Lymphomas

Non-Hodgkin Lymphoma

Non-Hodgkin lymphoma (NHL) is the most common cancer of the lymphatic system, a part of the immune system. Since the early 1970s, incidence rates for NHL have nearly doubled. Of the nearly 500,000 Americans who are lymphoma survivors, approximately 332,000 have this form. More than 65,000 cases of NHL are diagnosed annually in the United States.

NHL is not a single disease but rather a group of several closely related cancers. The World Health Organization estimates that there are at least 61 types of NHL. Although the various types of NHL have some things in common, they differ in their appearance under the microscope, their molecular features, their growth patterns, their impact on the body and how they are treated.

NHLs are broadly divided into two major groups: B-cell lymphomas and T-cell lymphomas. B-cell lymphomas develop from abnormal B-lymphocytes and account for 85 percent of all NHLs. T-cell lymphomas develop from abnormal T-lymphocytes and account for the remaining 15 percent of all NHLs. NHLs may also be classified as indolent (slow-growing) or aggressive (fast-growing).

Symptoms

Common signs and symptoms of NHL include swelling of the lymph nodes (which is often but not always painless), fever, night sweats, unexplained weight loss and lack of energy. While most people who have these complaints will not have NHL, anyone with persistent symptoms should be seen by a physician to make sure that lymphoma is not present.

Risk Factors

The causes of NHL remain unknown; however, a risk for develop¬ing lymphoma may be higher in individuals who:

have a family history of NHL (though no hereditary pattern has been well established)
are affected with an autoimmune disease
have received an organ transplant
have been exposed to chemicals such as pesticides, fertilizers or organic solvents for a long period
have been infected with viruses, such as Epstein-Barr, human T-lymphotropic virus type 1 (HTLV-1), HIV/AIDS, hepatitis C or certain bacteria, such as H-pylori

Common Types of NHL

Because there are so many different types of NHL, and new subtypes are continually being identified, classifying lymphoma is complicated and has evolved over the years. The most common types of NHL include:

Diffuse large B-cell lymphoma: 31 percent
Follicular lymphoma: 22 percent
Mantle cell lymphoma: 6 percent
Chronic lymphocytic leukemia/small lymphocytic lymphoma: 6 percent
Mucosa-associated lymphoid tissue: 5 percent
Peripheral T-cell lymphoma: 6 percent
Anaplastic large cell lymphoma (subtype of PTCL): 2 percent
Lymphoblastic lymphoma, either T-cell or B-cell: 2 percent
Burkitt-like lymphoma: 2 percent
Lymphoplasmacytic lymphoma: 1 percent

Treatment Options

Many useful treatment options exist for NHL patients, including:

watchful waiting
chemotherapy
radiation therapy
stem cell transplantation
novel targeted agents
newer versions of established agents.

The form of treatment chosen depends on the type of lymphoma and the stage (see Table 1) of disease as well as other factors, including age, prior therapies received and the patient’s overall health.

Some patients may relapse (disease returns after treatment) or become refractory (disease does not respond to treatment). However, numerous treatment options exist for patients with relapsed or refractory NHL, which are often referred to as secondary therapies. Many of the novel therapeutic agents that have been approved by the United States Food and Drug Administration, as well as those being investigated in clinical trials, focus specifically on those with relapsed or refractory disease.

Before starting treatment, patients should discuss all available treatment options with their physician.

Table 1. Stages of Non-Hodgkin Lymphoma

NHL is divided into four stages based on how far the disease has spread.

Stage I (early disease)	the cancer is found only in a single lymph node OR in one organ or area outside the lymph node.
Stage II (locally advanced disease)	the cancer is found in two or more lymph node regions on one side of the diaphragm.
Stage III (advanced disease)	the cancer involves lymph nodes both above and below the diaphragm.
Stage IV (widespread disease)	the cancer is found in several parts of one or more organs or tissues (in addition to the lymph nodes). Or, it is in the liver, blood or bone marrow.

Participating in Clinical Trials

Clinical trials are crucial for identifying effective drugs for lymphoma patients. Patients interested in participating in a clinical trial should talk to their physician. Contact the Lymphoma Research Foundation’s Helpline for an individualized clinical trial search by calling (800) 500-9976 or emailing helpline@lymphoma.org.