hodgkin lymphoma may include the following:

• Combination chemotherapy with low-dose radiation therapy to involved areas.

• A clinical trial of new combinations of chemotherapy before low-dose radiation therapy to involved areas.

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with stage I childhood Hodgkin lymphoma, stage II childhood Hodgkin lymphoma, stage III childhood Hodgkin lymphoma and stage IV childhood Hodgkin lymphoma. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site.

High-Risk Childhood Hodgkin Lymphoma

Treatment of high-risk childhood Hodgkin lymphoma may include the following:

• Intensive or high-dose combination chemotherapy with low-dose radiation therapy to involved areas.

• A clinical trial of new combinations of chemotherapy before low-dose radiation therapy to involved areas.

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with stage III childhood Hodgkin lymphoma and stage IV childhood Hodgkin lymphoma. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site.

Nodular Lymphocyte Predominant Childhood Hodgkin Lymphoma

Treatment of nodular lymphocyte predominant childhood Hodgkin lymphoma may include the following:

• Combination chemotherapy with low-dose radiation therapy to involved areas.

• Combination chemotherapy.

• Surgery.

• A clinical trial of surgery to remove a single lymph node.

• A clinical trial of surgery followed by chemotherapy, with or without low-dose radiation therapy to involved areas.

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with childhood nodular lymphocyte predominant Hodgkin lymphoma. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site.

Treatment Options for Primary Progressive/Recurrent Hodgkin Lymphoma in Children and Adolescents

Treatment of primary progressive or recurrent childhood Hodgkin lymphoma may include the following:

• Chemotherapy with low-dose radiation therapy to involved areas for stage I or stage II non-bulky disease. Adolescent patients who have reached full growth may be treated with standard-dose radiation therapy.

• High-dose chemotherapy with stem cell transplant with or without radiation therapy.

• Monoclonal antibody therapy with or without chemotherapy.

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with recurrent/refractory childhood Hodgkin lymphoma. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site.

Late Effects from Childhood and Adolescent Hodgkin Lymphoma Treatment

Children and adolescents may have treatment-related side effects that appear months or years after treatment for Hodgkin lymphoma. Because of these late effects on health and development, regular follow-up exams are important. Late effects may include problems with the following:

• Development of sex organs in males.

• Fertility (ability to have children).

• Thyroid, heart, or lungs.

• An increased risk of developing a second primary cancer.

• Bone growth and development.

There is an increased risk of developing breast cancer for female survivors of Hodgkin lymphoma. This risk depends on the amount of radiation therapy they received during treatment. It is suggested that these patients have a mammogram once a year starting 8 years after treatment or at age 25 years, whichever is later.

The risk of these long-term side effects will be considered when treatment decisions are made. (See the PDQ summary on Late Effects of Treatment for Childhood Cancer for more information.)

To Learn More About Childhood Hodgkin Lymphoma

For more information from the National Cancer Institute about childhood Hodgkin lymphoma, see the following:

• What You Need to Know About™ Hodgkin Lymphoma

• Understanding Cancer Series: The Immune System

• Understanding Cancer Series: Blood Stem Cell Transplants

• Bone Marrow Transplantation and Peripheral Blood Stem Cell Transplantation: Questions and Answers

• Advances in Targeted Therapies

For more childhood cancer information and other general cancer resources from the National Cancer Institute, see the following:

• What You Need to Know About™ Cancer

• Childhood Cancers

• CureSearch for Children's Cancer

• Late Effects of Treatment for Childhood Cancer

• Adolescents and Young Adults with Cancer

• Young People with Cancer: A Handbook for Parents

• Care for Children and Adolescents with Cancer

• Understanding Cancer Series: Cancer

• Cancer Staging

• Coping with Cancer: Supportive and Palliative Care

• Cancer Library

• Information for Survivors/Caregivers/Advocates

Get More Information From NCI

Call 1-800-4-CANCER

For more information, U.S. residents may call the National Cancer Institute's (NCI's) Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 8:00 a.m. to 8:00 p.m., Eastern Time. A trained Cancer Information Specialist is available to answer your questions.

Chat online

The NCI's LiveHelp® online chat service provides Internet users with the ability to chat online with an Information Specialist. The service is available from 8:00 a.m. to 11:00 p.m. Eastern time, Monday through Friday. Information Specialists can help Internet users find information on NCI Web sites and answer questions about cancer.

Write to us

For more information from the NCI, please write to this address:

• NCI Public Inquiries Office

• Suite 3036A

• 6116 Executive Boulevard, MSC8322

• Bethesda, MD 20892-8322

Search the NCI Web site

The NCI Web site provides online access to information on cancer, clinical trials, and other Web sites and organizations that offer support and resources for cancer patients and their families. For a quick search, use the search box in the upper right corner of each Web page. The results for a wide range of search terms will include a list of "Best Bets," editorially chosen Web pages that are most closely related to the search term entered.

There are also many other places to get materials and information about cancer treatment and services. Hospitals in your area may have information about local and regional agencies that have information on finances, getting to and from treatment, receiving care at home, and dealing with problems related to cancer treatment.

Find Publications

The NCI has booklets and other materials for patients, health professionals, and the public. These publications discuss types of cancer, methods of cancer treatment, coping with cancer, and clinical trials. Some publications provide information on tests for cancer, cancer causes and prevention, cancer statistics, and NCI research activities. NCI materials on these and other topics may be ordered online or printed directly from the NCI Publications Locator. These materials can also be ordered by telephone from the Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237).

Changes to This Summary (08/09/2010)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Changes were made to this summary to match those made to the health professional version.

Last Modified: 2010-08-09