Hodgkin’s Lymphoma: An Environmental Scan
Table of Contents
3.0 FINDINGS FROM THE ENVIRONMENTAL SCAN
The following section of the report provides an overview according to specified topic areas regarding Hodgkin’s Lymphoma. Initially, the section begins by defining the classification of the different types of HL followed by a brief presentation of the differences between HL and non-Hodgkin’s lymphoma. Next, a discussion of the epidemiology and the various risk factors associated with Hodgkin’s Lymphoma and finally a focus on the symptoms diagnosis, prognosis and treatment including conventional, complementary and alternative therapies.
In the broadest sense, cancer occurs in the body when the DNA within a cell results in an abnormality. The changes to normal DNA are from either an inherited condition programmed within the cell or an exposure within the environment (e.g., a carcinogenic) that creates an abnormality. Under normal processes, the body’s immune system is able to identify and destroy such abnormal cells; however, when normal processes do not occur, the proliferation of the cancer cells continues in an uncontrollable rate, which over time produces a cancerous tumor. When this occurs within the lymphatic system of the body, it is known as a lymphoma.
The immune system is responsible for ensuring that bacteria and viruses or any foreign entities along with mutations within the body are identified and destroyed, thereby maintaining health. The immune system is composed of various cells, tissue and organs. Within the larger immune system is the lymphatic system, which is integral to overall immune functioning. The lymphatic system is found throughout the body and consists of organs, nodes, tissue and the lymph fluid itself. This fluid is carried throughout the body by a network of tubes and lymph vessels. Lymph nodes, which are found primarily in the neck, under the arms and in the groin area filter the lymph fluid and remove unwanted material such as bacteria, parasites, viruses and toxins.
Specific components of the lymphatic system that recognize and destroy undesirable material in the body are the lymphocytes. Lymphocytes are a particular type of white blood cell that forms in bone marrow, spleen and lymph nodes. Lymphocytes circulate throughout the body in both the blood and through various lymph vessels. There are two major categories of lymphocytes known as B and T lymphocytes. B lymphocytes mature into plasma and very particular proteins called antibodies. Such antibodies are crucial for immune function as they react with specific types of invaders. In other cases, where the undesirable cell is formed within the body’s own cells and can avoid detection by the B lymphocytes, the T-lymphocytes are able to identify situations where the body’s own cells pose a risk and the T-lymphocytes take over to destroy abnormalities directly. Specifically, T-lymphocytes attack viral invaders and destroy abnormal cells of which cancer cells are one type (see Appendix D: The Lymphatic System) for a comprehensive look at this system).
When a cancer develops within the lymphatic system it is termed a lymphoma and there are approximately 67 sub-types currently identified. In general, all lymphomas are divided into either Hodgkin’s lymphoma or non-Hodgkin’s lymphoma. Hodgkin’s lymphoma occurs when a lymphocyte (most frequently a B-lymphocyte) becomes abnormal and specifically, the abnormal cell contains Reed-Steenberg (RS) cells along with other types of abnormal and inflammatory cells. Each cancer cell, such as the RS cells express a particular antigen. An antigen is a chemical that is associated with some entity in the body, such as a virus, bacteria or cancer cell that denotes it to the immune system as foreign substance. Normal functioning lymphocytes in the immune system recognize the antigen as an invader to the body and produce an antibody specific to each antigen facilitating the process of identifying and destroying potentially harmful invaders. In the case of classical Hodgkin’s lymphoma, the cancer cells continue to divide and grow at a rapid rate overwhelming the immune system’s ability to use normal processes to eliminate the cancer cells. Conversely, non-Hodgkin’s lymphoma (NHL) is also a cancer found within the lymphatic system; however, most NHL’s are B-cell types with diffuse large B-cell and follicular lymphomas being the most common and are indolent or slow growing versus aggressive types of cancer respectively.