Hodgkin's disease — also known as Hodgkin's lymphoma — is an uncommon cancer of the lymphatic system, which is part of your immune system. It's named after the British physician Thomas Hodgkin, who first described the disease in 1832 and noted several characteristics that distinguish it from other lymphomas.

In Hodgkin's disease, cells in the lymphatic system grow abnormally and may spread beyond the lymphatic system. As Hodgkin's disease progresses, it compromises your body's ability to fight infection.

Hodgkin's disease most commonly affects people between the ages of 15 and 40 and people older than age 55. It's one of two common types of cancers of the lymphatic system. Non-Hodgkin's lymphoma, the other type, is far more common. In the United States in 2004, there were about 7,880 new cases of Hodgkin's disease, compared with 54,320 new cases of non-Hodgkin's lymphoma.

Each year, about 1,300 Americans die of Hodgkin's disease. However, death rates for this disease have dropped by 60 percent since the 1970s. Advances in diagnosis, staging and treatment of Hodgkin's disease have helped to make this once uniformly fatal disease highly treatable with the potential for full recovery.

Many initial signs and symptoms may be similar to those of the flu, such as fever, fatigue and night sweats. Eventually, tumors develop.

Signs and symptoms of Hodgkin's disease may include:

• Painless swelling of lymph nodes in your neck, armpits or groin
• Persistent fatigue
• Fever and chills
• Night sweats
• Unexplained weight loss
• Loss of appetite
• Itching

The exact cause of Hodgkin's lymphoma is unknown. Hodgkin's disease is among a group of cancers called lymphomas — cancers of the lymphatic system. The lymphatic system includes the lymph nodes (lymph glands), which are located throughout your body and are connected by small vessels called lymphatics. The spleen, thymus gland and bone marrow also are part of the lymphatic system.

Hodgkin's disease commonly begins in the lymph nodes. Some lymph nodes are in areas more readily noticed, such as in your neck, above your collarbone, under your arms or in your groin area. Enlarged lymph nodes in the chest cavity also are common. Lymphomas may spread outside the lymph nodes to virtually any part of your body.

Abnormal B cells
A key step in Hodgkin's disease involves the development of abnormal B cells, a type of lymph cell that is an important part of your immune system's response to foreign invaders. B cells normally work with T cells, which derive from the thymus, to fight infection. T cells kill foreign invaders directly. B cells become plasma cells, which in turn produce antibodies that neutralize foreign invaders (proteins).

When B cells develop into large abnormal cells, these abnormal, cancerous cells are called Reed-Sternberg cells after the two pathologists who first discovered them. Instead of undergoing the normal cell cycle of life and death, these Reed-Sternberg cells don't die, and they continue to produce abnormal B cells in a malignant process.

The following are risk factors for Hodgkin's disease:

• Age. People between the ages of 15 and 40, as well as those older than 55, are most at risk of Hodgkin's disease.
• Family history. Anyone with a brother or a sister who has the disease faces an increased risk of developing Hodgkin's, though this may be due to similar environmental exposures rather than genetic factors.
• Sex. Males are slightly more likely to develop Hodgkin's.
• Past Epstein-Barr infection. People who have had illnesses caused by the Epstein-Barr virus, such as infectious mononucleosis, may be four times as likely to develop Hodgkin's disease as people who haven't had a past Epstein-Barr infection.
• Compromised immune system. Having a compromised immune system, such as from HIV/AIDS or from having an organ transplant requiring medications to suppress your immune response, also appears to put you at a greater risk of Hodgkin's lymphoma.

Many people with Hodgkin's disease experience no classic symptoms. Sometimes, an abnormality found on a chest X-ray done for nonspecific symptoms leads to an eventual diagnosis of Hodgkin's disease.

Because the symptoms of Hodgkin's are similar to those of other disorders, such as influenza, the disease can be difficult to diagnose. Some distinctive characteristics help diagnose Hodgkin's disease, and these include:

• Orderly spread. The pattern of spread is orderly, progressing from one group of lymph nodes to the next.
• Only rare "skipping." The disease rarely skips over an area of lymph nodes as it spreads.

A tissue sample (biopsy) of an enlarged lymph node is needed to make the diagnosis. The pathologist looks for changes in the normal lymph node architecture and cell characteristics, including the presence of Reed-Sternberg cells. The affected lymph nodes may contain only a few of these malignant cells.

Other procedures that may be valuable in evaluating Hodgkin's disease include X-ray, computerized tomography (CT) scan, magnetic resonance imaging (MRI), positron emission tomography (PET) scan, bone marrow biopsy and blood tests. If the disease is predominantly in your abdomen, you may need exploratory surgery to help define the extent of the disease.

Staging Hodgkin's disease
Once the diagnosis is confirmed, doctors "stage" the disease. Staging is how doctors judge the extent of the disease, which will likely affect your treatment options.

• Stage I. The cancer is limited to one lymph node region.
• Stage II. In this stage, the cancer is in two different lymph nodes, but is limited to a section of the body either above or below the diaphragm.
• Stage III. When the cancer moves to lymph nodes both above and below the diaphragm, but hasn't spread to other organs, it's considered stage III.
• Stage IV. This is the most advanced stage of Hodgkin's disease. Stage IV Hodgkin's disease affects not only the lymph nodes but also other parts of your body, such as the bone marrow or your liver.

The most important factor in the treatment of Hodgkin's disease is the stage of the disease. The number and regions of lymph nodes affected and whether only one or both sides of your diaphragm are involved are also important considerations. Other factors affecting decisions about treating this disease include:

• Your age
• Your symptoms
• Whether you're pregnant
• Your overall health status

The goal of treatment is to destroy as many malignant cells as possible and bring the disease into remission. More than 80 percent of people with stage I or stage II Hodgkin's disease survive for 10 years or more with proper treatment. The five-year survival rate for those with widespread Hodgkin's disease is about 60 percent.

Treatment options include:

Radiation
When the disease is confined to a limited area, radiation therapy is the treatment of choice. It's typical to radiate the affected nodes and the next area of nodes where the disease might progress. The length of radiation treatment varies depending on the stage of the disease. Radiation therapy may be used alone, but is commonly used in conjunction with chemotherapy. If you relapse after radiation therapy, chemotherapy becomes necessary.

Some forms of radiation therapy may increase the risk of other forms of cancer, such as breast or lung cancer. The risk of breast cancer from standard dose radiation is even higher for girls and women treated when they were younger than 30 than for other people and is generally too high for this therapy to be considered. Most children with Hodgkin's disease are treated with combination chemotherapy, but may also receive low-dose radiation therapy.

Chemotherapy
When the disease progresses and involves more lymph nodes or other organs, chemotherapy is the preferred treatment. Chemotherapy uses specific drugs in combination to kill tumor cells.

A major concern with chemotherapy is the possibility of long-term side effects and complications, such as heart damage, lung damage, liver damage and secondary cancers, such as leukemia. Although these severe effects occur in only a small number of people, great effort is being put into finding equally effective regimens with less toxicity. Drug regimens have been developed that substantially diminish the likelihood of long-range, life-threatening complications, including acute leukemia in people who have received multiple courses of chemotherapy and radiation therapy.

These regimens are commonly referred to by their initials, such as:

• ABVD, which consists of Adriamycin (doxorubicin), bleomycin, vinblastine and dacarbazine
• BEACOPP, which consists of bleomycin, etoposide, Adriamycin, cyclophosphamide, Oncovin (vincristine), procarbazine and prednisone
• COPP/ABVD, which consists of cyclophosphamide, Oncovin, procarbazine, prednisone, Adriamycin, bleomycin, vinblastine and dacarbazine
• Stanford V, which consists of Adriamycin, vinblastine, mechlorethamine, etoposide, vincristine, bleomycin and prednisone
• MOPP, which consists of mechlorethamine, Oncovin, procarbazine and prednisone

MOPP had been the basic regimen, but it's very toxic. ABVD is a newer regimen, with less severe side effects, and is currently the preferred treatment.

Bone marrow transplant
If the disease recurs after an initial chemotherapy-induced remission, high-dose chemotherapy and transplantation of your own (autologous) bone marrow or peripheral stem cells may lead to prolonged remission. Peripheral stem cells are bone marrow cells mobilized from the bone marrow into the bloodstream. Because high doses of chemotherapy destroy bone marrow, your own marrow or peripheral blood stem cells are collected before treatment and frozen. You'll undergo chemotherapy, and then your own cells, which have been protected from the effects of the treatment, are injected back into your body.

A diagnosis of cancer can be extremely challenging. Remember that no matter what your concerns or prognosis, you're not alone. The following strategies and resources may make dealing with cancer easier:

• Know what to expect. Find out everything you can about your cancer — the type, the stage, your treatment options and their side effects. The more you know, the more active you can be in your own care. In addition to talking with your doctor, look for information in your local library and on the Internet. The National Cancer Institute answers questions from the public and can be reached at (800) 422-6237. Or you can contact the American Cancer Society at (800) 227-2345.
• Be proactive. Although you may feel tired and discouraged, don't let others — including your family or your doctor — make important decisions for you. It's vital that you take an active role in your treatment.
• Maintain a strong support system. Having a support system and a positive attitude can help you cope with any issues, pain and anxieties that might occur. Although friends and family can be your best allies, they sometimes may have trouble dealing with your illness. If so, the concern and understanding of a formal support group or others coping with cancer can be especially helpful. Although support groups aren't for everyone, they can be a good source for practical information. You may also find you develop deep and lasting bonds with people who are going through the same things you are.
• Set reasonable goals. Having goals helps you feel in control and can give you a sense of purpose. But don't choose goals you can't possibly reach. You may not be able work a 40-hour week, for example, but you may be able to work at least part time. In fact, many people find that continuing to work can be helpful.
• Take time for yourself. Eating well, relaxing and getting enough rest can help combat the stress and fatigue of cancer. Also, plan for the downtimes when you may need to rest more or limit what you do.
• Stay active. Receiving a diagnosis of cancer doesn't mean you have to stop doing the things you enjoy or normally do. For the most part, if you feel well enough to do something, go ahead and do it. It's important to stay involved as much as you can.