Hodgkin disease is a cancer of the lymphoid system. The lymphoid system is made up of various tissues and organs, including the lymph nodes, tonsils, bone marrow, spleen, and thymus. These organs produce, store and carry white blood cells to fight infection and disease.
Hodgkin disease accounts for 5% of cancers diagnosed in children less than 15 years of age in the United States. It has been reported in infants and very young children, but is considered rare before the age of five years. The number of cases increases significantly in the second decade of life, making it most common in teenagers, comprising 16% of cancers in adolescents.
Hodgkin disease occurs more frequently in boys than in girls, except in the age group between 15 and 19 years of age when it occurs more frequently in girls.
What causes Hodgkin disease?
The causes of Hodgkin disease are unknown Studies that examine the rates of disease within populations, called epidemiologic studies, suggest some possible factors that may be at work. However, there is no evidence that any one particular factor is responsible for this disease.
There may be a relationship between viral infection and Hodgkin disease, although a virus alone does not cause the disease. The Epstein Barr virus (EBV), the virus responsible for mononucleosis, is seen in the tumor tissue of 20%-30% of patients, but it is not known to be the cause of the disease. Most people are exposed to EBV by the time they are adults and most do not get Hodgkin disease, so the role of EBV still needs to be studied.
Studies have reported an increased risk of disease in close relatives of patients with Hodgkin disease, especially same-sex siblings. Although the risk is two- to five-fold higher for siblings, the likelihood that a sibling will get Hodgkin disease remains extremely low. The clustering of cases of Hodgkin’s disease within families and in certain ethnic groups may suggest a genetic predisposition to the disease.
Hodgkin disease is more common in people whose immune system is weakened. Immune deficiency can be caused by genetic conditions or can be acquired. It may also occur in individuals infected with human immunodeficiency virus (HIV, the cause of AIDS).
What are the symptoms of Hodgkin disease?
Most patients who have Hodgkin disease experience swollen lymph nodes, called lymphadenopathy. These nodes are usually larger than those that occur with common infections, and do not respond to standard treatments like antibiotics. The affected lymph nodes are usually found in the neck or above the collar bone, and less commonly under the arms or in the groin. The lymph nodes are most often painless, firm, rubbery, and movable in the surrounding tissue.
Poor appetite, weight loss, night sweats, fever, a sense of ill-feeling and fatigue can also be experienced by children with Hodgkin disease. They are "systemic" symptoms with a more generalized affect on the entire body.
Itching (pruritus) is another symptom in patients with Hodgkin disease. This can be mild or severe, and tends to occur more often in patients with advanced disease. Pruritus is less commonly found in children.
How is the extent of the disease determined?
If cancer cells are found in the biopsy of lymph nodes or other parts of the body, more tests will need to be performed to see if the cancer cells have spread to other parts of the body. This process is called staging. Staging will identify the extent of the cancer and is an important factor in determining the appropriate treatment for the child
A standardized staging system developed for Hodgkin disease is called the Ann Arbor staging system. It includes stages I-IV, defined by the anatomical locations of lymph nodes which are infiltrated by tumor. The higher the stage number, the more the disease has spread throughout the lymphoid system and other parts of the body.
Learn more about the Ann Arbor staging system.
Each stage is then further classified as either A or B.
A refers to "asymptomatic" disease.
B symptoms include fever exceeding 100.4˚F / 38.0˚C, drenching night sweats, and weight loss of at least 10% of body weight over 6 months.
At the time of diagnosis, approximately
- 60% of children with Hodgkin Disease have stage I or II disease
- 30% have stage III disease
- 10% have stage IV disease
What are the factors affecting the type of treatment and chance of cure?
The type of treatment and likelihood of long term cure depend on many factors.
The presence of the following factors can decrease the chance of long-term cure;
- Having an advanced stage of disease (stage III or stage IV).
The presence of B symptoms at the time of diagnosis. About one-third of the children staged for Hodgkin disease have the B classification. This percentage increases in advanced disease.
Tumor "bulk" is also considered an adverse prognostic factor. This means a larger lymph node or group of nodes.
Histology – the way the tumor looks under the microscope
These children may need more intense therapy as well as radiation therapy to have the best chance of cure.
High survival rates have been reported in children with Hodgkin disease using different treatment strategies. Almost all children with stage I or II disease can be cured, although about one in 10 children with early stage disease may develop new disease and need additional therapy. With the recurrence of the disease the chance of long term survival is decreased.
About 8 in 10 children with stage III and IV disease can be cured.
Cindy Schwartz, MD, Rhode Island Hospital
June 2008