Cancer can develop from any cell in the body. Leukemias and lymphomas, for example, are both forms of blood cancer that develop from blood cells. However, they occur in different places within the body, and they may have different causes, symptoms, and treatments. Although leukemia and lymphoma were historically thought to be completely separate diseases, we keep learning about similarities that they share, and we now understand that they can be intricately related.
In order to better understand leukemia and lymphoma, it helps to know more about normal blood cells and where they come from. Blood cells can be primarily 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. Importantly, the bone marrow contains stem cells, which help form all of the different types of blood cells, including:
Once blood cells are made, they may go to different locations throughout 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 in order 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 spend some time growing in the blood, and then enter into the lymph system.
The lymph system is a part of the immune system, which helps the body fight infections. The lymph system includes:
Leukemia primarily affects cells that make up the bone marrow and blood, whereas lymphoma affects cells in the lymph system. A third type of blood cancer, multiple myeloma, develops in the bone marrow from a specific type of white blood cell called a plasma cell. Leukemia can affect red blood cells, white blood cells, or megakaryocytes. Lymphoma only affects lymphocytes.
Although leukemia and lymphoma both develop from blood cells, they can have different characteristics. They have different causes and result in different sets of symptoms. People with leukemia or lymphoma may also receive different treatments.
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. This is a problem because these cancer cells can eventually crowd out normal cells in the bone marrow, blood, and lymph system and prevent the healthy cells from carrying out their necessary tasks.
How do stem cells become damaged? Things like older age, toxic chemicals, smoking, and certain genetic disorders can increase your chances of getting leukemia. Similar factors can also lead to lymphoma. However, there are some additional factors that can increase your likelihood of getting lymphoma, such as taking drugs that suppress the immune system, having health conditions that affect the immune system, or getting certain types of infections.
These risk factors may increase your chance of developing leukemia or lymphoma, but there is no way to know for sure what caused your cancer. 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.
There are many subtypes of leukemia and 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. Leukemias may be lymphocytic (develop from lymphocytes) or myeloid (develop from the cells that eventually form red blood cells, platelets, or other types of white blood cells besides lymphocytes).
On the other hand, lymphoma can be divided into dozens of different subtypes. The two main categories are Hodgkin lymphoma and non-Hodgkin lymphoma.
These two types of cancer can share similar symptoms, including:
Some of the additional symptoms of leukemia include bruising, bleeding, purple spots on the skin, and shortness of breath. Swollen 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 bigger. If you have lymphoma, you may notice lumps in your armpits, on your neck, or in your groin area.
The same types of treatments may be used for both leukemia and lymphoma, such as chemotherapy, radiation, or stem cell transplants. However, a person’s exact treatment will depend on what subtype of leukemia or lymphoma they have, as well as other factors such as their age, cancer stage, and other health conditions.
The more researchers learn about leukemia or lymphoma, the better able they are to treat all types of blood cancers. For example, recent research has led experts to develop antibody medications, referred to 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 in either leukemia or lymphoma that develops from B cells.
In some cases, the line between these two cancers isn’t clear. Leukemia may develop after lymphoma, 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. Additionally, this process can happen the other way around. Sometimes, chronic leukemia changes into a more advanced lymphoma in a process known as Richter’s syndrome.
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 blood cancers, there aren’t as many differences between leukemia and lymphoma. Chronic lymphocytic leukemia (CLL) is a type of slow-growing cancer that affects the lymphocytes. It is the same disease as small lymphocytic lymphoma (SLL): Both cancers develop from the same type of abnormal white blood cell. However, the disease is called CLL (that is, leukemia) if the cancer cells are found in the bone marrow or blood, and is called SLL (lymphoma) if the cells are found in the lymph system.
Do you have leukemia or lymphoma? Getting support from a community can help you deal with your diagnosis, learn to manage your symptoms, and help you understand your condition better. Joining MyLeukemiaTeam or MyLymphomaTeam can provide you with a support network that helps you along your journey. Join in the conversations there or comment below in order to start connecting with others who know what you’re going through.