Leukemia

Overview

Leukemia is a cancer that begins in the bone marrow, the soft tissue inside bones where blood cells are made. In leukemia, the marrow produces large numbers of abnormal blood cells, most often abnormal white blood cells, that enter the bloodstream and crowd out healthy cells.

Leukemia frequency varies by type, but overall, it occurs more often in adults over 55, though it is also the most common cancer in children.

Leukemia is the second most common blood cancer after lymphoma and includes several distinct diseases.

The major types include:

Acute Lymphocytic Leukemia (ALL)

Chronic Lymphocytic Leukemia (CLL)

Acute Myeloid Leukemia (AML)

Chronic Myeloid Leukemia (CML)

Understanding How Leukemia Develops

Normally, the bone marrow produces:

White blood cells to fight infection
Red blood cells to carry oxygen
Platelets to help stop bleeding

In leukemia, a genetic change in an early blood‑forming cell leads to:

Uncontrolled growth of abnormal cells
Crowding out of normal red cells, white cells, and platelets
Poor functioning of blood and immune systems [medlineplus.gov]

Leukemias are classified by:

Speed of growth: acute (fast) vs. chronic (slow)
Cell type: lymphoid vs. myeloid

Signs & Symptoms

Symptoms depend on the leukemia type and how quickly it grows but may include:

Fatigue, weakness, or shortness of breath (from anemia)
Frequent infections (from low functioning white cells)
Easy bruising or bleeding, petechiae (from low platelets)
Fever or night sweats
Unexplained weight loss or appetite loss [oncodaily.com]
Enlarged lymph nodes, liver, or spleen
Bone pain

Chronic leukemias may cause no symptoms early on.

Risk Factors

Risk factors for leukemia put those in the following groups or with these ailments at an increased risk:

Older age

(especially over 60)

Caucasian Men

Exposure to high-dose radiation

Smoking

Certain Chemicals,

such as benzene

Past chemotherapy or radiation therapy

Certain inherited or genetic disorders

Family history of leukemia

How Leukemia is Diagnosed

Complete blood count (CBC)

to look for abnormal levels of white cells, red cells, or platelets

Peripheral blood smear

to inspect cell shapes

Bone marrow biopsy

to confirm leukemia type and assess blast percentage

Immunophenotyping (flow cytometry) and genetic testing

to determine the leukemia subtype, which guides treatment

Types of Leukemia

1. Acute Lymphocytic Leukemia (ALL)

Most common childhood cancer, but also occurs in adults
Defined by >5% blasts in bone marrow (untreated disease)
ALL is classified as untreated, in remission, or recurrent

2. Acute Myeloid Leukemia (AML)

Most common acute leukemia in adults
Often presents with fatigue, fever, infections, and bleeding
≥20% blasts in marrow defines AML
Also categorized as untreated, in remission, or recurrent

3. Chronic Lymphocytic Leukemia (CLL)

A slow‑growing leukemia common in older adults
May require watchful waiting until symptoms or progression occur

4. Chronic Myeloid Leukemia (CML)

A myeloproliferative leukemia caused by the Philadelphia chromosome (BCR‑ABL fusion)
Often diagnosed in adults; excellent outcomes with targeted therapy

Treatment Options

Treatment depends on leukemia type, genetic features, and overall health. Common treatment approaches include:

Standard for ALL and AML, and part of treatment for some chronic leukemias.

Includes agents that block specific mutations or proteins (e.g., BCR‑ABL inhibitors in CML). Targeted therapy is increasingly used across leukemia types.

Monoclonal antibodies, immune‑modulating therapies, and CAR T‑cell therapy (especially in some relapsed ALL and CLL).

Sometimes used in ALL, for symptom relief, or before a stem cell transplant.

Used in selected patients when high‑dose therapy is needed or in certain high‑risk disease situations.

Appropriate for some chronic leukemias, especially CLL without symptoms.

Supportive Care

Infection prevention

(vaccinations, prompt treatment of infections)

Transfusions

for anemia or low platelets, as needed

Management of treatment side effects

such as fatigue, nausea, neuropathy

Nutrition and activity guidance

throughout therapy

Prognosis

Prognosis varies widely by leukemia type and individual factors such as age, genetic features, and response to treatment.

Survival has improved significantly due to targeted therapies, better risk stratification, and supportive care advances.

ALL and CLL often have highly successful treatment outcomes, while AML and some aggressive leukemias may require more intensive therapy.

Follow-Up Care

After treatment begins, we create a personalized plan that may include:

Regular physical exams, labs, and bone marrow assessments

Monitoring of blood counts and treatment response

Long‑term surveillance for late effects of therapy

Coordination of supportive services such as nutrition, counseling, and survivorship programs

Why Choose Illinois CancerCare

A blood disorder diagnosis can feel overwhelming. At Illinois CancerCare, we are committed to ensuring you never have to face it alone. Providing advanced, comprehensive hematology and oncology care for our patients is at the heart of everything we do. Since 1977, our specialists have focused on individualized, evidence-based treatment plans, access to world-class clinical trials, and thorough follow-up. With Illinois CancerCare, you can move forward with confidence knowing trusted expertise and compassionate support are always close to home.‑based treatment plans, access to world‑class clinical trials, and thorough follow‑up.

Sources & Patient Friendly References

Information sourced from Mayo Clinic and NCI (National Cancer Institute).