Non-Hodgkin lymphoma is a cancer of the lymphatic system and usually starts in lymphocytes (white blood cells) found in one or more lymph nodes. White blood cells are a part of the lymphatic system that helps fight diseases and infections. There are many types of non-Hodgkin lymphoma. The type is determined by how the cancerous cell looks under a microscope.
Non-Hodgkin lymphoma can occur at any age, but the incidence increases with age, especially after the age of 60. Non-Hodgkin lymphoma makes up approximately 4% of new cancer cases each year, and there is a 1 in 42 lifetime chance for Canadian men, and a 1 in 54 lifetime chance for Canadian women, of having this type of cancer.
The exact cause isn't known, but doctors believe a virus or activation of abnormal genes may be involved in some cases. Some risk factors are thought to be:
- being aged 60 and above
- autoimmune disease (e.g., rheumatoid arthritis)
- exposure to pesticides, chemical solvents, and dyes
- exposure to some viral infections such as Epstein-Barr virus
- immunodeficiency states such as AIDS, congenital immunodeficiency, or chronic immunosuppression by medications
- prior exposure to chemotherapy or radiation therapy
People can have non-Hodgkin lymphoma even without these risk factors.
Symptoms and Complications
Swollen glands in the neck, armpit, or groin are the first symptoms of non-Hodgkin lymphoma. Other possible symptoms include unexplained fever, night sweats, weight loss, and stomach or intestinal pain. The type of symptoms experienced depends on where the lymphoma is located. A lymphoma in the chest can lead to a swollen face, breathing difficulties, or fluid buildup in the lungs (pleural effusion). If a lymphoma starts in the abdomen or small intestine, symptoms may include a loss of appetite, diarrhea, constipation, weight loss, or a bloated and painful abdomen. A lymphoma in the groin can lead to swollen legs. Lymphomas can also cause thickened, dark, and itchy areas on the skin.
Making the Diagnosis
Your doctor will ask you questions about your symptoms and perform a physical exam. If your doctor suspects non-Hodgkin lymphoma, other tests will be performed to confirm the diagnosis.
Blood tests will check for abnormalities in blood cells and organ (e.g., liver, kidney) function. X-rays, ultrasounds, or computed tomography (CT) and positron emission tomography (PET) scans will check lymph nodes deep inside the body that cannot be examined by your doctor.
A lymph node biopsy (removing a small tissue sample of the lymph gland for microscope examination) will confirm the diagnosis. A doctor may take a biopsy of the bone marrow to see if cancer has spread. This test involves inserting a needle into your lower back to draw out some material inside your bone and looking at the sample through a microscope to see if there are any cancer cells.
With the information obtained from tests, non-Hodgkin lymphoma will be given a stage and grade. Knowing the stage and grade of the cancer, you and your doctor will be able to decide what treatment will be best for you.
The following stages are used for non-Hodgkin lymphoma:
- stage I: Cancer is found in only one lymph node area.
- stage II: Cancer is found in two or more lymph node areas on the same side of the diaphragm (the thin muscle under the lungs that helps breathing and separates the chest from the abdomen).
- stage III: Cancer is found in lymph node areas on both sides of the diaphragm.
- stage IV: Cancer has spread to one or more organs (e.g., liver, lungs, brain, bone marrow).
- recurrent: Means that the cancer has come back after it has been treated.
Non-Hodgkin lymphoma is generally divided into 3 groups: indolent (low grade), intermediate grade and aggressive grade lymphomas. Indolent lymphomas are slow growing and may have fewer symptoms. Aggressive-grade lymphomas grow rapidly and behave like acute leukemias. Intermediate-grade lymphomas have clinical qualities between low-grade and aggressive lymphomas.
Treatment and Prevention
Treatment depends on the grade and stage of the cancer. If you have an indolent type of non-Hodgkin lymphoma, your doctor may offer you the option of watchful waiting. During this time, your doctor will monitor you closely and begin treatment only when your condition starts to get worse.
Non-Hodgkin lymphoma is usually treated with:
- biological therapy (helps the body's immune system kill cancer cells)
- chemotherapy (medications that kill cancer cells)
- radiation therapy (high-dose X-rays to kill cancer cells)
- stem cell transplantation (healthy blood cells can be more quickly replaced)
Treatment may involve either one type of treatment, or a combination of treatment options. The treatment plan will depend on the type of lymphoma, the stage of the cancer, and other factors. Because many of the treatments for non-Hodgkin lymphoma can affect fertility, you doctor may discuss options such as banking sperm or harvesting eggs for future pregnancy.
Early stages of the disease may be treated by radiation therapy aimed at the cancerous tumour. The radiation usually prolongs the person's life, although it may not cure the disease.
More advanced or aggressive non-Hodgkin lymphoma is usually treated with chemotherapy, using anticancer medications given one at a time or in combination. If the cancer doesn't go away, or if it returns, the chemotherapy may be increased or repeated.
Chemotherapy in addition to radiation may be effective in treating large, bulky lymphomas or in controlling symptoms such as pain or bleeding from tumours.
In some cases, doctors may perform a bone marrow or stem cell transplant after giving very high doses of chemotherapy. Chemotherapy destroys the cancerous white blood cells as well as the normal and healthy white blood cells, red blood cells, and platelets. In this procedure, a doctor removes bone marrow from a compatible donor and puts it into the recipient after high doses of chemotherapy are given. Sometimes the bone marrow replacement is from the patient (rather than from a donor) themselves, if bone marrow was stored at an earlier time in the treatment process.