Cancer is a disease caused by the abnormal growth and division of cells in the body. It is a complex illness that can have fatal consequences when the body’s sustenance is compromised. Leukemia, a type of cancer, is known for its ability to infiltrate blood cells from the bone marrow. It can be classified based on the lineage of bone marrow cells it affects or the growth rate. Let’s know more about the types:

1. Acute lymphocytic/lymphoblastic leukemia (ALL)
This is the most common type of leukemia, which is more prevalent in young kids than adults. It is characterized by the hyperproduction of abnormal lymphocytes from the blood stem cells in the bone marrow, affecting other granulocytic immune cells. A healthy lymphocyte further proliferates into:

• B cells – produce antibodies
• T cells – i ndulge in cell-mediated immunity and secrete B cell activators
• Natural killer cells – fight against cancer and virus

However, the immature lymphocytes are not capable of effectively fighting off infections. It also causes anemia due to decreased RBC production and a clotting disorder due to insufficient platelet production. It may also spread to the Central Nervous System (brain and spine), spleen, liver, and lymph nodes. Exposure to radiation or chemotherapy in the past increases the chance of recurrence of ALL.

2. Acute myeloid leukemia (AML)
Acute myeloid leukemia type is most common in adults and attacks the myeloid lineage cells arising from the bone marrow. Under healthy conditions, they differentiate into:

• Red blood cells
• Platelets
• White blood cells – Basophil, neutrophil, eosinophil, mast cell, and monocytes.

AML suppresses the production of healthy blood cells, impairing the body’s ability to combat infections, control bleeding, and transport oxygen. Men and people with blood-related genetic disorders like trisomy eight and Wescott-Aldrich syndrome are more prone to AML.

3. Chronic lymphocytic leukemia (CLL)
Chronic lymphocytic leukemia is a slow-growing cancer arising from the bone marrow and invades the liver, spleen, and lymph nodes. It is like ALL and only differs because symptoms take longer due to the slow proliferation of immature lymphocytes. CLL may not require aggressive treatment like acute leukemias, but its progression should be monitored.

4. Chronic myeloid leukemia (CML)
Mature granulocytes that arise from myeloid progenitors are:

• Basophil: Allergy and other activities
• Eosinophil: against parasites and allergies
• Neutrophil: against bacteria and fungus

CML is a slow-growing type of myelogenous leukemia with a particular peak in the level of basophils. Sometimes, this condition may turn acute, hastening the progression, which may prove difficult to treat.
The symptoms and complications associated with the leukemia types are similar:

• Anemia: decreased hemoglobin
• Pancytopenia: overall decrease in RBC, WBC and platelets
• Thrombocytopenia: decrease in platelets
• Fatigue
• Susceptibility to frequent viral and bacterial infections

Diagnosis for all types of leukemia involves CBC (complete blood count) to study the number of lymphocytes and RBC with varying parameters. Bone marrow aspiration followed by biopsy is the most accurate way of detecting leukemia. Genetic testing may also be performed if the condition is suspected to be linked to a mutated chromosome.

The treatment varies from individual to combined stem cell therapy, commonly known as bone marrow transplant, chemotherapy, radiation therapy, and targeted therapy using monoclonal antibodies. This makes it possible to treat patients with a high success rate.