Hodgkin Lymphoma is a type of a cancer of the immune cells of the blood system.1 Certain white blood cells called lymphocytes are normal parts of the immune system of the body, the system responsible for recognizing and mounting a defense against germs (bacteria, viruses, fungi, etc.). Lymphocytes are white blood cells that circulate in the blood stream as well as migrate to areas of the body where germs enter such as the lining of the mouth, nares, throat, intestinal tract and skin. In addition, lymphocytes collect in small, bean shaped structures called lymph nodes located throughout the body, as well as in the spleen, bone marrow and a special organ in the chest called the thymus. Those organs constitute the lymphatic system. Lymphocytes are a major source of the defense system against germs that enter the body.
Hodgkin Lymphoma is a rare cancer that occurs in ~2.5 people per 100,000/year in the US. Incidence rates vary around the world but are similar to the US in most countries ranging from 1-4/100,000.2 This means there are about 9,000 estimated new cases in the US in 2023.2
Hodgkin Lymphoma is believed to develop from a lymphocyte that has an error in the DNA program of the cell that leads to an advantage in survival and abnormal growth. This cell, called a Reed Sternberg cell, is the cancer cell of Hodgkin Lymphoma. Reed Sternberg cells also produce substances called cytokines, which further promote the growth of Reed-Sternberg cells. Scientists are not certain of the cause that leads a normal lymphocyte to become a malignant Reed-Sternberg cell. More on this topic can be found at the American Cancer Society website at https://www.cancer.org/cancer/Hodgkin-lymphoma.html.
There are two kinds of Hodgkin Lymphoma- Classical Hodgkin Lymphoma and Lymphocyte Predominant Hodgkin Lymphoma. Hodgkin Lymphoma usually starts in one of the lymphatic nodes and over time spreads, progressively, to other sites. Symptoms are usually enlargement of one or many regional areas of lymphatic tissue (enlarged lymph nodes, enlarged spleen, etc.). Other symptoms, called “B” symptoms can occur which include fevers that persist or come and go, drenching night sweats, and weight loss (>10% of body weight). These symptoms are significant to the prognosis and staging of the disease. Other symptoms such as fatigue, generalized itching, and decreased appetite may occur but are not indicative of Hodgkin Lymphoma.
A diagnosis of Hodgkin Lymphoma results from a surgical sampling of the enlarged lymph tissue and examination by a tissue expert called a pathologist. Staging (determination of the extent of spread in the body) is determined with radiology testing including a CT scan and a PET (Positron Emission Tomography) scan. Treatment is chemotherapy and regimens are selected by a medical oncologist (cancer specialist) in collaboration with the patient based on stage, symptoms and type (classical vs. Lymphocyte Predominant). Radiation treatments and immunotherapies may also be part of the treatment regimen.
Staging
Hodgkin Lymphoma disease extent in the body is categorized by a system called staging. A common staging system used is called the Ann Arbor Staging system.
Principal stages
The principal stage is determined by location of the tumor3:
- Stage I indicates that the cancer is located in a single region, usually one lymph node and the surrounding area. Stage I often will not have outward symptoms.
- Stage II indicates that the cancer is located in two separate regions, an affected lymph node or organ and a second affected area, and that both affected areas are confined to one side of the diaphragm—that is, both are above the diaphragm, or both are below the diaphragm.
- Stage III indicates that the cancer has spread to both sides of the diaphragm, including one organ or area near the lymph nodes or the spleen.
- Stage IV indicates diffuse or disseminated involvement of one or more extralymphatic organs, including any involvement of the liver, bone marrow, or nodular involvement of the lungs.
Treatment for Hodgkin Lymphoma is based upon staging and absence (“A”) or presence (“B”) of specific B symptoms. More advanced Disease (Stages III and IV and with B symptoms) is treated with more aggressive chemotherapy than disease that is more localized (Stages I-II). For more information on treatment regimens please refer to the American Cancer Society site https://www.cancer.org/cancer/odgkin-lymphoma.html.
