What is leukemia?
Leukemia is a type of cancer that affects the blood and bone marrow. It occurs when the DNA of a blood cell becomes damaged and causes the cell to grow and divide uncontrollably. There are several different types of leukemia:
Acute leukemia
Acute leukemia develops and worsens quickly. The abnormal blood cells crowd out the healthy cells in the bone marrow, preventing the production of normal blood cells. This can lead to anemia, easy bleeding or bruising, and a compromised immune system. There are two main types of acute leukemia:
– Acute lymphoblastic leukemia (ALL): This affects the white blood cells called lymphocytes. It is the most common type of childhood leukemia.
– Acute myeloid leukemia (AML): This affects myeloid cells that normally develop into red blood cells, platelets, and white blood cells (other than lymphocytes). It occurs more commonly in adults.
Chronic leukemia
Chronic leukemia develops slowly over time. There are two main types:
– Chronic lymphocytic leukemia (CLL): This also affects lymphocytes and tends to occur mostly in older adults. It generally progresses slowly.
– Chronic myeloid leukemia (CML): This type affects myeloid cells and progresses slowly at first before speeding up without treatment. It occurs mainly in adults.
Additional types
Other, rarer types of leukemia include hairy cell leukemia, T-cell prolymphocytic leukemia, and adult T-cell leukemia. These affect specific types of white blood cells.
What causes leukemia?
The exact causes of leukemia are not fully understood. However, there are certain risk factors that can increase the chances of developing leukemia:
– Previous cancer treatment with chemotherapy or radiation therapy
– Exposure to high levels of radiation
– Genetic conditions like Down syndrome
– Smoking cigarettes
– Exposure to certain chemicals like benzene
– Having a weakened immune system due to conditions like HIV/AIDS
– Family history of blood cancers or genetic mutations
In most cases of leukemia, the DNA mutations that lead to cancer occur randomly after birth and without a specific cause. But the risk factors above can make these mutations more likely.
What are the symptoms of leukemia?
Symptoms of leukemia can vary depending on the type, but common ones include:
– Fatigue and weakness
– Frequent infections
– Fevers and chills
– Bruising or bleeding easily
– Bone and joint pain
– Swollen lymph nodes
– Losing weight without trying
– Frequent or severe nosebleeds
– Petechiae (tiny red spots under the skin)
The abnormal blood cells crowd out the healthy cells in the bone marrow, leading to low levels of normal white blood cells, red blood cells, and platelets. This causes the symptoms of anemia, easy bleeding/bruising, and frequent infections.
How is leukemia diagnosed?
If leukemia is suspected based on symptoms, a doctor will order blood tests and a bone marrow biopsy. This involves taking a sample of bone marrow, usually from the hip bone, and examining it for abnormalities.
Blood tests look for the presence of abnormal cells. High white blood cell counts or low red blood cell and platelet counts can indicate leukemia.
The bone marrow biopsy gives the most definitive leukemia diagnosis. Looking at the bone marrow sample under a microscope, a doctor can identify excessive amounts of abnormal cells.
Other tests like lumbar punctures, CT scans, or MRIs may be done to determine if the leukemia has spread to the spinal fluid or organs. Detecting specific genetic mutations in the cancerous cells can also help classify the type of leukemia.
What are the treatment options for leukemia?
Treatment options for leukemia include:
Chemotherapy
Chemotherapy uses powerful drugs to kill cancer cells. It is typically the first treatment used and may be given in different combinations and cycles. For fast-growing acute leukemias, the goal is to induce a remission.
Targeted therapy
These drugs target specific weaknesses in cancer cells, unlike traditional chemotherapy which targets all rapidly dividing cells. Targeted drugs are used mainly for chronic leukemias.
Radiation therapy
Radiation aimed at the brain and spinal cord can be used to kill cancerous cells. This may be used to prevent the spread of leukemia to the nervous system.
Stem cell transplant
Also called bone marrow transplant, this procedure allows the patient to receive healthy stem cells from a matched donor. It is used often after chemotherapy to restore the bone marrow’s ability to produce normal blood cells.
Immunotherapy
Medications boost the body’s immune system to better target cancer cells. This is used mainly in certain types of acute leukemia.
The treatment plan is tailored for each patient based on the leukemia type, health status, and other factors. Oftentimes a combination of therapies is used.
What is the prognosis for leukemia?
The prognosis for leukemia depends heavily on the specific type. According to the American Cancer Society:
– The 5-year survival rate for ALL is about 69% for children and 25% for adults.
– The 5-year survival rate for AML is about 65% for children and 27% for adults.
– For CLL, the 5-year survival rate is about 83%.
– For CML, the 5-year survival rate is around 66%.
Prognosis is generally better for chronic leukemias compared to acute leukemias. Early diagnosis, younger age, good response to treatment, and overall health are factors that can improve prognosis.
Advancements in treatments have greatly improved survival rates over the past several decades. Monitoring for recurrence is important after treatment as leukemia can return in some cases.
Is leukemia fatal?
In the past, leukemia was often fatal within a few years of diagnosis. Now, major strides have been made in treatments.
For acute leukemias like ALL and AML, timely and aggressive treatment is critical. But overall 5-year survival rates are now around 60-70% for children and 25-30% for adults.
Chronic leukemias like CLL and CML progress much slower. With continuous treatment, many patients can manage a chronic leukemia for years before it becomes life-threatening. The 5-year survival rate for chronic leukemias is over 80%.
So while leukemia is still a very serious diagnosis, the majority of leukemia types are no longer an immediate death sentence as they once were. Continued research to improve therapies and survival rates provides hope. However, relapse remains a concern requiring close monitoring after treatment.
Conclusion
In summary, leukemia is a serious blood cancer that affects the bone marrow’s ability to produce normal blood cells. It has several types that can be acute or chronic. Survival rates vary significantly based on the leukemia type, age, and response to treatment.
Major treatment options include chemotherapy, radiation, stem cell transplants, targeted drugs, and immunotherapy. While leukemia is still potentially fatal if untreated, modern treatments have greatly improved the prognosis for many patients when caught early. Continued research provides hope for finding additional therapies and cures.
| Type | 5-year survival rate |
|---|---|
| ALL (children) | 69% |
| ALL (adults) | 25% |
| AML (children) | 65% |
| AML (adults) | 27% |
| CLL | 83% |
| CML | 66% |