ALL

What it is

Overview

Acute Lymphoblastic Leukemia (ALL) is the most common cancer in children, making up ~25% of all childhood cancers. It is a cancer of the blood and bone marrow that begins in immature lymphocytes (a type of white blood cell). With modern treatment, childhood ALL has a cure rate of approximately 90% — one of the great success stories of pediatric oncology.

Biology

How It Develops

ALL begins when a single lymphoid progenitor cell acquires genetic mutations (often chromosomal rearrangements like the ETV6-RUNX1 fusion) that block normal maturation. This cell then proliferates rapidly, overwhelming the bone marrow and crowding out normal blood cell production, leading to anemia, infection susceptibility, and bleeding.

Warning signs

Symptoms

• —Fatigue, pallor, and weakness (anemia)
• —Frequent infections (low white blood cells)
• —Easy bruising or bleeding (low platelets)
• —Bone or joint pain
• —Swollen lymph nodes, liver, or spleen
• —Fever without obvious cause

Detection

Diagnosis Methods

• —Complete blood count (CBC) with differential
• —Bone marrow biopsy and aspiration
• —Flow cytometry (immunophenotyping)
• —Cytogenetics and FISH for chromosomal abnormalities
• —Lumbar puncture (CNS involvement assessment)
• —MRD (minimal residual disease) testing

Medical care

Treatment Options

• —Multi-agent induction chemotherapy (vincristine, prednisone, asparaginase)
• —CNS-directed therapy (intrathecal chemo)
• —Consolidation and maintenance phases (2–3 years total)
• —Targeted therapy (tyrosine kinase inhibitors for Ph+ ALL)
• —CAR-T cell therapy (tisagenlecleucel for relapsed/refractory)
• —Stem cell transplant for high-risk relapsed disease

Data

Statistics

Prevention

Risk Factors

• —Down syndrome
• —Certain inherited genetic conditions
• —Prior radiation exposure
• —Certain infections (Epstein-Barr virus in some cases)
• —Unknown factors (most cases have no clear cause)

Further reading

Resources