Hodgkin’s lymphoma (also called Hodgkin’s disease) is abnormal or uncontrollable growth of cells in the lymphatic system, which is part of the body’s immune system. It often begins in the cells of the larger and more central lymph nodes of the body, including the lymph nodes of the largest blood vessels of the central chest, neck, abdomen along the spine, and in groin and armpit areas where the vessels return from the legs and arms. As the cancer spreads, it hinders the body’s capacity to fight infections.
Meaning of lymphoma
The lymphatic system refers to a network of minute vessels that run throughout the body. The vessels are located next to the veins and arteries, but are smaller and narrower. Lymphatic vessels transport a clear fluid known as lymph fluid from the extremities and organs of the body back into blood circulation. Along the lymphatic vessels are lymph nodes. The lymphatic system fights infection and diseases and is a core component of the body’s immune system.
Lymphoma is a term used for cancer of the lymphatic system. There are two major types of lymphoma, Hodgkin’s lymphoma (HL, less common) and non-Hodgkin’s lymphoma (NHL, more common). The name Hodgkin’s is derived from that of the British doctor Thomas Hodgkin, who first described the condition in 1832.
How common is Hodgkin’s lymphoma?
Hodgkin’s lymphoma (HL) is a rare form of cancer, making up just 0.5 percent of all cancer cases in the United States. Roughly 1 in 500 people in the U.S. will be diagnosed with HL at some point in their life. Currently, more than 170,000 people are living with Hodgkin’s lymphoma in the U.S., with around 9,000 new cases diagnosed every year. Fortunately, HL is a highly treatable and often curable cancer. More than 75 percent of HL patients live longer than 10 years after being diagnosed with the disease.
Types of Hodgkin’s lymphoma
The exact cause of Hodgkin’s lymphoma is not known. However, it is recognized that changes (mutation) in the DNA of infection-fighting cells known as B-cells result in the accumulation of a large number of abnormal and oversized B-cells in the lymphatic system. Once these abnormal cells crowd out normal cells, symptoms of Hodgkin’s lymphoma occur. There are different types of Hodgkin’s lymphoma depending on the cells involved and their behavior.
- Classical Hodgkin’s lymphoma
This is the most common type of Hodgkin’s lymphoma. It is characterized by presence of large abnormal cells known as Reed-Sternberg in the lymph nodes. It is further divided into subtypes which include:
- Nodular sclerosis Hodgkin’s lymphoma
- Mixed cellularity Hodgkin’s lymphoma
- Lymphocyte-rich classical Hodgkin’s lymphoma
- Lymphocyte-depleted Hodgkin’s lymphoma
- Lymphocyte-predominant Hodgkin’s lymphoma
This is a very rare type of Hodgkin’s lymphoma. It is characterized by presence of large, abnormal cells known as popcorn cells in the lymph nodes. People with this type of HL have a higher chance of being cured when the cancer is detected in early stage.
Risk factors for Hodgkin’s lymphoma
- Age: HL is commonly diagnosed in people 15-30 years old, though those older than 55 years also may have it.
- Family history of lymphoma: If you have a close family member who has suffered from either Hodgkin’s lymphoma or Non-Hodgkin’s lymphoma, then you are at increased risk.
- Sex: Males are at higher risk than females.
- History of Epstein-Barr virus (EBV) infection: Illnesses caused by EBV, such as infectious mononucleosis, increase the risk of HL.
- Compromised immune system: If your immunity has been weakened by HIV/AIDS or drugs given after organ transplant, you have higher risk of having Hodgkin’s lymphoma.
Symptoms of Hodgkin’s lymphoma
- Painless swelling of the lymph nodes of the groin, armpits or neck.
- Fever and chills.
- Persistent fatigue.
- Night sweats.
- Lymph node pain after drinking alcohol or increased sensitivity to effects of alcohol.
- Loss of appetite.
- Unexplained weight loss (as much as 10 percent or more of your body weight).
See your doctor immediately if you have these symptoms.
Diagnosis of Hodgkin’s lymphoma
- Physical exam: The doctor will examine your body for swollen lymph nodes in the neck, groin and underarm, together with swollen liver or spleen.
- Blood tests: The doctor will order a sample of your blood to be examined in the laboratory for cancerous cells.
- Imaging: Hodgkin’s lymphoma is diagnosed using X-ray, CT (computerized tomography) scan and PET (positron emission tomography).
- Bone marrow biopsy: The doctor may recommend checking your bone marrow for cancer. A sample of your bone marrow will be collected using a needle and examined under a microscope for cancer cells.
- Surgery for swollen lymph nodes: A minor surgery to remove part or all of the enlarged lymph node for testing may be recommended. The lymph node is sent to the laboratory where it is examined for large, abnormal cells.
Staging of Hodgkin’s lymphoma
Once Hodgkin’s lymphoma is diagnosed, the doctor will assign it a stage to help with choosing the right treatment. Stage is a term used to describe how far the cancer has spread. HL stages are:
- Stage I: Cancer still limited to a small area in the organ of origin or to just one lymph node.
- Stage II: Cancer has invaded an organ and nearby lymph nodes or has spread in two or more lymph nodes. However, it is still limited to the section of the body where it originated, either below or above the diaphragm.
- Stage III: Cancer has invaded the lymph nodes on both sections of the body, both above and below the diaphragm. It also may be found in one portion of the organ or tissue near lymph node groups or inside the spleen.
- Stage IV: Cancer has spread beyond the lymph nodes into organs such as lungs, bones and liver. Several organs and tissues have been invaded. This is advanced stage Hodgkin’s lymphoma, with the tumor found in distant lymph nodes.
Apart from these stages, the doctor may use letters A and B to highlight the kinds of symptoms you are experiencing.
- A: Used to indicate that you are having no symptoms due to the cancer.
- B: Used to indicate that you are experiencing serious symptoms due to the cancer, including persistent fever, severe night sweats or unintended weight loss.
Treatment of Hodgkin’s lymphoma
In cancer care, various specialists usually work together to develop an overall treatment plan that combines different kinds of treatments. This multidisciplinary approach brings together a medical oncologist, radiation oncologist, oncology nurses, physician assistants, nurse practitioners, pharmacists, social workers, dietitians, counselors and other professionals. The treatment options and care recommendations by this team will depend on your type of lymphoma, stage of lymphoma, results of PET-CT scans, possible side effects, your preferences, and your overall health. The objective of treatment is to destroy cancer cells and control the disease.
Chemotherapy is the use of chemicals (drugs) that travel through the bloodstream to kill lymphoma cells. The drugs can be taken as pills, administered through a vein, or both methods can be used. Many combinations of chemotherapy drugs can be used to treat Hodgkin’s lymphoma, with the drugs reaching nearly all areas of the body through blood. In people with early-stage classical Hodgkin’s lymphoma, chemotherapy is combined with radiotherapy for better efficacy, with radiotherapy done after chemotherapy. But for people with advanced-stage Hodgkin’s lymphoma, chemotherapy can be used alone or in combination with radiotherapy.
2. Radiation therapy
Radiotherapy is the use of high-energy beams of X-rays or other particles to kill cancer cells. The treatment is directed by a radiation oncologist, a doctor specialized in radiation therapy for cancer treatment. To treat Hodgkin’s lymphoma, radiation is always delivered through external beam radiotherapy, which is radiation given from a machine located outside the body. The radiation therapy schedule (regimen) consists of a specific number of treatments delivered over a certain period of time. For classical Hodgkin’s lymphoma, radiotherapy may be used alone or in combination with chemotherapy. But for people having early-stage lymphocyte-predominant Hodgkin’s lymphoma, only radiation is used.
During radiotherapy, the patient lies on a table and then a large machine is moved around, directing energy beams to specific areas of the body. When radiation is delivered only to the areas of the body known to have the tumor, this is called involved field radiation. It is usually combined with chemotherapy. Delivery of radiation to areas above the diaphragm such as chest, neck and underarms is called mantle field radiation; while delivery of radiation to areas below the diaphragm, such as abdomen, pelvis and spleen is called inverted-Y field radiation. When radiation is delivered to all the lymph nodes in the body with the aim of destroying cancer cells that might spread to other lymph nodes, this is called total nodal irradiation. But when radiation is delivered to the entire body usually before chemotherapy and/or stem cell (or bone marrow) transplant, this is called total body irradiation.
Various techniques may be used to direct radiation more precisely to the affected lymph nodes. In turn, this ensures reduced risk of damage to healthy tissues. Commonly used radiotherapy techniques include:
(a) Intensity-modulated radiotherapy (IMRT), which varies the direction and strength of radiation beams in order to minimize effects on healthy tissues.
(b) Involved-site radiotherapy, where radiation is only focused on the lymph nodes having the cancer.
(c) Proton therapy, where protons are used instead of X-rays to treat cancer.
Radiation therapy for Hodgkin’s lymphoma can cause immediate side effects such as skin redness, stomach upset, fatigue, sore throat, loose bowel movements and hair loss at the treated site. Most of these side effects will disappear when treatment is completed. With advancements in radiotherapy, the risk of long-term (late) side effects such as thyroid problems, heart disease, stroke, vascular damage and infertility, is reduced significantly.
3. Stem cell transplant
A stem cell transplant is the replacement of a diseased bone marrow with healthy stem cells in order to grow new bone marrow. Stem cell transplant is usually considered for recurrent Hodgkin’s lymphoma after chemotherapy and radiotherapy have failed to offer lasting treatment. During a stem cell transplant, the doctor will remove your blood stem cells, freeze them and then store them for later use. You then will be given high-dose chemotherapy and radiotherapy to destroy cancerous cells in your body. Your stem cells will be thawed and injected back into your body through the vein. A healthy bone marrow will develop from the stem cells.
Also called biologic therapy, immunotherapy is tailored to boost the natural defenses of the body and empower them to fight the cancer. Immunotherapy uses materials made either in the laboratory or by the body to target, improve or restore the function of your immune system. For instance, monoclonal antibodies can be used to target certain molecules of the body, attaching themselves to those molecules and causing them to die or to be more vulnerable to chemotherapy and radiotherapy. For example, radiolabeled antibodies have radioactive particles and will attach directly to diseased cells, ensuring that these cells are damaged easily with small amounts of radiation and with minimal injury to nearby healthy tissues.