Leukemia is a type of blood cancer that originates in the bone marrow, where blood cells are made. It results from mutations in the DNA of developing blood cells, causing them to grow and divide uncontrollably. While leukemia is often thought of as a childhood cancer, it can also occur in adults and even in the elderly. So can leukemia first appear later in life, or does it only affect children and younger adults?
What is leukemia?
Leukemia is not a single disease, but rather a group of blood cancers that affect the bone marrow and blood. There are several main types of leukemia:
Acute leukemia
– Acute lymphoblastic leukemia (ALL): Develops from lymphocytes, a type of white blood cell, and progresses rapidly. Most common type of childhood leukemia.
– Acute myeloid leukemia (AML): Develops from myeloid cells that form red blood cells, platelets, and most white blood cells. Can occur at any age.
Chronic leukemia
– Chronic lymphocytic leukemia (CLL): Most common type of adult leukemia. Slowly progresses from lymphocytes.
– Chronic myeloid leukemia (CML): Uncommon type that starts in myeloid cells. Typically occurs in adults.
Other types
There are also more rare types of leukemia like hairy cell leukemia, T-cell prolymphocytic leukemia, large granular lymphocytic leukemia, and others. The main classes are acute, which progresses quickly, and chronic, which progresses slowly.
What causes leukemia?
In most cases, the exact cause of leukemia is unknown. However, there are several risk factors that are associated with increased chances of developing different types of leukemia:
– Genetic conditions like Down syndrome
– Previous chemotherapy or radiation therapy
– Exposure to high levels of radiation
– Smoking
– Family history of leukemia
– Exposure to certain chemicals like benzene
– Blood disorders like myelodysplastic syndrome
The development of leukemia is a multi-step process that requires multiple mutations in cells over time. Exposure to the risk factors above likely contributes to some of these mutations. However, in many cases the mutations occur from random chance as well.
Can you get leukemia as an adult or senior?
Yes, absolutely. While acute lymphocytic leukemia (ALL) and acute myeloid leukemia (AML) more commonly affect children and younger adults, chronic leukemias like CLL and CML mostly occur in older adults.
Here is an overview of the typical age distributions for different leukemia types:
Acute lymphocytic leukemia (ALL)
ALL accounts for approximately 80% of all childhood leukemia cases. The typical age range is between 2-5 years old. About 90% of cases occur before the age of 18. Adult cases over the age of 18 make up the remaining 10% of ALL diagnoses and typically occur between the ages of 30-39. Cases over the age of 40 are rare.
Acute myeloid leukemia (AML)
The average age at diagnosis for AML is 68 years old. However, about 15-20% of cases occur in patients under the age of 45. Rates increase steadily with age over 45.
Chronic lymphocytic leukemia (CLL)
This is the most common type of adult leukemia. The average age at diagnosis is 70 years old. It rarely affects children or adolescents. About 90% of CLL cases occur over the age of 50.
Chronic myeloid leukemia (CML)
The average age at diagnosis for CML is 64 years old. Only 10% of cases occur in patients under the age of 20. Rates increase steadily throughout adulthood and old age.
So while acute leukemias are more common in the young, chronic types of leukemia primarily impact older adults over 50. Leukemia can show up later in life.
What are the symptoms of adult leukemia?
The symptoms of leukemia may vary depending on the type. However, common general symptoms in adults include:
– Fatigue and weakness
– Shortness of breath during activity
– Weight loss and loss of appetite
– Fever and chills
– Night sweats
– Bone and joint pain
– Bleeding gums
– Petechiaes (small red/purple spots under skin)
– Swollen lymph nodes
– Easy bruising or bleeding
– Frequent infections
Symptoms result from having too many abnormal, non-functioning immature blood cells and not enough normal functioning blood cells like red blood cells, platelets, and normal white blood cells.
Many of these symptoms are vague and could be caused by other medical conditions. Seeking prompt medical evaluation is important for diagnosis.
How is leukemia diagnosed in adults?
If leukemia is suspected based on risk factors and symptoms, a doctor will order blood tests and a bone marrow biopsy to confirm the diagnosis.
Blood tests
A complete blood count (CBC) is usually the first test. It measures levels of the different types of cells in the blood like red blood cells, white blood cells, and platelets. With leukemia, there are typically too many white blood cells and not enough red blood cells and platelets.
The CBC results may show:
– High white blood cell count
– Low red blood cell count (anemia)
– Low platelet count (thrombocytopenia)
– Immature blood cells (blasts) circulating in the blood
Bone marrow biopsy
This test uses a large needle to remove a sample of bone marrow, usually from the hip bone. The bone marrow is where blood cells are produced.
In leukemia, the bone marrow contains too many immature white blood cells. Examining the bone marrow under the microscope allows doctors to determine the type of leukemia cells, such as myeloid or lymphocytic cells.
Other lab tests like genetic testing and immunophenotyping may also be used to confirm the diagnosis.
How is adult leukemia treated?
Treatment options for leukemia depend on the type of leukemia, the patient’s age and health status, and whether it is a first diagnosis or relapse. Common treatments include:
Chemotherapy
Uses anti-cancer drugs to kill leukemia cells. May be used systemically or injected into the spinal fluid or brain. Often the first treatment used. Can cause significant side effects.
Targeted therapy
Drugs that target specific abnormalities in leukemia cells. Examples are imatinib for CML and rituximab for CLL. Often have less severe side effects than chemotherapy.
Stem cell transplant
Allows the use of very high-dose chemotherapy to kill all cells in the bone marrow. Then replaced with healthy stem cells from a donor. Carries risks of serious infection and graft-versus-host disease.
Radiation therapy
High energy beams used to kill cancer cells. May be used if cancer has spread to the brain or spinal cord or other parts of the body. Can have side effects like fatigue and skin irritation.
Surgery
Surgery to implant a port for delivering chemotherapy or medications or to relieve spleen enlargement. Splenectomy increases infection risk.
Treatment often lasts for years. Maintenance therapy and close monitoring for relapse are usually necessary after initial treatment.
What is the prognosis for older adults with leukemia?
The prognosis for leukemia depends heavily on the patient’s age, health, type of leukemia, and certain cancer cell features. Some key prognosis factors include:
Age
Younger adults generally have a better prognosis than older seniors for leukemia survival. Treatment tolerance also declines with age.
Health status
Seniors with other chronic health conditions like heart disease, lung disease, diabetes, and kidney disease have a worse prognosis compared to otherwise healthy individuals. Good functional ability leads to better outcomes.
Leukemia type and features
In general, chronic leukemias like CLL have better survival rates than acute leukemias. Cell characteristics like specific chromosome/gene mutations impact prognosis.
According to American Cancer Society statistics:
– 5-year survival for AML is 28% for those over 65 years old
– 5-year survival for CLL is 84% for those over 65 years old
However, survival rates have improved over time with newer treatments. Stem cell transplants and targeted drugs lead to better outcomes for some patients.
Can you prevent adult leukemia?
There is no known definitive way to prevent leukemia. Since the causes are not fully understood, prevention is difficult. However, avoiding known risk factors may lower risk:
– Avoid tobacco smoking
– Limit radiation exposure from X-rays or CT scans if possible
– Use protective equipment around known leukemia-causing chemicals like benzene
– Treat viral infections like HIV that raise leukemia risk
– Maintain a healthy weight and be physically active
Lowering exposure to possible risk factors through healthy lifestyle choices is reasonable, but cannot guarantee leukemia prevention. Early detection and treatment leads to better survival.
Conclusion
Leukemia does not exclusively affect children and young adults – it can show up later in life as well. Chronic leukemias like CLL and CML primarily impact older adults over the age of 50 and rates increase with age. Acute leukemias occur more often in younger patients but can still appear in older adults in rare cases.
Leukemia causes non-specific symptoms like fatigue, infections, bleeding/bruising easily, and bone pain. Blood tests and bone marrow biopsy confirm the diagnosis. Treatment options include chemotherapy, radiation, targeted drugs, stem cell transplants, and splenectomy surgery depending on the type and characteristics of the leukemia.
Prognosis varies by age, health, and leukemia type. Chronic leukemias have better survival rates than acute leukemias. While prevention methods for leukemia are limited, avoiding risk factors like smoking and radiation exposure is advised. Leukemia can arise at any age, so awareness of potential symptoms is important. With modern treatments, even older adults with leukemia can have hope for remission and long term survival.