INTRODUCTION The purpose of this guide is to educate and support patients with Hodgkin lymphoma and their caregivers. It is designed to allow them to familiarize themselves with this disease and to become active participants in their healthcare decisions. Chapters in this guide address different issues faced by patients with Hodgkin lymphoma, including what to expect during diagnosis, work-up, and treatment; how to cope with treatment side effects; and what questions to ask doctors, nurses, physician assistants, social workers, and other members of the healthcare team. In addition to this guide, information is available on the Lymphoma Research Foundation’s (LRF’s) website at www.lymphoma.org and the Foundation’s Hodgkin lymphomaspecific website at www.lymphoma.org/HL. The LRF Helpline can also provide additional information and copies of LRF educational and support publications. For Helpline assistance, call (800) 500-9976 or email helpline@lymphoma.org. 7 Understanding Hodgkin Lymphoma Chapter 1: Understanding the Disease Hodgkin lymphoma (HL) is a type of cancer that affects specialized white blood cells called lymphocytes. Lymphocytes work together with other cells in the immune system to defend the body against invasion by bacteria, viruses, parasites, and other foreign substances. Lymphocytes travel in the bloodstream and in another network of vessels called the lymphatic system. Lymphocytes are also found in specialized structures called lymph nodes, in the bone marrow, and in the spleen. Lymph nodes are part of the lymphatic system and typically are the sites in which the body develops an immune response to viruses and bacterial infections. This chapter explains these and other terms that will help people understand HL and how it affects a person’s health. A better understanding of the disease may allow patients to be active participants in their care. What Is Cancer? The body is made up of many different types of specialized cells that are organized into tissues and organs that perform the tasks needed to sustain life. To keep the body running smoothly, cells in the body grow, work, and multiply in a very controlled fashion. All normal cells have a limited lifespan. A self-destruct mechanism is triggered when cells become senescent (too old) or get damaged; this process is called apoptosis or programmed cell death. However, sometimes damage to the genetic material (DNA) of a cell gives it the ability to override this self-destruct mechanism and allows the cell to continue to live and grow indefinitely, making the cell “immortal” in many ways. Unless the body’s immune system gets rid of these abnormal cells, they can become cancerous. Part 1 — Learning the Basics Learning the Basics 8 Part 1 Cancer, or malignancy, is a disease in which abnormal cells gain the ability to multiply uncontrollably and also may develop defects in apoptosis (programmed cell death). When these cells accumulate, they form a mass called a tumor that can interfere with normal organ function. HOW CANCER FORMS INSIDE THE BODY Normal cell division Groups of abnormal cells may form tumors Cancer cell division Damaged or senescent cell Damaged cell does not self-destruct, and starts to multiply Programmed cell death (apoptosis) 9 Understanding Hodgkin Lymphoma Most cancers are named after the organ or cell type of their origin. For example: ■ A cancer that started in the pancreas is called pancreatic cancer. ■ A cancer of the lymphocytes is called a lymphoma or lymphocytic leukemia depending on whether the cancerous lymphocytes reside primarily in the lymph nodes and other lymphatic tissues (lymphoma) or primarily in the bone marrow and the blood (lymphocytic leukemia). What Are the Different Types of Blood Cells?