Hodgkin lymphoma

Hodgkin lymphoma is a cancer of the immune system. It is also called Hodgkin disease. Hodgkin lymphoma is one of the most curable forms of cancer. It begins in the part of the immune system called the lymph system. The lymph system is made up of an intricate network of immune cells, small blood-vessel-like structures called lymphatics, and lymph nodes. It also includes organs made primarily of immune cells such as the spleen and thymus gland. The lymph (or lymphatic) system helps fights infections and other diseases.

The lymph system includes:

• Lymph: A clear fluid that carries white blood cells (especially lymphocytes) through the lymph system. White blood cells help fight infection.
• Lymph vessels (lymphatics): A network of thin tubes. They carry lymph from different parts of the body to the bloodstream.
• Lymph nodes: Small masses of tissue that store white blood cells. They also remove bacteria and other substances from the lymph. Lymph nodes reside throughout the body, including the neck, underarms, chest, abdomen, pelvis, and groin.
• Spleen: An organ near the stomach that
  • makes lymphocytes
  • filters the blood
  • stores blood cells
  • destroys old blood cells
• Thymus gland: a gland located in the central portion of the chest near the heart. The gland helps create lymphocytes that are important in immune function, especially in children and young adults.

The lymph system also consists of the thymus, tonsils, and bone marrow. Lymph tissue is found in the small intestine as well.

Hodgkin lymphoma usually begins in the lymph nodes. It can spread to almost any tissue or organ. The disease starts when a change occurs to the genetic material of a lymphocyte. This turns the lymphocyte into a large, abnormal cell. Hodgkin lymphoma is distinguished by these unique cancer cells, called Reed-Sternberg cells. The abnormal cells begin dividing out of control. They often go on to form tumor masses in lymph nodes and elsewhere.

Most patients with Hodgkin lymphoma can be cured or have their disease controlled for many years.

Symptoms of Hodgkin lymphoma

The most common early symptom of Hodgkin lymphoma is a swollen lymph node. It is often felt as a painless lump in the neck, armpit, or groin.

Other symptoms include:

• persistent fever
• feeling very tired and weak
• diminished appetite and weight loss
• night sweats
• itchy skin
• cough or trouble breathing
• pain in the lymph nodes after drinking alcohol

Hodgkin's disease is different from another common form of lymphoma, called non-Hodgkin lymphoma. The two diseases share some similarities, but there are many differences in the response to treatments. This makes the distinction between the two diseases very important.

Diagnosing Hodgkin lymphoma

The first step in diagnosis is usually a physical examination and medical history. Your doctor will check for swollen lymph nodes and organs, as well as general signs of disease. He or she will ask about your health habits and past illnesses and treatments.

If your doctor suspects Hodgkin lymphoma, the following tests and procedures may be performed:

• Blood tests. Blood will be drawn from your arm. Various tests will analyze the number and appearance of blood cells under a microscope.
• Lymph node biopsy. Your doctor will remove all or part of a lymph node using a needle or during minor surgery. A specialist will view the tissue under a microscope.
• Bone marrow aspiration and biopsy. A sample of the bone marrow can be removed and examined under the microscope for the presence of abnormal lymphoma cells.
• Immunophenotyping. Identifies Hodgkin lymphoma based on of the characteristics of a patient's cells. This process uses chemical reactions to help identify the nature and characteristics of the abnormal cells. It represents a way in which specific molecules on the surface of the cells can be identified.

There are two main types of Hodgkin lymphoma: classical and nodular lymphocyte predominant. The differences are based upon the appearance of the cells under the microscope. "Classical" Hodgkin disease is more common. The types also differ in the way they look, grow, and spread. There are also other forms of Hodgkin's disease that are less common.

Staging

If you have Hodgkin lymphoma, your doctor will recommend other tests to see if the disease has spread. This process is called staging.

Staging tests may include:

• Lymph node biopsy. This test looks for abnormal cells lymph node tissue.
• Imaging tests, such as
  • Chest x-ray: High-energy radiation takes pictures inside the body.
  • Computed tomography (CT) scan: An x-ray camera rotates around the body making detailed cross-sectional images of tissues and organs.
  • Magnetic resonance imaging (MRI): Radio waves and strong magnets produce detailed images of areas inside the body.
  • Positron emission tomography (PET): Radioactive glucose is injected into the patient's vein. A scanner rotates around the body to locate cells using the glucose. (Cancer cells use more glucose than normal cells, and the radioactive glucose shows up as bright spots on the scans.)
• Bone marrow biopsy. Your doctor may want a sample of your bone marrow. For the procedure, the doctor inserts a needle into the back of the hipbone. The sample usually consists of a small piece of marrow and the marrow liquid inside the bone. The sample is viewed under a microscope.

The four stages of Hodgkin lymphoma are based on

• the number of affected lymph nodes
• whether the lymph nodes are located on one or both sides of the diaphragm (the diaphragm is the thin muscle separating the chest and abdomen)
• where the disease has spread
• whether there is spread to organs that are not part of the lymph and immune system.

Stage I: Lymphoma cells are found in only one lymph node group or lymphoid organ, or in some tissue or organ outside the lymph system.

Stage II: Cancer is found in two or more lymph node groups on the same side of the diaphragm (above or below). Or, it may be in lymph nodes and some tissue or an organ outside the lymph system. All cancer is on one side of the diaphragm.

Stage III: Lymphoma cells are found in lymph node groups both above and below the diaphragm. They may also be found in an area or organ outside the lymph system and/or the spleen.

Stage IV: The cancer is found throughout one or more non-lymphatic organs (such as the lungs, liver, or bone marrow). It may also be in nearby or distant lymph nodes.

Recurrent or relapsed: Hodgkin lymphoma that has come back after treatment.

Resistant: Hodgkin lymphoma that does not go away or continues growing during initial treatment.

There are also letter stages assigned to Hodgkin lymphoma:

A: The patient does not have fever, weight loss, or drenching night sweats.

B: The patient has fever, weight loss, or drenching night sweats.

E: The cancer is found in an organ or tissue that is outside the lymph system but next to an involved lymph node.

S: Hodgkin lymphoma is found in the spleen.

Expected duration of Hodgkin lymphoma

Hodgkin lymphoma can often be cured. Even when there is widespread disease, Hodgkin's is still curable.

Preventing Hodgkin lymphoma

Scientists don't know exactly what causes Hodgkin lymphoma. Possible risk factors for the disease include:

• being infected with certain viruses, such as the Epstein-Barr virus (which causes infectious mononucleosis)
• being infected with human immunodeficiency virus (HIV)
• having a weakened immune system
• having a sibling with Hodgkin lymphoma
• being in young adulthood or older than 55
• being male

Most people with risk factors don't get Hodgkin lymphoma. And most often, people who get the disease don't have clear risk factors.

Treating Hodgkin lymphoma

Patients with Hodgkin lymphoma should receive care from doctors with experience treating this illness. A medical oncologist (cancer doctor) or hematologist will likely oversee the team. The team should also include a radiation oncologist, endocrinologist, neurologist, and others.

The treatment approach will vary, depending on

• type and stage of Hodgkin lymphoma
• tumor size
• patient's age and general health
• symptoms when diagnosed
• whether the cancer has returned
• whether the cancer is getting worse.

Most people with Hodgkin lymphoma receive chemotherapy, radiation therapy, or both. Surgery may be part of the diagnosis and staging process, but is not usually part of the treatment. For patients whose disease has come back, a stem cell transplant may be recommended.

Chemotherapy

Chemotherapy uses drugs to stop the growth of cancer cells. Most chemotherapy for Hodgkin lymphoma is given through a vein. Some drugs are taken by mouth.

Combination chemotherapy is given in cycles. This means you have a treatment followed by a period of rest.

Chemotherapy drugs can damage some normal cells. This may cause short-term side effects. Side effects can include hair loss, nausea, mouth sores, fatigue, and a greater chance of infection. The increased risk of infection occurs because treatment can damage normal bone marrow cells, which also are involved in fighting infections. If platelets (a special type of blood cell) are decreased, patients are more likely to bleed or bruise easily. There are often ways to relieve these symptoms. In male patients, treatment can affect the ability to have children in the future. This is something they should discuss with their doctors. Men should talk with their doctors about banking sperm before starting chemotherapy or radiation.

Immunotherapy

Monoclonal antibodies made in a laboratory can be designed to fight cancer cells. They are usually given along with chemotherapy.

Brentuximab vedotin (Adcetris) targets a protein on the Hodgkin lymphoma cells. This monoclonal antibody is attached to a chemotherapy drug. It facilitates the entry of the chemotherapy into cancer cells to kill them. Brentuximab is given by IV infusion. Potential side effects include low blood cell counts, increased risk of infections, fever, and feeling unwell.

Rituximab may be used in combination with chemotherapy or alone. This monoclonal antibody targets a different protein on the Hodgkin lymphoma cells. It's also given by IV infusion. Side effects are similar to the ones caused by brentuximab.

Immune checkpoint inhibitors are monoclonal antibodies that take advantage of the immune system's ability to attack and destroy cancer cells. Many cancer cells produce "checkpoint" proteins that block the immune system from acting against cancer. Nivolumab (Opdivo) and pembrolizumab (Keytruda) are two examples of checkpoint inhibitors used to treat Hodgkin lymphoma and other cancers. They are given by IV infusion and also have a long list of potential side effects.

Radiation therapy

Radiation therapy uses high-energy radiation to kill cancer cells or stop them from growing. It can shrink tumors and help control pain.

For patients with Hodgkin lymphoma, radiation is usually delivered from a machine outside the body. This is called external beam radiation. It targets the cancerous areas.

Radiation therapy can cause short-term side effects including tender skin, fatigue, and other problems specific to the area being treated. For example, radiation to the abdomen may cause nausea and diarrhea. If radiation is given to areas in the chest, the thyroid gland may be affected, so these patients should have regular tests of their thyroid function.

Stem cell transplant

A stem cell transplant replaces a person's blood-forming cells. Stem cell transplants can use stem cells from your own body or from a donor. Donor stem cell transplant may be necessary if the patient's own stem cells are abnormal or have been destroyed by cancer treatment.

Stem cells (immature blood cells) are removed from the blood or bone marrow of a patient or donor. Once removed, they are examined under a microscope and the cell number is counted. The stem cells are stored for future use.

The patient then undergoes treatment with high-dose radiation or chemotherapy. This treatment also kills important cells in the bone marrow. After treatment, the stored stem cells are put back into the patient's bloodstream. Because these are stem cells, they are able to regenerate and grow into the many different cells normally found in the bone marrow.

During treatment, the patient cannot make any blood cells until the stem cells have had time to mature. This puts the patient at high risk of infection and bleeding. In addition to the short-term risks, there are also long-term side effects. Stem cell transplants should be undertaken only in specialized centers.

Survivors of Hodgkin lymphoma should continue to have regular checkups to monitor their health. Follow-up can also help detect long-term problems related to cancer treatment. Chemotherapy and radiation therapy can lead to an increased risk of heart disease and other cancers, infertility, fatigue, and other long-term effects, as well as thyroid gland problems.

Cancer specialists are studying newer, shorter courses of radiation and fewer cycles of chemotherapy, to see if they can be just as effective as standard therapy. The advantage would possibly mean fewer long-term side effects.

When to call a professional

Contact a doctor if you (or your child) have any of the following symptoms that last more than two weeks:

• enlarged lymph node in the neck, armpit, or groin
• persistent fever
• shortness of breath or asthma-like symptoms and wheezing
• weight loss when not trying to lose weight
• feeling very tired and weak
• night sweats
• itchy skin
• cough or trouble breathing
• pain in the lymph nodes after drinking alcohol.

Prognosis

Hodgkin lymphoma is one of the most curable forms of cancer. A patient's individual outlook depends on many factors, including:

• symptoms when diagnosed
• type and stage of Hodgkin lymphoma
• blood test results
• patient's age, gender, and general health
• whether the cancer is newly diagnosed, responds to initial treatment, or has come back.

Additional info

National Cancer Institute (NCI)
https://www.cancer.gov/

American Cancer Society (ACS)
https://www.cancer.org/

Leukemia & Lymphoma Society
https://www.lls.org/