Leukemia is a blood cancer that causes the production of normal blood cells to go haywire.
Leukemia is a broad term for cancers of the blood cells that originate in the bone marrow – the soft, spongy tissue inside bones where blood cells are produced. In a healthy body, bone marrow stem cells mature into healthy white blood cells, red blood cells, and platelets.
In leukemia, a genetic mutation causes blood cells (usually white blood cells) to develop abnormally, multiply uncontrollably, and crowd out the healthy cells.
This overproduction of abnormal cells impairs the body’s ability to fight infection, carry oxygen, and control bleeding, leading to the signs and symptoms of the disease.
Classification and Types
Leukemia is classified in two primary ways: by its speed of progression and by the type of cell affected.
Speed of Progression
- Acute Leukemia: The abnormal cells are immature blood cells (blasts) that multiply rapidly, and the disease progresses quickly. It requires immediate, aggressive treatment.
- Chronic Leukemia: Involves more mature blood cells that replicate or accumulate more slowly and can function normally for a period. Symptoms may not appear for years, and the disease typically worsens gradually.
Type of Cell Affected
- Lymphocytic (or Lymphoblastic) Leukemia: Affects lymphoid cells, which are part of the immune system and typically develop into lymphocytes (a type of white blood cell).
- Myelogenous (or Myeloid) Leukemia: Affects myeloid cells, which normally give rise to other types of white blood cells, red blood cells, and platelet-producing cells.
These classifications combine to form the four main types of leukemia:
- Acute Lymphocytic Leukemia (ALL): Most common type of cancer in children, though it also affects adults. Over 6,000 people are diagnosed with ALL each year. The overall five-year relative survival rate for acute lymphocytic leukemia (ALL) is approximately 72% in the United States. However, this rate varies significantly by age, with children having a much higher survival rate than adults.
- Acute Myeloid Leukemia (AML): One of the most frequently diagnosed acute leukemias in adults in the United States, and there are around 20,000 newly diagnosed AML cases each year. The overall five-year relative survival rate for acute myeloid leukemia (AML) in the U.S. is approximately 33%*. This rate, however, is heavily dependent on age and other prognostic factors, as the disease is more common and has a worse prognosis in older adults.
- Chronic Lymphocytic Leukemia (CLL): Most common chronic leukemia in adults, with around 24,000 new diagnoses each year. CLL often affects older individuals. The overall five-year relative survival rate for chronic lymphocytic leukemia (CLL) in the United States is close to 90%. This statistic has continually improved over the last few decades due to treatment advancements.
- Chronic Myeloid Leukemia (CML): Primarily affects adults and is characterized by a specific genetic abnormality called the Philadelphia chromosome. Around 10,000 new CML cases are diagnosed each year. The overall five-year relative survival rate for chronic myeloid leukemia (CML) is approximately 70% in the United States. Thanks to the introduction of targeted therapies known as tyrosine kinase inhibitors (TKIs), outcomes have improved dramatically, and many patients can expect a near-normal life expectancy. With continuous TKI therapy, the 10-year survival rate for patients is approaching 90%, with many patients dying from unrelated causes rather than the leukemia itself.
*Note that Jackson had a particularly aggressive form of AML with a FLT-3 mutation. As you can see, AML survival rates lag dramatically behind that of other types of leukemia, and the prognoses are much worse for some mutations. This is one of the things we intend to change, by focusing on research into these hard-to-treat leukemia variants. Please help us get there!
Common Symptoms
Symptoms vary depending on the type and stage of leukemia, but they often result from a lack of normal, healthy blood cells. Common symptoms include:
- Fatigue, weakness, and pale skin (due to anemia/low red blood cells)
- Frequent or recurrent infections and fever (due to dysfunctional white blood cells)
- Easy bruising and bleeding, including nosebleeds and bleeding gums (due to low platelets)
- Tiny red spots on the skin (petechiae)
- Unexplained weight loss
- Swollen lymph nodes, liver, or spleen
- Bone or joint pain
- Excessive sweating, especially at night
- Pale skin and lips (this was the most noticeable initial symptom we noticed with Jackson)
Treatments
Treatment for leukemia varies significantly depending on the type of leukemia (acute or chronic), the patient’s age and overall health, and the presence of specific genetic mutations. The main treatment options typically include:
- Chemotherapy: The primary treatment for most types of acute leukemia (ALL and AML), using powerful drugs to kill cancer cells throughout the body. Chemotherapy is typically administered in phases (induction, consolidation, and maintenance), often over a period of several months or more.
- Targeted Therapy: This uses drugs that focus on specific abnormalities within cancer cells to block their growth and spread, often with fewer side effects than traditional chemotherapy. These treatments target proteins that control how cancer cells grow, divide, and spread. Targeted drug therapy is the main treatment for chronic myeloid leukemia (CML) and a key part of therapy for specific subtypes of ALL and AML that have targetable gene mutations.
- Combination Therapy: Chemotherapy is often combined with one or more targeted therapies to improve clinical outcomes. Different types of leukemia require different combinations of therapies. For a complete list of all currently approved drugs, see Drugs Approved for Leukemia.
- Immunotherapy: These treatments help the body’s own immune system recognize and attack cancer cells.
- CAR T-cell Therapy is a specialized immunotherapy where a patient’s T-cells are genetically modified in a lab to target and destroy leukemia cells, then infused back into the body. This is an option for certain cases of relapsed or refractory ALL and CLL, and is also being tested as initial stage treatment option. As of this writing, CAR-T is generally not considered an option for AML (yet another thing we intend to change with your support).
- Monoclonal Antibodies are lab-made immune proteins that attach to specific proteins on leukemia cells (like CD20 or CD33), either killing them directly or flagging them for the immune system.
- Stem Cell Transplant (Bone Marrow Transplant): This procedure replaces diseased bone marrow with healthy blood-forming stem cells (either from a donor or the patient’s own previously collected cells) after high-dose chemotherapy or radiation therapy has destroyed the cancerous marrow. It may be used for higher-risk leukemia (such as certain types of AML), when the disease does not respond to standard treatments, or if it relapses.
- Radiation Therapy: Uses high-energy beams to kill leukemia cells or shrink swollen organs (like the spleen or lymph nodes). It is often used to treat or prevent the spread of leukemia to the central nervous system or as preparation for a stem cell transplant.
- Watchful Waiting: For many patients with early-stage chronic leukemia (especially CLL) that is not causing symptoms, doctors may recommend close monitoring without immediate active treatment, as early treatment does not improve survival outcomes in these cases.
Clinical Trials
Clinical trials are essentially scientific testing of new medications. They are a crucial part of advancing leukemia treatment, offering patients access to cutting-edge and investigational therapies. For comprehensive information, explore The Mayo Clinic’s list of leukemia clinical trials.