Leukemia is a type of cancer impacting the blood or bone marrow, which is responsible for the generation of blood cells. It predominantly disrupts the production of leukocytes, or white blood cells.
Predominantly affecting individuals over the age of 55, leukemia is, however, the most prevalent form of cancer among those under 15 years of age.
According to the National Cancer Institute, it is projected that in the United States, there will be around 60,650 new cases of leukemia in 2022, with an expected 24,000 fatalities resulting from the disease within the same timeframe.
Leukemia manifests in various forms, and the prognosis is contingent on the specific type. While acute leukemia progresses swiftly and deteriorates rapidly, chronic leukemia gradually worsens over time.
This article offers a comprehensive look at leukemia, encompassing its causes, treatment options, various types, and symptoms.
Causes
Leukemia arises when the DNA of maturing blood cells, predominantly affecting white blood cells, undergoes damage. This leads to uncontrolled growth and division of these cells.
Typically, healthy blood cells have a lifecycle that culminates in death, after which new cells form within the bone marrow to replace them.
In the case of leukemia, however, these blood cells proliferate too rapidly and do not operate correctly. These cells also fail to expire as they naturally should, leading to an accumulation that monopolizes space within the blood.
As the bone marrow continues to churn out these cancerous cells, they start to outnumber and inhibit the growth and function of healthy white blood cells. This imbalance also influences red blood cells and platelets.
Over time, the malignant cells become more prevalent than the healthy cells in the bloodstream.
Risk considerations
The exact cause of leukemia is often undetermined, but experts believe that a combination of environmental and genetic factors may contribute.
Genetic predispositions may not directly cause leukemia, but can increase susceptibility to the disease when coupled with certain conditions or exposures to particular substances or infections.
The contributing risk factors vary depending on the type of leukemia. Some of these factors can be avoided, but not all.
Research has indicated potential correlations between leukemia and a range of factors, but further studies are needed to establish these connections definitively.
These factors can include:
- A history of specific infections like Epstein-Barr virus
- Exposure to ionizing radiation, which could occur through radiation treatments for previous cancers, environmental radiation exposure, or proximity to nuclear testing sites
- Having been born with either a particularly low or high birth weight
- Being male, since leukemia incidence is higher among males
- Contact with agricultural chemicals and urban air pollution
- Secondhand smoke exposure from parental smoking habits
- Being born through cesarean delivery before the onset of labor
- Possessing genetic syndromes such as Down syndrome or Klinefelter syndrome
- Contact with the chemical benzene
- A history of undergoing chemotherapy treatments
- A prior experience with another type of blood cancer
Types
Doctors classify the different types of leukemia according to:
the type of blood cell they start in
whether they are acute (grow quickly) or chronic (grow slowly)
if they occur in a child or an adult
Categories of Leukemia: Acute and Chronic
In acute leukemia, there’s a rapid proliferation of immature blood cells known as blasts that accumulate in the bone marrow and bloodstream. A diagnostic blood test typically reveals that blasts constitute more than 20% of the blood cells, indicating they are prematurely released and non-functional.
Conversely, chronic leukemia progresses at a slower rate and produces more mature and functional cells. In this condition, a blood test usually shows less than 20% of blasts.
Varieties of Leukemia: Lymphocytic and Myelogenous
Lymphocytic leukemia arises when the transformation into cancer occurs in the bone marrow cells responsible for generating lymphocytes, a type of white blood cell integral to the immune system.
Myelogenous leukemia, on the other hand, concerns alterations in the bone marrow cells tasked with producing blood cells, rather than the blood cells themselves.
Common Leukemia Forms
Several forms of leukemia exist, including:
Acute Lymphocytic Leukemia
Predominantly seen in children under 5 years, acute lymphoblastic leukemia (ALL) can also manifest in adults, usually those over 50 years old. About 60% of leukemia cases in children are ALL.
For further information on ALL, follow this link.
Chronic Lymphocytic Leukemia
Mainly appearing in individuals older than 70, chronic lymphocytic leukemia (CLL) can also occur in younger adults. CLL represents about 25% of new leukemia diagnoses, is more prevalent in males, and is uncommon in children.
For more details on CLL, visit this page.
Acute Myelogenous Leukemia
Acute myelogenous leukemia (AML) is more frequently diagnosed in adults than in children and is more common in males. AML is overall a rare condition.
More about AML can be found here.
Chronic Myeloid Leukemia
Making up about 15% of leukemia cases in the U.S., chronic myelogenous leukemia (CML) is seldom seen in children.
For additional information on CML, click here.
Hairy Cell Leukemia
This infrequent type of leukemia, hairy cell leukemia (HCL), typically affects middle-aged and older adults, with approximately 1,000 new cases annually in the U.S. HCL is chronic and slow-growing, earning its name from the hair-like projections visible on the cancer cells under a microscope.
Treatment
The approach to managing leukemia varies based on several factors:
- Tumor classification
- Patient age
- General health state
Healthcare providers may propose several treatment strategiesTrusted Source, such as:
- Monitoring without immediate action for indolent leukemias, like CLL and HCL
- Chemotherapeutic treatments
- Radiotherapy
- Precision medicine targeting specific cancer characteristics
- Biological therapy to bolster immune response
- Hematopoietic stem cell transplantation
- Surgical spleen removal if necessary
- Combined stem cell and chemotherapy interventions
Each treatment plan is customized for the leukemia type. Early commencement of treatment typically enhances success rates.
Symptoms
Symptoms of leukemia vary according to the type.
They include the following:
Propensity for Bruising or Hemorrhaging
Leukemia impairs clotting by interfering with platelets, essential for blood coagulation.
Indications can include:
- Frequent, effortless bruising
- Prolonged bleeding from minor injuries
- Regular nosebleeds or gum bleeding
- Emergence of petechiae – small, pinpoint red skin marks
- Formation of purpura – larger purple skin areas
Increased Infection Risk
White blood cells serve as the infection defense mechanism. When they malfunction, frequent infections may arise. The compromised immune system might mistakenly target healthy cells.
Anemic Conditions
Insufficient functional red blood cells lead to anemia, characterized by a lack of ample hemoglobin.
Anemia’s symptoms may consist of:
- Feeling faint or experiencing vertigo
- General weakness
- Persistent fatigue
- Breathing difficulties
- Accelerated heart rate
- Muscle or body soreness
- A pale complexion
Additional Manifestations
Other potential symptoms may encompass:
- Nausea
- Elevated body temperature
- Bone discomfort
- Loss of weight
Leukemia’s symptoms are not exclusive to the condition and can overlap with other health issues. Concerns about symptoms should prompt a consultation with a healthcare provider, who will conduct necessary examinations to ascertain the cause.
For more information on leukemia’s symptoms, including early signs and presentation in children, please refer to this resource.
Diagnosis
To diagnose leukemia, a medical professional will generally:
- Complete a thorough physical examination
- Inquire about the individual’s and their family’s health history
- Look for indications of anemia
- Check for any enlargement of the liver or spleen
- Obtain a blood sample for lab analysisTrusted Source
Should leukemia be suspected, the healthcare provider may recommend a bone marrow biopsy. This procedure involves extracting bone marrow from the center of a bone, often the hip bone, with a specialized needle.
The biopsy helps determine the presence and category of leukemia affecting the patient.
Frequently asked questions
What causes leukemia to develop?
Leukemia’s development may be influenced by genetic and environmental factors. Various forms of leukemia might be linkedTrusted Source to exposure to radiation and certain chemicals, such as tobacco smoke and benzene, or other pre-existing health issues.
How grave is leukemia?
All forms of cancer, including leukemia, require medical intervention. Leukemia exhibits diverse types and growth rates. Untreated, leukemia can be life-threatening. However, advances in medicine now offer better survival prospects than before.
What are the chances of surviving leukemia?
The overall five-year survival rate for individuals with leukemia is about 65.7%Trusted Source, based on data from 2012–2018. For children, this rate is nearly 86%Trusted Source. Survival rates significantly diverge by leukemia type. For instance, the five-year survival is about 90%Trusted Source for children with ALL.
Summary
Leukemia is a cancer that targets the blood and bone marrow. It presents in multiple forms, with some predominantly affecting children.
The precise causes of leukemia remain unclear, although it is believed that genetics and certain environmental exposures, including to pesticides and other toxins, might contribute.
Chemotherapy is the primary treatment for leukemia, with supplementary methods varying based on the leukemia type.
Survival rates for those diagnosed with leukemia have substantially improved over the years.
