Leukemia is a broad term for cancers affecting blood cells. This type of cancer targets the blood and bone marrow, leading to the overproduction of immature or abnormal white blood cells (leukocytes).
Blood Cell Basics
The blood comprises three main types of cells:
- White Blood Cells: Fight infection.
- Red Blood Cells: Carry oxygen.
- Platelets: Help blood clot.
Every day, the bone marrow produces billions of new blood cells, predominantly red cells. In leukemia, however, the body produces an excessive number of white blood cells that do not function properly. These abnormal cells interfere with the organs’ ability to work correctly, leading to a shortage of red blood cells, platelets, and normal white blood cells over time.
Symptoms and Demographics
Leukemia disrupts normal blood cell function, resulting in symptoms such as:
- Frequent bruising
- Bone pain
- Fatigue
- Weight loss
Leukemia is most common in adults older than 55 but is also the most prevalent cancer in children younger than 15.
Classification of Leukemia
Leukemia can be classified based on its onset and the type of cells affected:
Onset
- Acute Leukemia: Develops rapidly with immature blood cells.
- Chronic Leukemia: Develops more slowly with mature blood cells.
Cell Type
- Lymphocytic (or lymphoblastic) Leukemia: Involves bone marrow cells that become lymphocytes, a type of white blood cell.
- Myelogenous (or myeloid) Leukemia: Involves marrow cells that produce red blood cells, platelets, and other white blood cells.
Main Types of Leukemia
- Acute Lymphoblastic Leukemia (ALL)
- Acute Myeloid Leukemia (AML)
- Chronic Lymphocytic Leukemia (CLL)
- Chronic Myeloid Leukemia (CML)
Treatment Options
Treatment for leukemia in adults typically involves:
- Chemotherapy
- Radiation Therapy
- Stem Cell Transplantation
In recent years, targeted therapies have become part of the standard care for some leukemia types. These therapies focus on proteins that control cancer cell growth and spread. Newly approved targeted therapies for AML include:
- Enasidenib (Idhifa)
- Olutasidenib (Rezlidhia)
- Ivosidenib (Tibsovo)
- Venetoclax (Venclexta)
- Gemtuzumab ozogamicin (Mylotarg)
- Midostaurin (Rydapt)
- Gilteritinib (Xospata)
- Glasdegib (Daurismo)
- Quizartinib (Vanflyta)
Other advanced treatments include Bispecific T-cell engagers (BiTEs) like Blinatumomab (Blincyto), which has shown improved survival rates for ALL patients in remission after chemotherapy, and Menin inhibitors that block cancer-promoting genes.
Despite these advancements, survival rates vary among different leukemia types, and there is an ongoing need for less toxic treatment regimens, especially as the population ages.
Laboratory Tests for Leukemia
Accurate diagnosis, classification, and monitoring of leukemia rely on several laboratory tests:
Complete Blood Count (CBC)
- Measures levels of red blood cells, white blood cells, and platelets.
- Abnormal results often include high or low white blood cell counts, anemia, and thrombocytopenia.
Peripheral Blood Smear
- A drop of blood is spread on a slide, stained, and examined under a microscope to identify abnormal cells like blasts.
Bone Marrow Examination (Aspiration and Biopsy)
- Involves extracting and examining bone marrow samples to detect leukemia cells and assess cellularity and morphology.
Immunophenotyping
- Uses flow cytometry and immunohistochemistry to detect specific antigens on or within cells.
- Flow cytometry analyzes cell characteristics using lasers and fluorescently labeled antibodies.
- Immunohistochemistry identifies specific antigens in bone marrow or tissue samples.
Cytogenetic and Molecular Tests
- Karyotyping: Examines chromosomes for abnormalities like the Philadelphia chromosome in CML.
- Fluorescence In Situ Hybridization (FISH): Uses fluorescent probes to detect genetic abnormalities.
- Polymerase Chain Reaction (PCR): Amplifies DNA sequences to find genetic mutations or translocations.
- Next-Generation Sequencing (NGS): Provides a detailed genetic profile of leukemia cells to tailor treatment.
Molecular and Functional Tests
- Minimal Residual Disease (MRD) Testing: Detects residual leukemia cells post-treatment to predict relapse.
- Functional Assays: Evaluate leukemia cell functionality and sensitivity to treatments.
Supportive Laboratory Tests
- Biochemical Tests: Assess liver and kidney function, electrolyte balance, and lactate dehydrogenase (LDH) levels.
- Coagulation Studies: Evaluate blood clotting ability, as leukemia can cause bleeding disorders.
Advanced Imaging Techniques
- PET and CT Scans: Help assess disease spread and monitor treatment response.
Role of Laboratory Tests in Precision Medicine
Laboratory tests are crucial in precision medicine, guiding targeted therapies and personalized treatment plans. They allow for:
- Targeted Therapies: Identifying specific mutations for targeted drug use.
- Personalized Treatment: Tailoring treatment plans based on individual genetic profiles.
- Monitoring and Adjustments: Continuous monitoring ensures optimal therapy adjustments.
Understanding these aspects of leukemia, its diagnosis, and treatment options can provide valuable insights into managing this complex disease and improving patient outcomes.

Favour Olagookun
(Research Scientist)
Wow, great