Cancer is the uncontrolled growth and multiplication of cells that spreads throughout the body. Two kinds of cancer, lymphoma and leukemia, are similar because they both affect blood cells. Their origins, causes, symptoms, and treatments make them separate conditions. However, the more we learn about lymphoma and leukemia, the more we understand that they can be intricately related.
To better understand blood cell abnormalities like leukemia and lymphoma, it helps to learn about normal blood cells. Blood cells are usually found in the bone marrow, the bloodstream, and the lymph system.
Bone marrow is a type of tissue that contains different types of cells and blood vessels. It is located inside certain types of bones, including the bones found in your legs and hips. The bone marrow produces stem cells, which help form different types of blood cells, including:
Once blood cells are made, they may go to different parts of the body. Some stay in the bone marrow, while others start circulating in the bloodstream. Blood has many important roles. It can:
Healthy blood cells are needed to carry out these different tasks.
Specific types of white blood cells called lymphocytes develop in the bone marrow. Lymphocytes consist of B cells, T cells, and natural killer cells. These cells grow in the blood and then enter into the lymphatic (lymph) system.
The lymphatic system is a part of the immune system, which helps the body fight infections. The lymph system includes:
Although lymphoma and leukemia both come from blood cells, they develop in different types of cells. They can also have different causes, symptoms, and paths to diagnosis.
Lymphoma primarily grows from lymphatic cells in the lymph system, whereas leukemia affects cells that make up the bone marrow and blood. While lymphoma only affects lymphocytes, leukemia can affect red blood cells, white blood cells, or megakaryocytes.
Normal blood cells don’t last forever. Cells become damaged over time, and older blood cells may not work as well as younger ones. The body typically removes or recycles old blood cells and creates new ones to take their place.
When stem cells are damaged, they may start producing abnormal, cancerous blood cells. These cells may grow too quickly, or they may not die when they should. These cancer cells can eventually crowd out normal cells in the bone marrow, blood, and lymph system, preventing the healthy cells from carrying out their tasks.
How do stem cells become damaged? Things like older age, exposure to toxic chemicals, smoking, and certain genetic disorders increase the chances of cells mutating and developing into lymphoma or leukemia. Other factors can also increase your likelihood of developing lymphoma, such as taking drugs that suppress the immune system, having health conditions that affect the immune system, or having certain types of infections.
While risk factors may increase your chance of developing either kind of cancer, there is no way to know for certain what causes these cancers. Some people with many risk factors don’t develop blood cancer, and some people who are diagnosed with blood cancer don’t have any risk factors.
Leukemia and lymphoma can be categorized by subtypes. Lymphoma can be divided into dozens of different types. The two main categories are Hodgkin lymphoma and non-Hodgkin lymphoma.
Leukemias may be described as either acute (fast-growing) or chronic (slow-growing). They are also classified based on which specific cell type they come from — either lymphocytic (develops from lymphocytes to become certain types of white blood cells) or myeloid (develops from the cells that eventually form red blood cells, platelets, or other types of white blood cells besides lymphocytes). The main types of leukemia include acute myeloid leukemia, acute lymphoblastic leukemia (also called acute lymphocytic leukemia), chronic myeloid leukemia, and chronic lymphocytic leukemia.
These two types of cancer can share similar symptoms, including:
Enlarged lymph nodes are one of the most common symptoms of lymphoma. This is because lymphoma causes cancer cells to build up inside the lymph nodes, making them swollen. If you have lymphoma, you may notice swollen lymph nodes in your armpits, on your neck, or in your groin area. MyLymphomaTeam members also discuss persistent signs and symptoms like numbness and tingling, back pain, anemia (low red blood cell count), and bone pain.
Some other symptoms of leukemia include bruising, bleeding, purple spots on the skin, and shortness of breath. MyLeukemiaTeam members often discuss fatigue, pain, and weakness as their most noticeable symptoms.
Because leukemia and lymphoma have different symptoms and origins, doctors may use many tools to diagnose and distinguish the two forms of cancer. For both lymphoma and leukemia, a physician may conduct tests to look for signs of blood cancer, including:
The process of diagnosing lymphoma may also include lymph node biopsy, which requires surgically removing a piece of lymph node tissue and testing it for abnormal cells. For some people, routine blood tests will show initial signs of asymptomatic lymphoma or leukemia. For others, preexisting symptoms will lead them to see an oncologist.
Treatments for both kinds of cancers include chemotherapy, radiation, or stem cell transplants. However, a person’s exact treatment will depend on what subtype of lymphoma or leukemia they have, as well as their age, cancer stage, and other health conditions.
The more researchers learn about lymphoma and leukemia, the better able they are to treat all types of blood cancers. For example, recent research advances have led to the development of antibody medications, known as immunotherapy or targeted therapies. These treatments contain molecules that specifically recognize and attack B cells or T cells. An antibody that kills B cells could possibly be used to treat either lymphoma or leukemia that develops from B cells.
In some cases, the line between these two cancers isn’t clear. Lymphoma may develop after leukemia, or vice versa. It’s also possible for a person to have both, either at the same time or one after the other.
Sometimes, one type of blood cancer can change into another — usually more aggressive — type of blood cancer. For example, one common form of slow-growing lymphoma called follicular lymphoma can become faster-growing acute lymphoblastic leukemia. This process can also happen the other way around. Sometimes, chronic leukemia changes into a more advanced lymphoma in a process known as Richter’s transformation. One member of MyLeukemiaTeam reported, “I saw the dermatologist today. He took a biopsy thinking I may have lymphoma on my skin.”
Sometimes, the treatment for one cancer can cause another cancer. People who have lymphoma often receive treatments like chemotherapy and radiation. These treatments can increase a person’s chances of developing leukemia later on.
Among some types of leukemia and lymphoma, the differences are small to none. Small lymphocytic lymphoma (SLL) is a type of slow-growing cancer that affects the lymphocytes. It is the same disease as chronic lymphocytic leukemia, or CLL: Both cancers develop from the same type of abnormal white blood cell. However, the disease is called SLL (that is, lymphoma) if the cells are found in the lymph system. It’s called CLL (leukemia) if the cancer cells are found in the bone marrow or blood.
Do you have lymphoma or leukemia? Getting support from a community can help you deal with your diagnosis, learn to manage your symptoms, and understand your condition better. Joining MyLymphomaTeam or MyLeukemiaTeam can provide you with a support network to help you along your journey.
Do you have more questions about the differences between leukemia and lymphoma? Comment below to discuss with others who know what you’re going through.