Leukemia

Key Terms to Know

• "Acute" vs "Chronic": Acute = rapid onset and progression; Chronic = slower progression (though still serious).
• Philadelphia chromosome: An abnormal chromosome found in CML; predicts excellent response to targeted therapy.
• Tyrosine kinase inhibitors (TKIs): Targeted drugs like imatinib (Gleevec) that block specific cancer signals; standard for CML.
• Cytochemistry/Cytogenetics: Lab tests that classify leukemia cells and identify mutations.
• Complete remission: Cancer is undetectable, but doesn't mean cured; continued monitoring essential.

Risk Factors

• Age: Some types (AML, CLL) more common in older adults; ALL more common in children.
• Genetic conditions: Down syndrome, Li-Fraumeni syndrome increase risk.
• Radiation exposure: Previous cancer treatment or occupational exposure.
• Chemical exposure: Benzene (solvent in industry).
• Previous chemotherapy: Secondary leukemia risk after other cancer treatment.
• Family history: Rare familial clustering.

Symptoms and Diagnosis

Symptoms (can overlap with many conditions):

• Fatigue and weakness (from anemia)
• Frequent infections (from low white blood cells)
• Easy bruising or bleeding (from low platelets)
• Bone or joint pain
• Enlarged lymph nodes, spleen, or liver
• Night sweats or fevers

These symptoms can be caused by many conditions. Blood tests are needed for diagnosis.

Diagnosis involves:

• Complete blood count (CBC): Counts different blood cell types.
• Peripheral blood smear: Microscopic examination of blood cells.
• Bone marrow biopsy: Sample of marrow examined for cancer cells.
• Cytogenetics and molecular testing: Identifies specific mutations (e.g., Philadelphia chromosome in CML).

Treatment Options

Chemotherapy

Standard treatment for acute leukemias (ALL, AML):

• Intensive induction chemotherapy aims for complete remission (undetectable cancer).
• Consolidation therapy follows remission to prevent relapse.
• Side effects can be significant but manageable with support care.

Targeted Therapy

For specific mutations:

• Tyrosine kinase inhibitors (TKIs) for CML: Imatinib (Gleevec), dasatinib, nilotinib. Often taken as oral daily pills; dramatically improved CML survival.
• FLT3 inhibitors, IDH inhibitors, BCL2 inhibitors: For specific AML subtypes with mutations.

Stem Cell Transplant (Bone Marrow/Hematopoietic Stem Cell Transplant)

Used for high-risk or relapsed leukemias:

• Replaces patient's diseased marrow with healthy donor cells (allogeneic transplant) or reinfuses patient's own previously harvested cells (autologous transplant).
• Intensive procedure with significant risks and benefits; candidacy depends on age, fitness, disease risk.

Immunotherapy

CAR-T cell therapy: Engineered immune cells targeting leukemia; FDA-approved for relapsed/refractory ALL in children and young adults.

Supportive Care

Critical for all leukemia patients:

• Blood transfusions (platelets and red blood cells)
• Antibiotics for infection prevention/treatment
• Growth factors to boost white blood cell production
• Pain and symptom management

Common Side Effects and Management

• Chemotherapy-induced nausea/vomiting: Anti-nausea medications are highly effective.
• Hair loss: Temporary; hair regrows after treatment ends.
• Infections: White blood cell counts drop; prophylactic antibiotics may be used.
• Bleeding/bruising: Platelet transfusions prevent serious bleeds.
• Mouth sores (mucositis): Pain management, special mouthwashes help.
• Fatigue: Common during and after treatment; activity pacing helps.
• Fertility impacts: Chemotherapy can affect fertility; discuss fertility preservation before treatment.