Non-Hodgkin's lymphoma

Highlights

Non-Hodgkin’s Lymphoma

The non-Hodgkin’s lymphomas (NHL) are a group of cancers that develop in the body’s lymphatic system. There are many different types of non-Hodgkin’s lymphoma. Most types of NHL involve B cells, while a small percentage involve T cells. Common types of B-cell non-Hodgkin’s lymphomas include diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma.

Prognosis

Non-Hodgkin’s lymphomas are classified as indolent (slow-growing) or aggressive (fast-growing). Aggressive lymphomas, such as DLBCL, are often curable. Indolent lymphomas, such as follicular lymphoma, are more difficult to treat and tend to recur after periods of remission. With the advancement of new treatments and drugs, survival rates for patients with NHL have significantly improved.

Risk Factors

The risk of NHL increases with age, and most patients are diagnosed when they are in their 60s and 70s. NHL can develop, however, in people of any age, including children. People who have had immune system impairment through infections, disease, or exposure to certain types of chemicals appear to have increased risk. Still, people without any known risk factors can develop NHL.

Symptoms

The most common first sign of lymphomas is painless enlargement of one or more lymph node, usually in the neck, armpits, or groin.

More generalized symptoms can include:

Diagnosis

NHL is diagnosed based on the results of physical examination, blood tests, imaging tests, and biopsy. A lymph node biopsy is the definitive test for diagnosing NHL, determining the type of NHL, and distinguishing NHL from Hodgkin’s disease.

Treatment

Radiation and chemotherapy are the main treatments for NHL. Rituximab, a biologic drug, is increasingly being used and may be added to a chemotherapy regimen. For some patients, stem cell or bone marrow transplantation may be an option.

Introduction

Lymphomas are malignancies of the lymph system that are generally subdivided into two groups, Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL). Hodgkin's disease accounts for about 15% of all lymphomas. [For more information, see In-Depth Report #83: Hodgkin's disease.]

Non-Hodgkin's lymphoma is a term for malignancies that range from a very slow disease to an extremely aggressive but curable condition. They have certain features in common.

Lymphatic system
The lymphatic system filters fluid from around cells. It is an important part of the immune system. When people say they have swollen glands in the neck, they are usually referring to enlarged lymph nodes. Common areas where lymph nodes can be easily felt, especially if they are enlarged, include the groin, armpits (axilla), above the clavicle (supraclavicular), in the neck (cervical), and the back of the head just above hairline (occipital).

The Lymphatic System

Lymphomas, such as non-Hodgkin's lymphomas and Hodgkin's disease, represent tumors of the lymphatic system. This system is a network of organs, ducts, and nodes. The lymphatic system interacts with the blood's circulatory system to transport a watery clear fluid called lymph throughout the body. The lymphatic system contains lymphocytes, important cells involved in defending the body against infectious organisms.

Lymphocytes. The lymphatic system is involved in the production and transportation of lymphocytes, white blood cells that are a primary component of the immune system.

Lymph Nodes. In the lymph node, lymphocytes receive their initial exposure to foreign substances (antigens), such as bacteria or other microorganisms, which activate the lymphocytes to produce antibodies, immune system factors that target and attack specific foreign proteins (antigens). The size of a lymph node varies from that of a pinhead to a bean. Most nodes are in clusters located throughout the body. Important node clusters are found in the neck, lower arm, armpit, and groin.

Other Structures in the Lymphatic System. The tonsils and adenoids are secondary organs composed of masses of lymph tissue that also play a role in the lymphatic system. The spleen is another important organ that processes lymphocytes from incoming blood.

Lymph nodes

 Click the icon to see an animation detailing the lymph nodes. 

 Click the icon to see an image of lymph tissue in the head and neck. 

 Click the icon to see an image of the immune system structures. 

Locations of Non-Hodgkin's Lymphomas

Non-Hodgkin's lymphomas occur most often in lymph nodes in the chest, neck, abdomen, tonsils, and the skin. NHLs may also develop in sites other than lymph nodes such as the digestive tract, central nervous system, and around the tonsils.

Non-Hodgkin's Lymphomas Categories

There are more than 30 distinct types of non-Hodgkin's lymphomas. Lymphomas are categorized in a several ways:

B-Cell Lymphomas

Common types of B-cell lymphoma include:

Diffuse Large B-Cell Lymphoma (DLBLC). DLBCL is the most common type of non-Hodgkin’s lymphoma, accounting for about 30% of all NHL cases. It is an aggressive, fast-growing lymphoma that usually affects adults but can also occur in children. DLBCL can occur in lymph nodes or in organs outside of the lymphatic system. DLBCL includes several subtypes such as mediastinal large B-cell lymphoma, intravascular large B-cell lymphoma, and primary effusion lymphoma.

Follicular Lymphoma (FLs). Follicular lymphoma is the second most common type lymphoma, accounting for about 20% of all NHL cases. It is usually indolent (slow growing), but about half of follicular lymphomas transform over time into the aggressive diffuse large B-cell lymphoma.

Mantle Cell Lymphoma. Mantle cell lymphoma is an aggressive type of lymphoma that represent about 7% of NHL cases. It is a difficult type of lymphoma to treat and often does not respond to chemotherapy. It is found in lymph nodes, the spleen, bone marrow, and gastrointestinal system. Mantle cell lymphoma usually develops in men over age 60.

Small Lymphocytic Lymphoma (SLL). SLL is an indolent type of lymphoma that is closely related to B-cell chronic lymphocytic leukemia (CLL). It accounts for about 5% of NHL cases.

Marginal Zone Lymphomas (MZL). MZLs are categorized depending on where the lymphoma is located. Mucosa-associated lymphoid tissue lymphomas (MALT) usually involve the gastrointestinal tract, thyroid, lungs, saliva glands, or skin. MALT is often associated with a history of an autoimmune disorder (such as Sjogren syndrome in the salivary glands or Hashimoto's thyroiditis in the thyroid gland). MALT is also associated with bacterial infection in the stomach (H. pylori ) and can be potentially cured by antibiotics when treated in its early stages. Splenic marginal zone lymphoma affects the spleen, blood, and bone marrow. Nodal marginal zone B-cell lymphoma is a rare type of indolent lymphoma that involves the lymph nodes.

Lymphoplasmacytic Lymphoma. Lymphoplasmacytic lymphoma, also called Waldenstrom's macroglobulinemia or immunocytoma, is a rare type of lymphoma accounting for about 1% of NHL cases. It usually affects older adults and most often involves bone marrow, lymph nodes, and spleen.

Primary Central Nervous System Lymphoma. This lymphoma involves the brain and spinal cord. Although it is generally rare, it is common in people who have AIDS.

Burkitt's Lymphoma. This is one of the most common types of childhood NHL, accounting for about 40% of NHL pediatric cases in the United States. It usually starts in the abdomen and spreads to other organs, including the brain. In African children, it often involves facial bones and is associated with Epstein-Barr infection.

Lymphoblastic Lymphoma. This lymphoma is also common in children, accounting for about 25% of NHL pediatric cases, most often boys. It is associated with a large mediastinal mass (occurring in chest cavity between the lungs) and carries a high risk for spreading to bone marrow, the brain, and other lymph nodes.

Risk Factors

Non-Hodgkin’s lymphoma is the seventh most common cancer in the United States. Each year, about 70,000 Americans are diagnosed with non-Hodgkin's lymphomas, and about 20,000 people die of the disease. Since the 1970s, NHL incidence rates have doubled. Part of the reason for this dramatic rise may be due to AIDS, which increases the risk for high-grade lymphomas.

The cause of non-Hodgkin’s lymphoma is unknown, but certain factors may increase a person’s risk of developing this cancer.

Age

Non-Hodgkin’s lymphoma can develop in people of all ages, including children, but it is most common in adults. The most common types of NHL usually appear in people in their 60s and 70s.

Gender

NHL is more common in men than women.

Race

Overall, the risk for NHL is slightly higher in Caucasians than in African-Americans and Asian Americans.

Family History

People who have close family relatives who have developed NHL may be at increased risk for this cancer. However, no definitive hereditary or genetic link has been established.

Infections

Viral or bacterial infections may play a role in some lymphomas. These include:

Immune System Deficiency Disorders

Patients with diseases or conditions that affect the immune system may be at higher risk for lymphomas:

Autoimmune Disorders

Patients with a history of autoimmune diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus, Hashimoto's thyroiditis, Crohn's disease, and Sjogren syndrome, are at an increased risk for certain NHLs, such as marginal zone lymphomas.

Chemical Exposure

Overexposure to a number of industrial and agricultural chemicals (such as pesticides, herbicides, and petrochemicals) has been linked to an increased risk for lymphomas. The data, however, are not consistent.

Researchers are also investigating whether some chemotherapy drugs may increase the risk for later developing non-Hodgkin’s lymphoma. At this point, it is not clear whether it is these drugs or the other cancers themselves that increase risk. Other types of drugs, such as tumor necrosis factor (TNF) inhibitors that are used to treat autoimmune disorders, are also being studied as possible risk factors for lymphomas.

Radiation Exposure

People who have had radiation treatment for cancer, such as Hodgkin’s disease, appear to have an increased risk for later developing non-Hodgkin’s disease. The risk may be higher for patients treated with both chemotherapy and radiation.

Survivors of nuclear reactor disasters have an increased risk of developing NHL, as well as other types of cancers.

Lifestyle Factors

Lifestyle does not seem to be a major risk factor for NHL. Some studies have suggested that obesity may increase risk, but this association is not definite. Other studies have investigated the role of diet. Although some research has indicated an increased risk for diets high in consumption of red meat and lower risk for diets high in vegetables, the association remains speculative. There is no evidence that smoking increases the risk for NHL itself, although it has been linked with high-grade and follicular NHLs in people with lymphoma.

Symptoms

The most common first sign of lymphoma is painless enlargement of one or more lymph node, usually in the neck, armpits, or groin. These enlarged lymph nodes may cause discomfort depending on where they are located. For example, abdominal tumors may cause stomach distention or pain, while lymph nodes in the chest may cause coughing or difficulty breathing. Patients should see their doctors if these symptoms do not go away within 2 - 3 weeks.

Sometimes patients with NHL do not experience any symptoms, or symptoms may not appear until the cancer is very advanced. Enlarged lymph nodes can also be caused by many noncancerous conditions, such as infections.

Neck lump
The most common lumps or swellings in the neck are enlarged lymph nodes. They can be caused by bacterial or viral infections, cancer, and other rare causes.

Systemic and B Symptoms

Lymphomas sometimes cause systemic symptoms -- symptoms that affect the whole body, rather than a specific location. Some systemic generalized symptoms are referred to as B symptoms. Patients who have B symptoms have a more severe condition than asymptomatic patients with the same cancer stage or tumor location or size.

B systemic symptoms include:

Diagnosis

The doctor will first ask questions about the patient's medical history and perform a physical examination to detect any node enlargements. If these steps point to lymphoma, additional tests will be done to rule out other diseases or to confirm the diagnosis and extent of the lymphoma.

Physical Examination

The doctor will examine not only the affected lymph nodes but also the surrounding tissues and other lymph node areas for signs of infection, skin injuries, or tumors. The consistency of the node sometimes indicates certain conditions. For example, a stony, hard node is often a sign of cancer, usually one that has metastasized (spread to another part of the body). A firm, rubbery node may indicate lymphoma. Soft tender nodes suggest infection or inflammatory conditions.

Biopsy

A biopsy is the most important test for diagnosing non-Hodgkin’s lymphoma and determining the subtype. Tissue samples retrieved from biopsy are examined under a microscope to find out if the cell type involved is indicative of Hodgkin’s disease or non-Hodgkin’s. (Hodgkin’s disease is marked by the presence of Reed-Sternberg cells, which are not found in non-Hodgkin’s lymphomas.) Sometimes a doctor may choose to wait and observe the involved lymph nodes, which will usually go away on their own if a temporary infection is causing the swelling. (However, some lymphomas may go away and appear to be benign, only to reappear at a later time.)

The Procedure. The type of biopsy performed depends in part on the location and accessibility of the lymph node. The doctor may surgically remove the entire lymph node (excisional biopsy) or a small part of it (incisional biopsy). In some cases, the doctor may use fine needle aspiration to withdraw a small amount of tissue from the lymph node.

Results. Even if biopsies do not show any problems, disease may still be present in some patients. The doctor should continue to observe the patient until swelling or other signs of disease are gone. Biopsied tissue samples should be frozen in case special tests are later required. Such tests may include detection of particular antibodies, genetic and immune factors, and certain markers (substances that may indicate disease) located on the surface of the cells. If lymphoma has been diagnosed, the tissue will be examined for its histology, the cellular structures that will determine the lymphoma type.

Bone Marrow Aspirate and Biopsy

Bone marrow aspirate and biopsy are routinely performed to determine whether the disease has spread. With bone marrow aspirate, bone marrow cells are sucked out through a special needle. A biopsy may be performed before or after the aspiration. In this procedure, a special needle removes a core of the marrow that is structurally intact.


 Click the icon to see an image of bone marrow aspiration. 

Imaging Techniques

Chest X-Ray. A chest x-ray may show lymph nodes in the chest and neck area. It is particularly useful in detecting Hodgkin's disease and enlarged lymph nodes.


 Click the icon to see an image of an x-ray machine. 

Computed Tomography. Computed tomography (CT) scans are much more accurate than x-rays. They can detect abnormalities in the chest and neck area, as well as revealing the extent of the cancer and whether it has spread. CT scans are used to evaluate symptoms and help diagnose lymphomas, help with staging of the disease, monitor response to treatment, and evaluate symptoms. A CT scan is also often used to detect lymphomas in the abdominal and pelvic areas, the brain, and the chest.


 Click the icon to see an image of a CT machine. 

Magnetic Resonance Imaging (MRI). MRIs may be used to detect the spread of the disease to the brain, spine, chest, pelvis, and abdomen.


 Click the icon to see an image of an MRI machine. 

Positron Emission Tomography (PET). PET scans can help predict whether an enlarged lymph node is benign or cancerous. PET scans are more accurate than CT scans or other imaging tests for staging lymphomas. PET scans may also help doctors determine how well a patient has responded to treatment, if any residual cancer exists, and if a patient has achieved remission.

Blood Tests

Blood tests help rule out infection and other diseases. Such tests include a complete blood count to measure the number of white blood cells. In a patient already diagnosed with lymphoma, blood tests that measure the enzyme lactate dehydrogenase are important in determining the prognosis of patients with fast-growing lymphomas. High levels indicate bulkier tumors.

Molecular Diagnostic Tests

Tests of lymphoma's DNA are in use or are being developed to detect particular gene defects that help determine prognosis and response to treatment. Examples of such abnormal genetic arrangements are those that affect normal cell death, resist chemotherapy, or trigger aggressive cancer growth.

Prognosis

Survival rates for NHL vary widely, depending on the lymphoma type, stage, age of the patient, and other variables. According to the American Cancer Society, the overall 5-year relative survival rate for patients with non-Hodgkin’s lymphoma is 67% and the 10-year relative survival rate is 55%. (The relative survival rate estimates the likelihood that a patient will survive a certain number years after diagnosis. It is calculated to exclude the likelihood of death from diseases other than the cancer. The relative survival rate is also referred to as disease-specific survival.)

Because the outlook varies so widely, establishing a definite prognosis is very difficult. For example, patients with very slow growing (indolent) lymphomas can live many years. However, they are usually diagnosed at a late stage, after the cancer has spread, thus reducing the survival rate. Without treatment, aggressive lymphomas are more likely to cause early death, but they are also often curable.

Survival rates for patients with NHL have greatly improved since the early 1990s, especially for patients under age 45. Advances in treatment have contributed to this improvement.

Outlook for Indolent Lymphomas

Follicular lymphomas, the most common indolent (slow-growing) NHLs, are potentially curable in early stages I and II. Unfortunately, however, these slow-growing malignancies produce no symptoms until they are in advanced stages. In most cases, these lymphomas are not diagnosed until they have spread to other sites, including the spleen and bone marrow. In such cases, they are difficult to cure. Predicting outcome for indolent follicular lymphomas is more difficult than for aggressive lymphomas. Even if treatment achieves a response, these tumors almost always recur. Even after relapse, however, the tumors can be treated again if they are still very slow-growing.

In general, the average survival rate for follicular lymphoma is 7 - 10 years after diagnosis, depending on other risk factors. New drug treatments, particularly monoclonal antibodies, have significantly improved survival rates.

Outlook for Aggressive Lymphomas

High-grade aggressive lymphomas are often symptomatic early on and are potentially curable with aggressive treatments. Diffuse large B-cell lymphoma (DLBLC), the most common aggressive non-Hodgkin's lymphomas, while fatal if not treated, is often curable with intensive chemotherapy combinations. If relapse occurs after chemotherapy, it usually does so within 2 years.

Most other aggressive lymphomas respond to aggressive chemotherapy. Some aggressive lymphomas, such as mantle cell lymphoma, are less responsive to standard chemotherapy.

International Prognostic Index

A scoring system called the International Prognostic Index has proved to be fairly accurate for predicting outcome in patients with most aggressive B-cell lymphomas such as DLBCL. It uses five risk factors to help predict survival odds:

Having one or none of these risk factors indicates the best outlook. Two factors indicate a low-to-intermediate likelihood of a poor outlook. Three factors predict an intermediate-to-high likelihood of poor outlooks. Finally, four or five factors pose the highest likelihood of poor survival. However, the International Prognostic Index was developed before the introduction of newer drug therapies like rituximab, which has dramatically helped improve the outcome of patients with DLBCL.

A similar prognostic index has been developed for follicular lymphoma.

Long-Term Complications of Treatments

Medical Problems. The radiation and chemotherapies used in treating NHL can have long-term effects on many organs in the body and can increase the risk for serious illnesses, including heart disease and certain cancers.

Emotional Problems. Depression and anxiety are common in survivors, particularly those who suffer additional medical conditions. Many patients also suffer from fatigue and aches and pains, called somatic symptoms, which have no apparent physical basis.

Treatment

Treatment for non-Hodgkin's lymphoma is highly specific for each patient and is determined by the tumor classification. It includes the following factors:

Staging and Grading

Grading refers to how fast the tumor cells grow and divide, and for how fast the tumor itself spreads. In NHL, indolent lymphomas are slow growing and referred to as low grade. Aggressive lymphomas are fast growing and referred to as high grade. Aggressive lymphomas are considered more curable than indolent lymphomas. Indolent lymphomas may respond to treatment but tend to recur. (Recurrence is also called relapse.)

Staging refers to where the tumor is contained and where it has spread. The stages of non-Hodgkin’s lymphoma are:

Stage I. In Stage I (early disease), lymphoma is found in only one lymph node area or in only one area or organ outside the lymph nodes.

Stage II. In Stage II (locally advanced disease), lymphoma is found in two or more lymph nodes on the same side of the diaphragm or the lymphoma extends from a single lymph node or single group of lymph nodes into a nearby organ.

Stage III. In Stage III (advanced disease), lymphoma is found in lymph node areas on above and below the diaphragm. Lymphoma may have also spread into areas or organs adjacent to lymph nodes, such as the spleen.

Stage IV. In Stage IV (widespread disease), the lymphoma has spread (metastasized) via the bloodstream to organs outside the lymph system, such as the bone marrow, brain, skin, or liver.

Treatment Options

The main treatments for non-Hodgkin’s lymphoma are:

In early stages of lymphoma, doctors may recommend watchful waiting where treatment is delayed until symptoms appear or worsen. Treatment for lymphomas generally uses chemotherapy (particularly intensive regimens using several drugs) or a combination of chemotherapy and radiation. Monoclonal antibody biologic drugs, (a treatment approach also called immunotherapy), are now being used more frequently in combination with chemotherapy drugs. Transplantation is mainly used to treat patients who relapse. Surgery is not a usual treatment option.

Patients may also wish to consider enrolling in a clinical trial that tests new and experimental drugs or treatments.

Bone marrow - series

 Click the icon to see a series detailing bone marrow transplant. 

Assessing Treatment Success

In assessing the success of a clinical trial, doctors often refer to the tumor response. A complete response, for example, means that there is no longer any evidence at all of the disease by examination, blood tests, or x-ray studies. It does not necessarily mean, however, that the disease is cured. It may still recur later on.

In judging the success of a treatment for NHL, the most important criteria are overall survival and the duration of time until the disease progresses or the patient dies.

Chemotherapy

Chemotherapy plays a role in the treatment of nearly all patients with lymphoma and has achieved remarkable results, even in late stages. It uses drugs to kill cancer cells. Such drugs are called cytotoxic drugs. Chemotherapy is referred to as systemic therapy because the drugs travel throughout the bloodstream to the entire body.

Chemotherapy may also be used along with radiation.

Chemotherapy Administration

A chemotherapy cycle is usually 21 - 28 days. Patients take the drugs for a few days, then have a period of rest. The drugs may be taken as pills at home or given by injection or infusion in a medical center or doctor’s office. Chemotherapy is injected into the spinal fluid if the cancer has spread to the brain. This approach is called intrathecal chemotherapy. Intrathecal chemotherapy is also used as a preventive measure in patients at high risk for central nervous system involvement. Some patients receiving chemotherapy need to remain in the hospital for several days so the effects of the drug can be monitored.

Effective Regimens and Drugs

CHOP. The current standard chemotherapy regimen for NHL is CHOP. CHOP is a combination of cyclophosphamide, doxorubicin hydrochloride (Adriamycin), vincristine (Oncovin), and prednisone. It is proving to be particularly effective for many stages of lymphoma when used in combination with rituximab (Rituxan), a biologic drug. (See Biologic Therapy section of this report.) Some studies of this combination in low-grade lymphomas have reported response rates of 70 - 100%.

CVP. This stands for cyclophosphamide, vincristine, and prednisone. It is another common chemotherapy regimen for non-Hodgkin’s lymphoma. It is also used in combination with rituximab.

Fludarabine. Fludarabine (Fludara) is a type of drug called a nucleoside analogue. It is one of the most used drugs for treating low-grade lymphomas. Fludarabine is often used in a chemotherapy regimen called FND (fludarabine, mitoxantrone, and dexamethasone). Other fludarabine regimens for follicular and low-grade lymphomas are FAD (fludarabine, doxorubicin, and dexamethasone) and FMD (fludarabine, mitoxantrone, and dexamethasone). Fludarabine is also being studied in combination with rituximab.

Etoposide. Etoposide is another cancer drug that is sometimes used in a regimen called EPOCH (etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin.) EPOCH may be used in combination with rituximab.

Side Effects and Complications

Side effects and complications of any chemotherapeutic regimen are common. They are more severe with higher doses. Side effects may increase over the course of treatment. Radiation treatment may worsen chemotherapy side effects.

Common Side Effects. Common side effects include:

These side effects are nearly always temporary. Most patients are able to continue with normal activities for all but perhaps a few days a month.

Serious Side Effects. Serious chemotherapy side effects can also occur and may vary depending on the specific drugs used. They include:

Long-Term Complications.

In general, these serious late side effects are dependent on the cumulative drug dose and rate of administration.

Biologic Therapy (Immunotherapy)

Biological response modifier therapy, also called immunotherapy, uses the body's own immune system to fight cancer. These biologic drugs are often combined with other treatments.

Monoclonal antibodies (MAbs) are the main drugs used in biologic therapy. MAbs are designed in the laboratory to mimic the body’s natural antibodies and attack specific antigens (foreign substances) produced by the cancer. Lymphomas carry antigens that provoke strong immune responses and so are particularly good candidates for MAb therapy.

Rituximab

Rituximab (Rituxan) was the first monoclonal antibody approved for cancer. This drug targets the CD-20 antigen, which is found on most B-cell lymphomas. It is the most commonly used biologic drug, particularly in combination with standard chemotherapy regimens.

Rituximab is used to treat many types of CD20-positive tumors. Rituximab is used as a single drug for low-grade or follicular lymphoma that has either returned after being treated (relapsed) or has not been helped by other treatments (refractory). It is also used in combination with other drugs for other types and stages of lymphomas including diffuse large B-cell (DLBC). Rituximab in combination with CHOP (a regimen called R-CHOP, or CHOP-R) is used for first-line treatment of aggressive lymphomas.

Rituximab is given by infusion. The treatment has mild-to-moderate short-term side effects, including nausea, fever, chills, hives, dizziness, and headache. Uncommon and more serious side effects are severe allergic reactions, very low blood pressure, blood abnormalities, wheezing, infections, and sudden heart events.

Rituximab has also been associated with cases of progressive multifocal leukoencephalopathy (PML), a rare and potentially deadly brain disorder. Patients who experience any of the following symptoms should immediately contact their doctors:

Patients who have previously had hepatitis B, or who are at high-risk for this viral infection, should be tested before taking rituximab because the drug has been linked to reactivation of the hepatitis B virus. Patients who are HIV-positive may experience more adverse effects from rituximab than with CHOP alone.

Radioimmunotherapies

Some newer MAbs are used to treat NHL by attaching radioactive molecules to them. When the drug is injected, the monoclonal antibody targets an antigen (protein) on the surface of the tumor. The radioisotope is then delivered directly into the tumor where it kills the cancer. Ibritumomab and tositumomab both target the CD-20 antigen. Treatment with these drugs takes about 7 - 9 days to complete, compared to several months for traditional chemotherapy treatments.

Overall response rates of over 50% have been reported with these drugs, with up to 30% having no evidence of cancer for a period of time.

In general, these drugs cause fewer side effects than traditional chemotherapy. However, serious complications may include skin infections, severe allergic reactions, and temporary lowering of blood counts. Due to the radioisotope component, these drugs are also more difficult to administer than rituximab. They tend to be used if patients do not respond to rituximab.

Other Biologic Drugs

Proteasome Inhibitors. Bortezomib (Velcade) is approved for treatment of mantle cell lymphoma in patients who have received at least one prior therapy.

Investigational Biologic Therapies

Vaccines. Although still experimental, lymphoma vaccines are used to treat -- not prevent -- cancer. They are part of an immunotherapy approach called personalized medicine; each vaccine is individually tailored to the genetic composition of the patient’s tumor. The vaccine is usually given a few months after a patient receives chemotherapy. The BiovaxID vaccine is in late-stage clinical trials.

Radiation

Radiation uses high-energy x-rays to kill cancer cells and shrink tumors. Radiation is commonly used to treat indolent lymphomas and may also be used palliatively to relieve symptoms. It is very often the sole therapy for early stage (stage I or II) lymphomas. The dose administered ranges from 35 - 50 Gy and depends on a number of factors: The type of lymphoma, the age of the patient, whether the intent is to cure or relieve symptoms, how close sensitive organs are to the diseased area, and whether radiation is being combined with chemotherapy.

Radiation is tailored to the individual and usually limited to the diseased areas and possibly nearby regions:

Side Effects and Complications

Side effects and complications of radiation generally depend on the target site in the body. They include:


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 Click the icon to see an image of hypothyroidism. 

 Click the icon to see an image of the uterus and ovaries. 

Transplantation

Stem cell procedures have proven to produce long-term survival and even cures in some patients with intermediate- and high-grade non-Hodgkin's lymphomas.

Stem cell transplantation involves removing and replacing stem cells, which are produced in the bone marrow. Stem cells are the early forms for all blood cells in the body (including red, white, and immune cells). Cancer treatments harm growing cells as well as cancer cells, and so the healthy stem cells must be replaced by transplanting them from the donor into the patient.

Transplantation is usually reserved for patients with relapsed aggressive lymphoma who are still sensitive to the effects of chemotherapy. Transplantation procedures do not work for patients whose tumors are not responsive to drugs.

Collecting the Stem Cells

Sources of Cells. Stem cells must first be collected in one of the following ways:

Peripheral blood stem cell transplantation is easier to perform and is done more often than bone marrow transplantation. It also seems to be superior in terms of cost, quality of life, and the need for less supportive care.

Donor or Patient Cells. The marrow or blood stem cells can be taken from the patient (autologous) or from a matched donor (allogeneic):

The Blood Stem Cell Collection Procedure. With peripheral blood stem cell transplantation:

Formed elements of blood
Blood transports oxygen and nutrients to body tissues, and returns waste and carbon dioxide. Blood also distributes nearly everything that is carried from one area in the body to another place within the body. For instance, blood helps transport hormones from the endocrine organs to their target organs. Blood also helps maintain body temperature. The protective functions of blood include clot formation and the prevention of infection.

The Transplantation Procedure

Transplantation Side Effects and Complications

Stem-cell transplantation is a serious and complex procedure that can cause many short- and long-term side effects and complications. Early side effects of transplantation are similar to chemotherapy and include nausea, vomiting, fatigue, mouth sores, and loss of appetite. Bleeding due to reduced platelets is a high risk during the first four weeks. Later side effects include fertility problems (if the ovaries are affected), thyroid gland problems (which can affect metabolism), lung damage (which can cause breathing problems) and bone damage. In younger people, there is a small long-term risk for development of secondary cancers such as leukemia.

Two of the most serious complications of transplantation are infection and graft-versus-host disease.

Infection resulting from a weakened immune system is the most common danger. The risk for infection is most critical during the first 6 weeks following the transplant, but it takes 6 - 12 months post-transplant for a patient’s immune system to fully recover.

Many patients develop severe herpes zoster virus infections (shingles) or have a recurrence of herpes simplex virus infections (cold sores and genital herpes). Pneumonia, and infection with germs that normally do not cause serious infections such as cytomegalovirus, aspergillus (a type of fungus), and Pneumocystis jerovicii (a fungus) are among the most important life-threatening infections.

It is very important that patients take precautions to avoid infections. Guidelines for post-transplant infection prevention include:

Graft-versus-host disease (GVHD) is a serious attack by the patient's immune system triggered by the donated new marrow in allogeneic transplants. Mild cases of GVHD can actually be helpful as they can cause graft-versus-lymphoma where the immune system kills remaining lymphoma cells. Still, severe GVHD can pose serious complications.

Acute GVHD occurs in 30 - 50% of allogeneic transplants, usually within 25 days. Its severity ranges from very mild symptoms to a life-threatening condition (more often in older patients). The first sign of acute GVHD is a rash, which typically develops on the palms of hands and soles of feet and can then spread to the rest of the body. Other symptoms may include nausea, vomiting, stomach cramps, diarrhea, loss of appetite and jaundice (yellowing of skin and eyes). To prevent acute GVHD, doctors give patients immune-suppressing drugs such as steroids, methotrexate, cyclosporine, tacrolimus, and monoclonal antibodies.

Chronic GVHD can develop 70 - 400 days after the allogeneic transplant. Initial symptoms include those of acute GVHD. Skin, eyes, and mouth can become dry and irritated, and mouth sores may develop. Chronic GVHD can also sometimes affect the esophagus, gastrointestinal tract and liver. Bacterial infections and chronic low-grade fever are common. Chronic GVHD is treated with similar medicines as acute GVHD.

Too much sun exposure can trigger GVHD. Be sure to always wear sunscreen (SPF 15 or higher) on areas of the skin that are exposed to the sun. Stay in the shade when you go outside.

Resources

References

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Review Date: 2/24/2012
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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