The main types of leukemia include:
Acute lymphocytic leukemia (ALL)Acute myelogenous leukemia (AML)Chronic lymphocytic leukemia (CLL)Chronic myelogenous leukemia (CML)
There are also other rare forms of the disease. Some types of leukemia are more difficult to treat than others. Your doctor will run tests to determine what kind you have. (1)
Four Main Types of Leukemia
Acute Lymphocytic Leukemia (ALL)
If you have ALL, the cancer affects the lymphocyte cells, white blood cells that normally help fight infections. The bone marrow makes too many immature lymphocytes, and they end up crowding out other blood cells. (2) ALL is an acute cancer, which means it grows quickly. The leukemia cells can spread to the lymph nodes, liver, spleen, brain, or spinal cord, and in men, the testicles. (3) ALL is rare in adults, affecting only about 3,000 adults in the United States each year. But it accounts for about 75 percent of childhood leukemias, making it the most common form of cancer in children. (4) Children younger than 5 have the greatest risk for developing ALL. (5) Children with ALL usually respond better to treatment than adults do. In fact, most deaths from ALL happen in adults. (5)
Acute Myelogenous Leukemia (AML)
AML affects a group of white blood cells called myeloid cells. This type of cancer is sometimes referred to as acute myeloid leukemia, acute myeloblastic leukemia, acute granulocytic leukemia, or acute nonlymphocytic leukemia. This type of leukemia occurs in both children and adults. (5) It’s the most common acute leukemia in adults. The average age of someone with AML is around 68 years old. There are about 20,050 new cases of AML each year in the United States. The cancer is typically fast-growing and requires prompt treatment. (6,9) AML accounts for about 19 percent of childhood leukemias. Children with certain genetic conditions, such as Fanconi anemia, Down syndrome, Bloom syndrome, and Kostmann syndrome, are more likely to develop AML than other kids. (2) RELATED: Essential Facts About Leukemia
Chronic Lymphocytic Leukemia (CLL)
CLL affects lymphocyte cells. It’s typically a very slow-growing cancer. It’s commonly discovered on a blood test done for other reasons, as many people with CLL don’t have symptoms for years. In some cases, CLL progresses very quickly. CLL most often affects older adults and rarely impacts children. The average age of diagnosis is about 70 years old. Each year, there are about 20,000 new cases of CLL in the United States. There are several effective treatment options for people with CLL. Sometimes, a “watch and wait” approach is taken if the cancer is extremely slow growing. (7,13) This rarer type of leukemia typically grows slowly, but sometimes CML can transform into a fast-growing, acute form of leukemia. (8) It usually affects older adults and is very uncommon in children. The average age of someone diagnosed with CML is 64. About 8,860 new cases of CML are diagnosed each year. (14) CML is different from other types of leukemia because it has a specific abnormal chromosome known as the Philadelphia chromosome. This is not an inherited chromosomal abnormality. The Philadelphia chromosome is formed when genetic material is exchanged between chromosomes 9 and 22 during cell division, which results in the development of CML. (10)
Less Common Types of Leukemia
Other, rarer forms of leukemia or related blood cancers include these conditions:
Hairy Cell Leukemia (HCL) This cancer affects the lymphocytes and tends to grow slowly. It gets its name because the cells look hairy under a microscope. About 2 percent of all leukemias are HCL, according to the National Organization for Rare Disorders (NORD). Treatment for HCL is usually successful.Myelodysplastic Syndromes (MDS) MDS is a group of diseases that cause the bone marrow to produce too few normal blood cells. In the past, MDS was considered a preleukemia. Now it’s labeled as a form of cancer. In 1 in 3 people with MDS, the cancer will progress to a fast-growing AML, according to the American Cancer Society.Myeloproliferative Neoplasms (MPN) MPNs occur when a person’s bone marrow makes too many blood cells. There are several types of MPNs, including polycythemia vera, myelofibrosis, and essential thrombocythemia. (11)
Finding Out What Type You Have
If you experience signs and symptoms of leukemia, your doctor might recommend certain tests to see what’s going on. If you do have a blood cancer, your physician will run additional tests to identify what type of leukemia you have. Blood work can tell a doctor a lot about a cancer. Your clinician will examine the amount, size, shape, and patterns of your blood cells to help classify them. Other tests can help identify the type of leukemia you have, too:
A physical examA bone marrow testImaging scansA spinal tapLymph node biopsyChromosome tests
These screening tools can assist your healthcare provider in determining how the cancer is progressing, how aggressive it is, and the best way to manage it. (12)
Why Leukemia Type Matters
Each form of leukemia attacks the body in a slightly different way. Certain types are fast-growing, while others progress slowly. Knowing your type of leukemia can help you and your doctor come up with an individualized and effective treatment plan. This information can also give you a better idea of what your outlook will be. Once you know the type of leukemia you have, ask your doctor for resources on how to find accurate information. Being knowledgeable about the cancer you have can help you make informed decisions.
