Leukemia Overview
Definition: A group of cancers affecting blood, bone marrow, lymphatic system,
and spleen, leading to the accumulation of dysfunctional cells due to deregulated
cell division.
Prevalence:
o
Affects all age groups.
o
~60,530 new cases diagnosed annually in the U.S.
o
Accounts for 28% of childhood cancers; 75% of these are lymphoid
leukemias.
Prognosis: Fatal if untreated, but advancements in treatment over the last 30
years have significantly improved outcomes.
Etiology and Pathophysiology
Causes:
o
Genetic mutations: Oncogenes triggered by DNA damage.
o
Environmental factors: Exposure to benzene, pesticides, radiation, and
smoking.
o
Viral associations: Human T-cell leukemia virus type 1 (HTLV-1).
o
Congenital conditions: Down syndrome, Klinefelter syndrome.
o
Chemotherapy: Prior exposure to alkylating agents or topoisomerase II
inhibitors.
Progression:
o
Bone marrow overcrowded by leukemic cells, reducing normal
hematopoiesis.
o
Abnormal white blood cells (WBCs) proliferate without normal apoptosis.
o
Infiltration into organs (e.g., spleen, liver) and tissues causes systemic
complications.
Classification of Leukemia
1. By Disease Progression:
o
Acute Leukemia: Rapid onset, involves immature cells (blasts). Includes
AML and ALL.
o
Chronic Leukemia: Gradual onset, involves mature but dysfunctional
cells. Includes CML and CLL.
2. By Affected Cell Type:
o
Myelogenous Leukemia: Involves myeloid cells.
o
Lymphocytic Leukemia: Involves lymphoid cells.
3. Overlap:
o
Some leukemias share features with lymphomas (e.g., lymphocytic
proliferation in NHL).
Types of Leukemia
Acute Myeloid Leukemia (AML)
Prevalence: ~80% of acute leukemias in adults; incidence increases after age
60.
Pathology: Uncontrolled proliferation of myeloblasts, hypercellular bone marrow.
Symptoms:
o
Abrupt onset: Fatigue, infections, bleeding, splenomegaly.
o
Gingival hyperplasia and headaches may occur.
Prognosis: Depends on age, genetic mutations, and treatment response.
Acute Lymphocytic Leukemia (ALL)
Prevalence: Most common childhood leukemia (75% of pediatric cases).
Pathology: Immature lymphocytes (primarily B-cells) proliferate in bone marrow.
Symptoms:
o
CNS involvement common: Headaches, increased intracranial pressure,
cranial nerve dysfunction.
o
Fever, pallor, fatigue, bone pain, hepatosplenomegaly.
Prognosis: Improved survival with aggressive treatment.
Chronic Myeloid Leukemia (CML)
Prevalence: Median age at diagnosis is 67; rare in children.
Pathology:
o
Excessive granulocyte proliferation in bone marrow.
o
Philadelphia chromosome (BCR-ABL gene fusion) is a diagnostic
hallmark.
Symptoms:
o
Early phase: Asymptomatic or mild fatigue.
o
Advanced phase: Splenomegaly, night sweats, weight loss, bone pain.
Prognosis: Controlled with tyrosine kinase inhibitors (e.g., imatinib); advanced
stages treated aggressively.
Chronic Lymphocytic Leukemia (CLL)
Prevalence: Most common leukemia in adults; median age of onset is 72.
Pathology: Accumulation of small, inactive lymphocytes (mainly B-cells).
Symptoms:
o
Often asymptomatic in early stages.
o
Advanced stages: Fatigue, lymphadenopathy, hepatosplenomegaly,
recurrent infections.
Prognosis: Slow progression; treatment depends on symptoms and patient age.
Clinical Manifestations
General Symptoms:
o
Fatigue, weakness, pallor, night sweats, fever.
o
Anemia: Reduced RBCs cause pallor and fatigue.
o
Thrombocytopenia: Increased bleeding risk (bruising, petechiae).
o
Leukopenia: Increased infection susceptibility.
Organ Infiltration:
o
Splenomegaly, hepatomegaly, lymphadenopathy.
o
CNS involvement: Increased intracranial pressure (especially in ALL).
o
Solid masses (chloromas): Rare localized collections of leukemic cells.
Complications:
o
Leukostasis: Blood thickening due to high WBC count (>100,000/μL),
causing circulatory blockages.
Diagnosis
Primary Tests:
o
Peripheral blood analysis.
o
Bone marrow biopsy (to identify leukemic cell types and mutations).
Advanced Diagnostics:
o
Cytogenetic studies: Philadelphia chromosome detection in CML.
o
Imaging (PET/CT scans): Detects extramedullary disease.
o
Lumbar puncture: Assesses CNS involvement (especially in ALL).
Treatment
Chemotherapy
1. Induction Therapy: Aggressive initial treatment to induce remission.
2. Consolidation Therapy: Eliminates residual leukemic cells.
3. Maintenance Therapy: Sustains remission, particularly in ALL.
Targeted Therapy
Tyrosine kinase inhibitors (e.g., imatinib for CML).
Monoclonal antibodies (e.g., rituximab for ALL/CLL).
Radiation Therapy
Used for organ-specific disease or CNS involvement.
Total body radiation as preparation for stem cell transplantation.
Hematopoietic Stem Cell Transplantation (HSCT)
Option for refractory or relapsed leukemia.
Risk of graft-versus-host disease (GVHD).
Emergent Treatments
Leukapheresis: Reduces WBC count in leukostasis.
Supportive care: Antibiotics, transfusions for anemia or thrombocytopenia.
Nursing Management
1. Acute Care:
o
Manage chemotherapy side effects: Neutropenia, anemia, and
thrombocytopenia.
o
Support psychological well-being of patients and families.
2. Long-Term Care:
o
Monitor for relapse, infections, and long-term effects.
o
Educate patients on self-care and the importance of follow-up.
3. Rehabilitation Goals:
o
Address delayed effects of treatment (e.g., peripheral neuropathy).
o
Connect patients to survivor support networks.
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