Hodgkin lymphoma is the name for a group of cancers that start in the lymph nodes and then spread to surrounding areas of the body. Lymph nodes are small organs found at various sites in the body, such as under the armpits, in the groin, back of the abdomen, and in the neck.
These nodes help fight infection by filtering out bacteria and other harmful substances. Many people notice slightly swollen nodes in the neck when they have a cold or the flu; however, these swellings are usually temporary and disappear within a week or two.
Hodgkin lymphoma is a type of lymphoma, a form of cancer that affects the lymphatic system. Lymphomas are the third most common type of cancer in children. Hodgkin lymphoma usually occurs in 2 age groups: people between the ages of 15 and 40, and people over the age of 55.
The exact cause of Hodgkin lymphoma is unknown, as is true for most types of cancer. Studies have found an increased risk of Hodgkin lymphoma in people who have had the Epstein-Barr virus. This has led researchers to think that viral factors may play a role in causing this type of cancer. However, this is still not proven.
Other risk factors may include an HIV infection, a family history of Hodgkin lymphoma, and previous chemotherapy or radiation exposure. People who have suppressed immune systems due to certain medications or medical conditions may also be at risk.
Symptoms and Complications
People with Hodgkin lymphoma may experience any of the following signs and symptoms:
- a painless swelling of the lymph nodes in the armpits, neck, or groin area
- persistent fatigue
- fever and chills
- night sweats
- weight loss (unintended)
- loss of appetite
- severe itching (rarely)
- enlarged spleen
- difficulty breathing
- swelling of the legs
If you discover a painless mass, particularly in the neck region, and it doesn't disappear after a few weeks, you should see a doctor to have it checked out. Often, especially in children, painless enlargements in the lymph nodes are the only symptoms of Hodgkin lymphoma.
Making the Diagnosis
To diagnose Hodgkin lymphoma, a doctor will need to perform a thorough physical exam, checking the lymph nodes carefully for signs of swelling. In some cases, an abnormal mass can be detected just by feeling the nodes. Some nodes are deep in the body, so they can't be easily felt.
Occasionally, the spleen enlarges (under the left rib cage) and can be felt by the doctor. A lymph node biopsy (the removal of some lymph node tissue for analysis in the laboratory) is necessary to determine the cause of enlarged lymph nodes and to confirm the diagnosis of cancer.
Other possible tests that may be needed include blood and urine tests, as well as special scans like a computed tomography (CT) scan or positron emission tomography (PET) scan. These scans help doctors find out if the cancer has spread to other areas of the body.
A bone marrow biopsy may also be done. Bone marrow is the spongy material in the centre of most bones. This test is done to see if the lymphoma has spread to the bone marrow.
All these tests are useful for the purpose of "staging the cancer." This means determining the extent of the cancer to see if it's in an early or advanced stage. Staging is important for planning the course of treatment.
There are four stages of Hodgkin lymphoma. Stage 1 is the mildest and stage 4 is the most severe.
- stage 1: the cancer is still localized in one lymph node region, which means that it has not spread
- stage 2: the cancer has spread to a small extent to nearby lymph areas, on the same side of the diaphragm (the muscle that separates the areas of the chest from the abdomen)
- stage 3: the cancer has spread to lymph node regions both below and above the diaphragm
- stage 4: the cancer has spread to organs outside of the lymph system – common areas of spread are the liver and bone marrow
Treatment and Prevention
The goal of treatment is to bring about complete remission, which is the total absence of any signs or symptoms of the disease. The type of treatment depends on the stage of the cancer.
The main treatments for Hodgkin lymphoma are chemotherapy and radiation therapy. Chemotherapy regimens require that a person take a combination of different anticancer medications commonly used to treat Hodgkin lymphoma. Chemotherapy treatment may last 3 to 6 months, with cycles of medication followed by periods of no medication for the body to recover. Radiation therapy uses high-energy beams of invisible particles to penetrate the body and destroy cancer cells. Radiation therapy takes place over several weeks. Depending on the stage of disease, treatment consists of chemotherapy alone or a combination of chemotherapy and radiation therapy.
If a relapse occurs after chemotherapy treatment, then it will be treated again. The treatment method will depend on where the cancer is and what treatment options were used when the cancer was last treated. Higher doses of anticancer medication may be used, and this treatment may be combined with radiation.
In cases where the cancer returns, an autologous bone marrow transplant (in which a person's own bone marrow is removed before chemotherapy and then replaced afterwards) is often done so that the body can handle larger doses of anticancer medications. Because it is autologous, that is, one's own bone marrow is replaced, there is no risk of rejection or need to take transplant medications as one might for allogeneic transplants (i.e., from another donor).
When Hodgkin lymphoma is discovered at an early stage, the cure rate is very high – up to 90% of cases.