Hodgkin's Disease
Hodgkin's disease is a type of lymphoma distinguished by the presence of a particular kind of cancer cell called a Reed-Sternberg cell.
In the United States, about 8,000 new cases of Hodgkin's disease occur every year. The disease is more common in males than in females--about three men are affected for every two women. Hodgkin's disease rarely occurs before age 10. It is most common in people between the ages of 15 and 34 and in those older than 60.
The cause of Hodgkin's disease is unknown. There is strong evidence that, in some people, Epstein-Barr virus infection causes B lymphocytes to become cancerous and transform into Reed-Sternberg cells. Although there are some families in which more than one person has Hodgkin's disease, the disease does not appear to be contagious.
Symptoms
A person with Hodgkin's disease usually becomes aware of one or more enlarged lymph nodes, most often in the neck but sometimes in the armpit or groin. Although usually painless, sometimes the enlarged lymph nodes may be painful for a few hours after a person drinks large amounts of alcohol.
People with Hodgkin's disease sometimes experience fever, night sweats, and weight loss. They can also have itching and fatigue. Some people have Pel-Ebstein fever, an unusual pattern of high temperature for several days alternating with normal or below-normal temperature for days or weeks. Other symptoms may develop, depending on where the cancerous cells are growing. For example, enlargement of lymph nodes in the chest may partially narrow and irritate airways, resulting in a cough, chest discomfort, or shortness of breath. Enlargement of the spleen or lymph nodes in the abdomen may cause discomfort in the abdomen.
 See the table Symptoms of Hodgkin's Disease.
Diagnosis
A doctor suspects Hodgkin's disease when a person with no apparent infection develops persistent and painless enlargement of lymph nodes that lasts for several weeks. The suspicion is stronger when lymph node enlargement is accompanied by fever, night sweats, and weight loss. Rapid and painful enlargement of lymph nodes--which may occur when a person has a cold or infection--is not typical of Hodgkin's disease. Sometimes enlarged lymph nodes deep within the chest or abdomen are found unexpectedly on a chest x-ray or computed tomography (CT) scan performed for another reason.
Abnormalities in blood cell counts and other blood tests may provide supportive evidence. However, to make the diagnosis, a doctor must perform a biopsy of an affected lymph node to see if it is abnormal and if Reed-Sternberg cells are present. Reed-Sternberg cells are large cancerous cells that have more than one nucleus. Their distinctive appearance can be seen when a biopsy specimen of lymph node tissue is examined under a microscope.
The type of biopsy depends on which node is enlarged and how much tissue is needed. A doctor must remove enough tissue to be able to distinguish Hodgkin's disease from other diseases that can cause lymph node enlargement, including non-Hodgkin's lymphoma, infections, or other cancers.
The best way to obtain enough tissue is with an excisional biopsy. A small incision is made to remove a piece of the lymph node. Occasionally, when an enlarged lymph node is close to the body's surface, a sufficient amount of tissue can be obtained by inserting a hollow needle through the skin and into the lymph node (needle biopsy). When an enlarged lymph node is deep inside the abdomen or chest, surgery may be needed to obtain a piece of tissue.
Staging
Before treatment is started, doctors must determine how extensively the lymphoma has spread--the stage of the disease. The choice of treatment and the prognosis are based on the stage. An initial examination may detect only a single enlarged lymph node, but procedures to find if and where the lymphoma has spread (staging) may detect considerably more disease.
The disease is classified into four stages based on the extent of its spread (I, II, III, IV; the higher the number, the more the lymphoma has spread). The four stages are subdivided, based on the absence (A) or presence (B) of one or more of the following symptoms: unexplained fever (more than 100° F for 3 consecutive days), night sweats, and unexplained loss of more than 10% of body weight in the preceding 6 months. For example, a person with a stage II lymphoma who has experienced night sweats is said to have stage IIB Hodgkin's disease.
Several procedures are used to stage or assess Hodgkin's disease. Basic blood tests, including tests of liver and kidney function, along with computed tomography (CT) scans of the chest, abdomen, and pelvis are standard. CT scans are quite accurate in detecting enlarged lymph nodes or spread of the lymphoma to the liver and other organs.
Positron emission tomography (PET) scanning is the most sensitive technique for determining the stage of Hodgkin's disease and for evaluating the person's response to treatment. Because living tissue can be identified on a PET scan, doctors can use this imaging technique to distinguish scar tissue from active Hodgkin's disease after the person has undergone treatment. Gallium scanning is another procedure that is used for staging and for following the effects of treatment. A small dose of radioactive gallium is injected into the bloodstream, and 3 to 4 days later, the person is scanned with a device that detects the radioactivity and then produces an image of the internal organs.
Uncommonly, a person with Hodgkin's disease needs surgery to determine whether the disease has spread to the abdomen. During this surgery, the spleen is often removed and a liver biopsy is performed to determine whether the disease has spread to these organs. Abdominal surgery is performed only when its results are likely to affect the choice of treatment--for example, when a doctor needs to know whether to use radiation therapy alone.
See the table Stages of Hodgkin's Disease.
Treatment and Prognosis
With radiation therapy, chemotherapy, or both, most people who have Hodgkin's disease can be cured.
Radiation therapy alone cures about 80% of people who have stage IA or IIA disease. Treatments are usually given on an outpatient basis over about 4 or 5 weeks. Radiation is beamed at the affected areas and at the surrounding lymph nodes. Alternatively, chemotherapy is used, followed by radiation therapy for those with stage IB or IIB disease or for those whose chest lymph nodes are greatly enlarged. With this dual approach, about 85% of people are cured.
In stage III and IV disease, a combination of chemotherapy drugs is used. The most common combination for Hodgkin's disease is ABVD (doxorubicin [Adriamycin], bleomycin, vinblastine, and dacarbazine). Each cycle of chemotherapy lasts for 1 month, with a total treatment time of 6 or more months. Other combinations of chemotherapy drugs are sometimes used, but whether these are better than ABVD remains unknown.
It is uncertain whether people with stage III disease receive added benefit when radiation therapy is given along with chemotherapy. For people with very large lymph nodes in the chest, adding radiation therapy to chemotherapy is often recommended. The cure rate of people with stage III disease ranges from 70 to 80%. Cure rates for people with stage IV disease, while not as high, are above 50%.
Although chemotherapy greatly improves the chances for a cure, side effects can be serious. The drugs may cause temporary or permanent sterility, an increased risk of infection, potential damage to other organs, such as the heart or lungs, and reversible hair loss. Sometimes leukemia can develop 5 to 10 years after chemotherapy for Hodgkin's disease. There is also an increased risk of non-Hodgkin's lymphoma or other cancers such as lung, breast, or stomach cancers 10 or more years after treatment with chemotherapy drugs; the risk may increase further when a person is also treated with radiation therapy.
A person who has a remission (with the disease under control) after initial treatment, but then relapses (lymphoma cells reappear), has less of a chance for long-term survival. The cure rate for people who relapse ranges from 10 to 50%. Among those who relapse in the first 12 months after initial treatment, cure rates are somewhat lower, whereas the rates for those who relapse later tend to be somewhat higher. People who relapse after initial treatment generally are treated with additional chemotherapy at usual doses followed by high doses. This is likely to be followed by autologous stem cell transplantation, which involves using the person's own stem cells (see Section 16, Chapter 187). People who relapse more than a year after initial treatment do not always require stem cell transplantation. High-dose chemotherapy with stem cell transplantation is generally a safe procedure, with less than a 5% risk of death related to the treatment.
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