Lymphoma is a group of cancers that affect the cells that play a role in the immune system, and primarily represents cells involved in the lymphatic system of the body. The lymphatic system is a network of branching tubes that carry a fluid called lymph along with cells that play a major role in fighting disease and infection. The lymphatic system also contains small nodes that filter the lymph, which may contain bacteria or viruses.
Cancer occurs when normal disease fighting cells called lymphocytes undergo a transformation in which they grow and multiply uncontrollably. As the abnormal cells multiply, they may collect in one or more lymph nodes or in other lymph tissues. They may form a mass, or tumor, or invade neighboring tissues or distant organs.
Lymphomas fall into two major categories: Hodgkin lymphoma or HL, also called Hodgkin’s disease, and all other lymphomas, also called non-Hodgkin lymphomas. These cancers may have similar symptoms but can be distinguished by examining blood or tissue samples under a microscope. Hodgkin’s disease arises from abnormal B lymphocytes, cells that produce proteins that attach to abnormal or infected cells, alerting the immune system to destroy them. Non-Hodgkin lymphoma arises from either abnormal B cells or T cells, which kill infected cells and regulate immunity. It has specific genetic markers. There are many different subtypes of lymphomas that respond differently to therapies.
Hodgkin’s disease is most common in young adults ages 16 to 34 and in older people ages 55 and older. Non-Hodgkin lymphoma is more likely to occur in older people.
The National Cancer Institute estimates that 65,980 new cases of non-Hodgkin's lymphoma will be diagnosed in 2009. This represents 89 percent of all lymphomas, and 4 percent of all cancers diagnosed. Approximately 8,000 cases of Hodgkin lymphoma are detected per year, representing less than 1 percent of all cancers.
Non-Hodgkin lymphomas characteristically are associated with abnormalities of chromosomes. The way in which these abnormalities lead to lymphomas is a major focus of investigation at the Kimmel Cancer Center.
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Researchers do not know the exact causes of lymphoma. Most people are diagnosed over the age of 60. People with weakened immune systems from infections such as HIV/AIDS, Epstein-Barr virus, Hepatitis C, and Helicobacter pylori may be more susceptible to lymphomas. Survivors of nuclear reactor accidents and others exposed to high levels of radiation are at an increased risk for developing non-Hodgkin lymphoma. People who had previous radiation therapy are also at a higher risk for lymphoma.
The early symptoms of lymphoma may be minor or mimic common illness. The first sign of lymphoma may be a painless swelling in the neck, under an arm or in the groin. An enlarged lymph node may cause other symptoms by pressing against a vein (swelling of an arm or leg), a nerve (pain, numbness or tingling), or the stomach (early feeling of fullness). Other symptoms include fevers, chills, unexplained weight loss, night sweats, lack of energy, chest pain, lower back pain or itching or rashes.
Lymphoma patients referred to the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins are seen by a team of doctors who specialize in the disease. Hematologists, oncologists and pathologists examine the lymph nodes to define the specific type of lymphoma to best plan treatment. A dedicated hematologic pathology division within our medical center has extensive expertise in the development and uses state-of-the-art technologies to accurately diagnose leukemia and lymphoma.
Lymphomas are diagnosed by taking a small sample of an enlarged lymph node and examining it under a microscope -- a procedure called a biopsy. Examining lymph nodes for lymphoma is best done by experienced hematopathologists -- pathologists who focus primarily on this type of disease using specialized techniques. The type of lymphoma can be identified by the physical appearance of the cancer cells under the microscope, or by using markers that identify special molecules on the lymphoma cells
Additional tests, such as blood tests, a chest X-ray or examination of bone marrow cells or tissue can help doctors see how far the disease has spread and what organs are affected.
Staging is a process used to determine how far the cancer has spread. It’s important for doctors to know the stage of disease so they can plan the best treatment. Most types of lymphoma are given stages of I, II, III, or IV based on the size of the tumor and how far from the original site in the body the cancer has spread:
- Stage I means cancer is limited to only one group of lymph nodes, or more rarely in a single organ that does not belong to the lymph system.
- Stage II means cancer is found in two or more groups of lymph nodes on the same side as the diaphragm, a thin muscle below the lungs that helps in breathing. In addition, an organ not in the lymph system but close to the involved nodes may be affected.
- Stage III means cancer is present in lymph node groups on both sides of the diaphragm, occasionally with the involvement of other adjacent organs. It may also involve the spleen, an organ located in the abdomen behind the ribs that removes and destroys old red blood cells and helps fight infection.
- Stage IV means cancer has spread to the bone marrow or the lungs, or other organs far away from the affected lymph nodes.
Your doctor may also use some letters in describing lymphoma. Patients complaining of so-called ‘B’ symptoms like fever, weight loss or night sweats may have a letter B added to their stage. Those without the symptoms might have an A added to their stage. If any organ that does not belong to the lymph system is involved, the cancer stage is denoted with a letter E after the stage, for extralymphatic organ involvement. If the spleen is involved, the corresponding letter is S.
Non-Hodgkin lymphoma is usually categorized into one of three grades:
- Low-grade or indolent: slow-growing lymphomas that can go for many years without treatment.
- Intermediate-grade or aggressive: faster-growing lymphomas.
- High-grade or highly aggressive: very fast-growing lymphomas.
After reviewing your lab results and accurately diagnosing your stage of lymphoma, a multidisciplinary team of doctors at Johns Hopkins Kimmel Cancer Center will design a treatment plan tailored for each patient, based on their age, symptoms and type of lymphoma.
There are four main types of treatment for lymphomas, which may be used alone or in combination to fight a particular type of lymphoma: chemotherapy, radiation therapy, biological therapy and bone marrow transplant or stem cell transplant.
Hodgkin lymphoma is usually treated with chemotherapy (drug treatment to destroy cancer cells) and radiation therapy. The treatment of non-Hodgkin lymphoma depends on the particular type of cancer. Chemotherapy is usually the main treatment, with radiation therapy or antibody or biological therapy added as necessary.
A combination of three or more drugs are generally used. All or most of the drugs are administered either as quick injections or as slow infusions into your veins, though some may be taken as pills. There are a number of effective drug combinations available. Chemotherapy is typically administered every two to three weeks for a number of cycles. Side effects can depend on which drugs were given and how much, but include fatigue, hair loss, poor appetite, nausea or vomiting, diarrhea, or infertility.
Some patients with non-Hodgkin lymphoma may also receive drugs called biological therapy – treatments that improve the body’s defenses against the disease. For example, the drug rituximab, given by infusion, attaches itself to a molecule on the surface of cancerous B cells, inactivating the cancer cells. Side effects include fever, chills, itching or lightheadedness.
Radiation therapy uses high-energy rays to kill lymphoma cells by damaging the genetic material they contain. Some patients receive targeted radiation from a large machine aimed at the neck, armpits or other parts of the body affected by lymphoma. This type of therapy takes place five days a week for several weeks. Others may receive radiation directed to larger areas of the body.
The side effects of radiation therapy, including fatigue, can depend on the dose of radiation and the part of the body that is treated. Skin in the area being treated may become red, dry, and tender. Hair loss in the treated area also may occur.
Bone Marrow Transplant or Stem Cell Transplant
A bone marrow transplant or stem cell transplant gives a patient healthy stem cells – immature cells that grow into different parts of the blood – taken from the marrow, the soft, fatty tissue inside the bones, replacing bone marrow that is either not working properly or has been destroyed by chemotherapy or radiation. Stem cells may be taken from the patient before getting chemotherapy or radiation. They also may come from a relative or other donor, or from umbilical cord blood.
Most patients get high doses of chemotherapy, radiation, or both, before the bone marrow transplant to kill any cancer cells that might remain and make room for new stem cells to grow. Doctors then deliver the stem cells through a tube injected into the bloodstream. They find their way into the bone marrow and begin reproducing to make healthy new blood cells. While receiving stem cells, patients may experience pain, chills, fever, hives, chest pain or other symptoms.
Researchers at Johns Hopkins Kimmel Cancer Center and other medical centers across the country are researching and testing novel vaccines to help fight lymphomas.
Lymphoma survivors may have lingering side effects such as bone or joint pain, numbness and tingling of the hands and feet (peripheral neuropathy), difficulty concentrating, fatigue, hot flashes, or night sweats. Remember that your body needs time to recover; effects like fatigue may last for a year or more. Premenopausal women may experience menopausal symptoms. Always discuss any health concerns and symptoms with your doctor.
As you recover, take charge of your health by eating healthy, exercising and reducing stress. Avoid tobacco and limit alcohol intake. Keep up with screenings for other cancers, like mammographies and colonoscopies.
Patients with non-Hodgkin and Hodgkin lymphomas are managed by the faculty of the Division of Hematologic Malignancies at the Sidney Kimmel Kimmel Comprehensive Cancer Center at The Johns Hopkins Hospital. More information on our Blood and Bone Marrow Cancers Program. The Lymphoma Research Foundation and The Leukemia and Lymphoma Society provide information and resources for patients and survivors.