Lymphomas

Hodgkin Lymphoma

Hodgkin lymphoma, also known as Hodgkin disease, is not as common as non-Hodgkin lymphoma. According to the American Cancer Society, approximately 8,500 new cases of Hodgkin lymphoma are projected to occur each year. Although the cancer can occur in both children and adults, it is most commonly diagnosed in adolescents and young adults between the ages of 15 and 35 and in older adults over age 50.

Hodgkin lymphoma is characterized by the presence of Reed-Sternberg (R-S) cells, although other abnormal cell types may be present. Hodgkin lymphoma usually starts in the lymph nodes. However, it often spreads from one lymph node to another and can also spread to other organs.

Symptoms

Common signs and symptoms 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 Hodgkin lymphoma, anyone with persistent symptoms should be seen by a physician to make sure that lymphoma is not present.

Risk Factors

The cause of Hodgkin lymphoma remains unknown, however, risk for developing Hodgkin lymphoma may be higher in individuals who:

have a family history of Hodgkin lymphoma (though no hereditary pattern has been well established)
are infected with the Epstein-Barr virus (which causes mononucleosis)
are infected with HIV
have a weakened immune system caused by either an inherited condition or the use of immunosuppressants to prevent organ transplant rejection.

Common Types of Hodgkin Lymphoma

Hodgkin lymphoma has been divided into two main classifications, classical Hodgkin lymphoma (accounts for approximately 95 percent of all cases of Hodgkin lymphoma) and lymphocyte predominant Hodgkin lymphoma. The type of Hodgkin lymphoma a patient has may affect treatment choices.

Classical Hodgkin Lymphoma

Nodular sclerosis is the most common subtype of Hodgkin lymphoma, accounting for between 60 percent and 80 percent of all cases of Hodgkin lymphoma. In patients with nodular sclerosis, the involved lymph nodes contain areas composed of R-S cells mixed with normal white blood cells. The lymph nodes often contain prominent scar tissue, hence the name nodular sclerosis (scarring). The disease is more common in women than men, and it usually affects adolescents and adults under 50. The great majority of patients are cured with current treatments.

Mixed cellularity accounts for about 15 percent to 30 percent of all cases of Hodgkin lymphoma and is found more commonly in men than women. The disease is characterized by the involved lymph nodes containing many R-S cells in addition to several other cell types. This subtype primarily affects older adults and may be associated with HIV and the Epstein-Barr virus. More extensive disease is usually present by the time this subtype is diagnosed.

Lymphocyte depletion accounts for fewer than 5 percent of all Hodgkin cases. It is characterized by few normal lymphocytes but abundant R-S cells. Lymphocyte depletion is aggressive and usually not diagnosed until the disease is widespread.

Lymphocyte-rich accounts for less than 5 percent of all Hodgkin cases. The disease may be diffuse (spread out) or nodular (knot-like) in form and is characterized by the presence of numerous normal lymphocytes and very few abnormal cells and classical R-S cells. This subtype of Hodgkin lymphoma is usually diagnosed at an early stage in adults and has a low relapse rate.

Nodular Lymphocyte Predominant Hodgkin Lymphoma

Nodular lymphocyte predominant accounts for 5 percent to 10 percent of all Hodgkin cases. It primarily affects more men than women and is usually diagnosed in people under 35. In nodular lymphocyte predominant lymphoma, most of the lymphocytes found in the lymph nodes are normal (not cancerous).

Typical R-S cells are usually not found in this subtype, but large, abnormal B-cells, sometimes referred to as popcorn cells, can be seen, as well as reactive small B-cells, which may be distributed in a nodular (knot-like) pattern within the tissues. This subtype is usually diagnosed at an early stage and is not very aggressive. In many ways, this form of Hodgkin lymphoma resembles low-grade (indolent) B-cell non-Hodgkin lymphoma.

Treatment Options

Hodgkin lymphoma has been studied more than any other type of lymphoma. These studies have led to rapid advances in the diagnosis and treatment of the disease, resulting in well over 80 percent of Hodgkin lymphoma patients being cured.

Most patients treated for Hodgkin lymphoma will receive some form of chemotherapy and sometimes radiation therapy as their frontline treatment. Stem cell transplantation is typically used in the relapsed or refractory (resistant to treatment) setting. Surgery may also be an option under special circumstances, but it is used primarily to obtain a biopsy for diagnostic purposes. Most recently, in August 2011, the Food and Drug Administration approved brentuximab vedotin (Adcetris) for the treatment of relapsed/refractory Hodkin lymphoma.

Many promising therapies are currently under investigation in clinical trials for Hodgkin lymphoma, including:

Histone deacetylase inhibitors (e.g., panobinostat or vorinostat, also known as Zolinza)
Proteasome inhibitors (e.g., bortezomib, also known as Velcade)
Alkylating agents (e.g., bendamustine, also known as Treanda)

Although the cure rate in Hodgkin lymphoma is already high, research continues to look for ways to treat the small minority of patients who are resistant to treatment or those that relapse.