Lymphoma refers to a group of blood cancers that develop in the lymphatic system. The lymphatic system is part of the body’s immune system that fights infections and drains excess fluid from body tissues. The two types of lymphoma are Hodgkin lymphoma which is also called Hodgkin’s disease; and all other lymphomas which are also called non-Hodgkin lymphomas.
Hodgkin lymphoma is one of the most curable forms of cancer. It was named for the doctor who first described the disease.
There are many types of non-Hodgkin lymphoma. Aggressive or high-grade lymphomas grow and spread quickly. Non-aggressive or low-grade lymphomas grow slowly and cause few or no symptoms.
Lymphoma can start almost anywhere in the body. It may start in the lymph nodes or an organ such as the spleen. It can spread to any part of the body. Treatment can cure some people and may allow others to live for years. How well treatment works depends mostly on the type of lymphoma and when it’s diagnosed.
Most lymphoma is non-Hodgkin lymphoma. In adults, non-Hodgkin lymphoma affects males more than females. It often occurs between the ages of 60 and 70.
Non-Hodgkin lymphoma has become more common in the past few decades. This may be related to the rise in the number of people who have a suppressed immune system, such as people infected with human immunodeficiency virus (HIV) and those who have had an organ transplant and need to take drugs that alter the immune system.
Age is a major determinant of the type of non-Hodgkin lymphoma. Slow growing lymphomas (low grade) are more likely to occur in an older person. Fast growing (high grade aggressive) non-Hodgkin lymphomas usually affect children and young adults. Lymphomas are classified by the specific characteristics of the cancer cells and the parts of the body affected.
The main symptom of both Hodgkin and non-Hodgkin lymphomas, is swollen lymph nodes in the neck, under the arms, or in the groin. Other symptoms can include fever, night sweats, extreme fatigue and unexplained weight loss.
Because swollen lymph nodes caused by lymphoma usually do not result in pain, they may get larger over a long time before they are noticed. Also, fever may come and go for several weeks. Even the unexplained weight loss may continue for months before an individual consults a doctor.
Diagnosis usually begins with a physical exam with the doctor checking for swollen lymph nodes and organs throughout the body to look for general signs of the disease. If lymphoma is suspected, a doctor may ask for blood tests to check the numbers and appearance of the blood cells. Sometimes the diagnosis can be made with a special blood test called flow cytometry. This test is a way to sort and identify the different types of cells in the blood, including cancerous lymph cells.
A doctor may also recommend a lymph node biopsy to confirm the diagnosis. In this test, all or part of a lymph node is removed using a needle or during minor surgery. A specialist then views the tissue to check for lymphoma.
Other tests such as CT scans or an MRI of the chest and abdomen and/or a positron emission tomography (PET) scan may also be required in some instances. Often a bone marrow biopsy is performed.
These additional tests are usually done to determine the stage of lymphoma. The stages range from Stage I (cancer limited to one area, such as one lymph node) to Stage IV (cancer is growing in many lymph nodes throughout the body or in the bone marrow or other organs).
Occasionally, laparoscopic surgery may be done to help to determine the cancer’s stage.
Hodgkin lymphoma can often be cured. The duration of non-Hodgkin lymphoma varies and some forms are slow-growing. In these instances, treatment may be postponed until symptoms appear. In general, both Hodgkin and non-Hodgkin lymphoma will continue to worsen unless they are treated.
There is no definitive way to prevent lymphoma. But individuals may be able to lower the risk by taking precautions to avoid becoming infected with HIV.
Radiation is the usual treatment for Hodgkin disease that is localised to one group of lymph nodes. For more advanced stages of Hodgkin disease, combination chemotherapy with several different drugs may be used.
Treatment for non-Hodgkin lymphoma depends on the grade of lymphoma (low, or high), the stage of the disease, and the age and health of the patient. Low-grade (slow-growing) lymphomas, the ones that occur more often in older people, may not require immediate treatment if there are no symptoms. Early, aggressive therapy does not improve survival for most low-grade lymphomas.
In low-grade lymphoma that is advancing or causing symptoms may be treated in a variety of ways. The choice of therapy depends on the age of the person and whether there are other significant medical problems. Low dose chemotherapy won’t cure the lymphoma but may help to keep decrease the number of cancer cells. More aggressive therapy would include high dose chemotherapy, sometimes with immunotherapy using a biologic agent. Also doctors might consider a bone marrow transplant.
In a bone marrow transplant, the patient’s bone marrow cells are killed and then cancer-free bone marrow cells are injected. Stem cells are immature cells that grow into blood cells. In a stem cell transplant, the patient’s stem cells are removed and treated to kill the cancer before being injected back into the patient.
Immunotherapy draws from the body’s immune system to kill cancer cells or limit their growth. Monoclonal antibodies are the most commonly used biologic therapy to treat lymphoma, and these are specific proteins that attack certain cells.
Monoclonal antibodies are injected into the bloodstream and they may be used alone or to transport drugs, toxins, or radioactive material to cancer cells.