Leukemia is a type of cancer that affects the blood and bone marrow. It occurs when the DNA of a blood cell becomes damaged, causing the cell to grow and divide uncontrollably. There are several different types of leukemia, some more aggressive than others. The good news is that in many cases, leukemia can be treated and even cured.
What is leukemia?
Leukemia is a cancer of the body’s blood-forming tissues, including the bone marrow and the lymphatic system. In leukemia, abnormal white blood cells are produced in large numbers. These abnormal cells crowd out healthy blood cells in the bone marrow, leading to anemia and an increased risk of infection. There are several different types of leukemia, which are classified based on the type of blood cell that becomes cancerous (lymphocytic or myeloid) and how quickly the disease progresses (acute or chronic).
The four main types of leukemia are:
- Acute lymphocytic leukemia (ALL)
- Chronic lymphocytic leukemia (CLL)
- Acute myeloid leukemia (AML)
- Chronic myeloid leukemia (CML)
What causes leukemia?
The exact cause of leukemia is not known. However, there are several factors that are thought to increase the risk of developing the disease:
- Genetic factors – Certain genetic abnormalities and syndromes are associated with higher leukemia risk.
- Prior chemotherapy or radiation therapy – Past treatment with chemotherapy or radiation can damage bone marrow cells and increase leukemia risk later on.
- Exposure to chemicals – Long-term exposure to high levels of benzene and certain chemicals is linked to increased risk.
- Smoking – Smoking is associated with a small increase in leukemia risk.
- Family history – Having a sibling or parent with leukemia raises risk.
- Down syndrome and other genetic disorders – People with Down syndrome have a higher risk of leukemia.
In most cases of leukemia, the cause is unknown. These types of cancerous changes in the blood cells appear to develop gradually over time.
Signs and symptoms of leukemia
Common signs and symptoms of leukemia may include:
- Fever or chills
- Persistent fatigue, weakness
- Frequent infections
- Losing weight without trying
- Swollen lymph nodes, enlarged liver or spleen
- Easy bleeding or bruising
- Recurrent nosebleeds
- Tiny red spots in skin (petechiae)
- Excessive sweating, especially at night
- Bone pain or tenderness
The signs and symptoms of leukemia can vary across different types. For example, chronic leukemia typically progresses slowly with fewer symptoms at first. Meanwhile, acute leukemia tends to cause symptoms that worsen quickly.
How is leukemia diagnosed?
To diagnose leukemia, doctors will ask about your medical history and symptoms. They will perform a physical exam to look for enlarged lymph nodes, liver or spleen. They will also check for any easy bruising, bleeding or rashes.
If leukemia is suspected, blood tests will be ordered. These may include:
- Complete blood count (CBC) – Measures levels of different cells in the blood
- Peripheral blood smear – Checks for abnormal cells under a microscope
- Bone marrow biopsy and aspiration – Takes a sample of bone marrow to examine cells
- Molecular testing – Identifies certain genes, proteins and chromosome changes in the cancer cells
- Immunophenotyping – Determines exact type of leukemia based on antigens on the surface of abnormal cells
These tests can determine if leukemia is present and classify the type. Doctors will also use imaging tests like CT scans or ultrasounds to see if the lymph nodes, liver and spleen are enlarged.
Can leukemia be cured?
The curability of leukemia depends on the specific subtype as well as certain patient factors. But overall, many cases of leukemia are considered curable with modern treatments. Here is an overview of curability by type:
Acute lymphocytic leukemia (ALL)
ALL is the most common childhood leukemia. Today, about 90% of children with ALL go into remission after initial treatment. Approximately 85% can be cured through therapies like chemotherapy, radiation, targeted drugs and stem cell transplants.
Chronic lymphocytic leukemia (CLL)
CLL mainly affects older adults and grows slowly. While CLL is challenging to cure, survival rates are improving with newer targeted therapies. Patients may live for many years with CLL under treatment.
Acute myeloid leukemia (AML)
AML progresses rapidly and is more common in adults. Intensive chemotherapy can induce remission in many patients. However, AML has a higher risk of returning after treatment. Overall cure rates are between 35-40%.
Chronic myeloid leukemia (CML)
CML typically occurs in adults and has three phases – chronic, accelerated, and blast crisis. Targeted drugs like imatinib have made CML very treatable, with long-term remission possible. Around 70% of patients survive 5 years or more.
Factors affecting leukemia curability
While leukemia is often curable, there are certain factors that affect an individual patient’s chances of being cured:
- Patient age – Younger patients, such as children, tend to have higher cure rates.
- Leukemia type – Some subtypes, like ALL and CML, are more curable.
- Disease progression – The earlier leukemia is caught, the better the outlook.
- Chromosome changes – Certain chromosomal abnormalities mean poorer prognoses.
- Response to treatment – Patients who go into remission with treatment have better cure rates.
- Overall health – Patients in good health can better tolerate aggressive treatment.
Doctors will consider these factors when assessing a leukemia patient’s individual potential for a cure.
How is leukemia treated?
There are a variety of effective treatment options for leukemia. The specific treatments used depend on the type and subtype of leukemia, as well as the patient’s age, health status and other factors. Common treatments include:
Chemotherapy
Powerful anti-cancer drugs are used to kill leukemia cells and induce remission. Chemotherapy may be used systemically or injected into the cerebrospinal fluid.
Targeted therapy
Drugs that specifically target genetic abnormalities in leukemia cells can be very effective. For example, imatinib targets the BCR-ABL gene mutation in CML.
Radiation therapy
High energy beams are used to kill leukemia cells and shrink tumors. Radiation may target the brain, spine or other parts of the body.
Stem cell transplant
First, aggressive chemotherapy or radiation is given to destroy cancerous cells. Then, healthy stem cells from a donor are transfused to restore the bone marrow’s ability to make new blood cells.
Immunotherapy
Medications boost the body’s own immune system to better recognize and kill leukemia cells. Examples include interferon alfa and monoclonal antibodies.
Supportive care
Patients receive additional care to minimize treatment side effects, control pain and maintain nutrition. Blood transfusions and growth factors may be used.
What is the survival outlook for leukemia?
The survival outlook for leukemia varies considerably based on the subtype. However, survival rates have been improving across all types of leukemia. Here are 5-year relative survival rates by common leukemia subtype:
- ALL: About 67% of adults and over 90% of children
- CLL: Around 85%
- AML: Approximately 27% of adults
- CML: Over 70% and improving
With continuous advances in treatments, monitoring and supportive care, survival rates are expected to further improve in the future.
Can leukemia relapse after treatment?
Unfortunately, yes – leukemia can return after a period of remission. This is known as a relapse. The risk of relapse depends on several factors, including:
- Type of leukemia – ALL has higher relapse rates than AML, for example.
- Depth of remission – More leukemia cells lingering raises relapse risk.
- Chromosomal changes – Certain abnormalities mean higher relapse risk.
- Age – Younger patients are more likely to relapse.
- Transplant status – Relapse risk is lower if stem cell transplant was performed.
For patients in remission, regular monitoring and follow-up testing is important to check for potential relapse. If caught early, another round of treatment may return the patient to remission once again.
Can you be fully cured after a leukemia relapse?
Being cured after a relapse is still possible in many cases, depending on the circumstances. With aggressive re-treatment, some patients can still be cured, although the odds are lower compared to initial treatment. The prognosis varies by situation:
- Timing of relapse – Sooner relapse means poorer outcomes.
- Level of remission – Deeper remission prior to relapse is better.
- Leukemia subtype – Some forms have better cure rates after relapse.
- Prior treatment – Effects of previous therapies on bone marrow.
- Age and health – Younger, healthier patients have higher cure rates.
It’s important to discuss your individual chances of being cured after a relapse with your medical team. They will tailor renewed treatment efforts to your specific leukemia situation.
Conclusion
Leukemia was once considered an incurable, fatal disease. But today, many patients can have high hopes of being cured through modern treatments like chemotherapy, targeted drugs, stem cell transplants and immunotherapy. While leukemia can still relapse and resist treatment in some cases, cure rates have significantly improved across all subtypes thanks to medical advancements.
With a personalized approach to care, close monitoring and ongoing leukemia research, outlooks will continue to get brighter in the future. Being declared fully cured of leukemia is becoming an increasingly possible outcome with optimal treatment.