Oncology & Hematological Disorders

Oncology and hematological nursing care encompasses the care of patients with cellular dysregulation, bone marrow suppression, antineoplastic pharmacology, and life-threatening oncologic emergencies.

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1. Oncology Fundamentals: Neoplasia & Staging

Malignancy is characterized by uncontrolled cellular proliferation, loss of contact inhibition, evasion of apoptosis, neo-angiogenesis, and the capacity for tissue invasion and distant metastasis.

• Benign Neoplasms: Well-differentiated cells resembling the parent tissue, encapsulated, slow localized growth, absence of invasive infiltration, and no distant metastasis.
• Malignant Neoplasms: Poorly differentiated or anaplastic cells, non-encapsulated, rapid infiltrative growth invading surrounding tissues, with high capacity for vascular and lymphatic metastasis.

The TNM Staging Classification

The American Joint Committee on Cancer (AJCC) TNM system standardizes the anatomical extent of disease:

• T (Primary Tumor Size & Extent):
  • TX: Primary tumor cannot be evaluated.
  • T0: No evidence of primary tumor.
  • Tis: Carcinoma in situ (confined to epithelium without basement membrane penetration).
  • T1, T2, T3, T4: Progressive increase in tumor size and local anatomical involvement.
• N (Regional Lymph Node Involvement):
  • NX: Regional lymph nodes cannot be evaluated.
  • N0: No regional lymph node metastasis.
  • N1, N2, N3: Progressive degree of regional lymph node involvement.
• M (Distant Metastasis):
  • M0: No distant metastasis detected.
  • M1: Distant metastasis confirmed.

The CAUTION Mnemonic for Cancer Detection

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2. Hematological Malignancies

The Leukemias

Leukemias are neoplastic proliferations of abnormal, immature white blood cell precursors that infiltrate bone marrow, crowding out normal hematopoiesis and causing pancytopenia (anemia, thrombocytopenia, and neutropenia):

• Acute Lymphoblastic Leukemia (ALL): Uncontrolled proliferation of immature lymphoblasts. Most common pediatric malignancy (peak incidence 2–5 years); highly responsive to chemotherapy with > 90% cure rate in children.
• Acute Myeloid Leukemia (AML): Proliferation of myeloblasts characterized by the histological presence of Auer rods (azurophilic cytoplasmic needle-like inclusions). Primarily affects older adults; causes rapid marrow failure.
• Chronic Lymphocytic Leukemia (CLL): Proliferation and accumulation of small, mature-appearing but immunologically incompetent B lymphocytes. Characterized by smudge cells on peripheral blood smear. Most common leukemia in older adults; indolent course.
• Chronic Myeloid Leukemia (CML): Myeloproliferative disorder marked by massive granulocytosis. Cytogenetically defined by the Philadelphia Chromosome, a reciprocal translocation between chromosomes 9 and 22, t(9;22)(q34;q11), which forms the chimeric BCR-ABL fusion oncogene encoding a constitutively active tyrosine kinase. Treated with targeted tyrosine kinase inhibitors (Imatinib / Gleevec).

The Lymphomas

• Hodgkin's Lymphoma: Malignancy of the lymphoid system characterized histologically by pathognomonic Reed-Sternberg cells (giant, multinucleated or bilobed B lymphocytes with prominent "owl-eye" nucleoli). Typically presents as painless, firm, rubbery, asymmetrical cervical or supraclavicular lymphadenopathy with orderly contiguous spread. Accompanied by "B Symptoms" (fever > 38°C, drenching night sweats, involuntary weight loss > 10% in 6 months) and alcohol-induced pain in diseased lymph nodes.
• Non-Hodgkin's Lymphoma (NHL): Heterogeneous group of B-cell or T-cell malignancies characterized by non-contiguous, diffuse lymph node involvement with early extranodal spread (GI tract, bone marrow, liver). Reed-Sternberg cells are absent; carries a poorer prognosis.

Multiple Myeloma

Neoplastic proliferation of malignant plasma cells in bone marrow producing excessive monoclonal immunoglobulins (M-protein spike on serum electrophoresis) and free light chains (Bence Jones proteinuria).

• Diagnostic CRAB Criteria:
  • C - Calcium Elevated (Hypercalcemia): > 11 mg/dL resulting from osteoclast activation; causes lethargy, polyuria, constipation, confusion.
  • R - Renal Insufficiency: Elevated serum creatinine (> 2 mg/dL) caused by toxic Bence Jones light-chain cast nephropathy obstructing renal tubules.
  • A - Anemia: Normocytic normochromic anemia caused by replacement of marrow hematopoietic tissue.
  • B - Bone Lesions: Multiple punched-out osteolytic bone lesions on skeletal radiographs; causes severe unremitting bone pain (especially back and ribs) and pathological fractures.
• Nursing Interventions: Vigorous IV hydration (3 to 4 L/day) to prevent light-chain tubular precipitation and treat hypercalcemia; gentle handling and ambulation assistance to prevent pathological fractures; pain management.

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3. Morphological Classification of Anemias

Anemia represents a reduction in total circulating red blood cell (RBC) mass, hemoglobin concentration, or hematocrit, classified morphologically by Mean Corpuscular Volume (MCV):

Microcytic Anemias

• Iron Deficiency Anemia: Most prevalent nutritional deficiency worldwide. Characterized by low serum ferritin (< 15 ng/mL, the most sensitive indicator of depleted stores), low serum iron, elevated Total Iron-Binding Capacity (TIBC), and decreased transferrin saturation.
  • Clinical Manifestations: Pallor, fatigue, glossitis (smooth, painful beefy-red tongue), angular cheilitis, koilonychia (brittle, concave "spoon-shaped" fingernails), and pica (craving non-nutritive substances: ice, dirt, starch).
  • Oral Iron Therapy (Ferrous Sulfate): Administer between meals or on an empty stomach with Vitamin C / orange juice, which maintains iron in the soluble ferrous state to enhance intestinal absorption. Avoid administering with milk, dairy products, tea, or antacids (calcium and tannins bind iron). Liquid iron must be taken through a straw and followed by mouth rinsing to prevent permanent enamel staining. Educate that stools will turn harmlessly dark green or black; manage constipation with fluids and dietary fiber.
• Thalassemia: Inherited hemoglobinopathy caused by defective alpha or beta globin chain synthesis. Thalassemia Major (Cooley's Anemia): Severe microcytic hemolytic anemia presenting in infancy with hepatosplenomegaly, jaundice, and bone marrow expansion resulting in "chipmunk facies" and frontal bossing. Requires lifelong blood transfusions, which induce hemosiderosis (systemic iron overload); managed with iron chelation therapy (deferoxamine or deferasirox).

Macrocytic / Megaloblastic Anemias

• Vitamin B12 (Cobalamin) Deficiency & Pernicious Anemia: Pernicious anemia is an autoimmune disorder with autoantibodies directed against gastric parietal cells or intrinsic factor. Intrinsic factor is mandatory for B12 absorption in the terminal ileum. Diagnosed historically via the Schilling test.
  • Clinical Manifestations: Megaloblastic anemia, lemon-yellow skin pallor, smooth "beefy-red" tongue, alongside NEUROLOGICAL MANIFESTATIONS THAT CAN BECOME IRREVERSIBLE IF TREATMENT IS DELAYED: Paresthesias of hands and feet, loss of vibratory sensation and proprioception, ataxia, spasticity, and dementia (subacute combined degeneration of the spinal cord).
  • Treatment: Lifelong monthly intramuscular injections of Cyanocobalamin (Vitamin B12 1000 mcg). Standard oral doses are poorly absorbed without intrinsic factor, so parenteral therapy is the classic answer (very high oral doses can work in some patients through passive diffusion of about 1%).
• Folic Acid Deficiency: Caused by inadequate dietary intake (malnutrition, chronic alcoholism) or increased physiological demand (pregnancy). Produces megaloblastic anemia and glossitis identical to B12 deficiency, but WITHOUT neurological deficits. Co-administering folate alone in an individual with undiagnosed B12 deficiency resolves the anemia while permitting permanent, catastrophic neurological damage to proceed.

Normocytic Anemias & Sickle Cell Disease

• Aplastic Anemia: Bone marrow hypoplasia or aplasia resulting in profound pancytopenia. Confirmed by bone marrow biopsy demonstrating hypocellularity with fatty infiltration. High risk of fatal infection and spontaneous hemorrhage.
• Sickle Cell Anemia: Autosomal recessive disorder caused by a point mutation in the beta-globin gene substituting valine for glutamic acid at position 6, creating Hemoglobin S (HbS). Under deoxygenated conditions (hypoxemia, dehydration, acidosis, cold exposure), HbS polymerizes into rigid filaments, distorting RBCs into fragile, crescent-shaped "sickle" cells that cause microvascular occlusion and hemolytic destruction.
  • Sickle Cell Crises: Vaso-occlusive Crisis (Painful Crisis): Microvascular occlusion causing acute, severe ischemic bone, joint, and abdominal pain. Acute Chest Syndrome: Pulmonary microvascular sickling presenting with fever, chest pain, tachypnea, cough, hypoxemia, and new infiltrates; the leading cause of mortality. Splenic Sequestration: Rapid entrapment of RBCs in the spleen, precipitating life-threatening hypovolemic shock in young children.
  • Emergency Nursing Protocol ("HOP"): H - Hydration: Aggressive IV fluids (1.5–2 times maintenance) to decrease blood viscosity and reverse microvascular sludging. O - Oxygenation: Supplemental oxygen to treat hypoxemia and prevent further sickling. P - Pain Relief: Scheduled continuous IV opioids (morphine, hydromorphone); avoid meperidine (Demerol) due to metabolite normeperidine neurotoxicity and seizures. Disease-modifying agent: Hydroxyurea (stimulates fetal hemoglobin HbF production, reducing sickling frequency).

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4. Chemotherapy Safety & Extravasation Care

Antineoplastic agents are cytostatic drugs categorized by mechanism of action:

• Alkylating Agents (Cyclophosphamide): Cross-link DNA. Primary toxicity is hemorrhagic cystitis. Prevented by aggressive oral/IV hydration and administration of MESNA (a sulfhydryl compound that detoxifies urotoxic acrolein metabolites).
• Antitumor Antibiotics (Doxorubicin / Adriamycin): Intercalates DNA. Known as the "red devil"; carries a dose-limiting cumulative cardiotoxicity (lifetime dose limited to < 550 mg/m² to prevent congestive heart failure); causes harmless red discoloration of urine.
• Mitotic Inhibitors (Vincristine): Inhibits microtubule assembly. Causes dose-limiting peripheral neuropathy and paralytic ileus. CRITICAL SAFETY WARNING: Fatal if administered intrathecally; vincristine must ONLY be given intravenously.
• Antimetabolites (Methotrexate): Inhibits dihydrofolate reductase. Causes severe stomatitis and bone marrow suppression; rescued by Leucovorin (folinic acid).

Hazardous Drug Handling Precautions (ONS / OSHA Standards)

• Prepare chemotherapy drugs inside a Class II or III Biological Safety Cabinet (BSC).
• Personal Protective Equipment (PPE): Wear specialized chemotherapy-tested powder-free nitrile gloves (double gloving: inner glove under the gown cuff, outer glove over the cuff; change gloves every 30 minutes). Wear a disposable, lint-free, non-permeable gown with closed front and tight cuffs. Use eye goggles or a face shield if splash risk exists.
• Dispose of all contaminated tubing, needles, and bags in dedicated puncture-resistant yellow chemotherapy waste containers.

Management of Chemotherapy Extravasation

Extravasation is the accidental leakage of a vesicant antineoplastic agent into perivascular subcutaneous tissue, causing severe blistering, sloughing, and necrosis.

• Vesicants: Doxorubicin, epirubicin, vincristine, vinblastine, cisplatin.
• Immediate Step-by-Step Nursing Protocol:
  1. Immediately STOP the infusion upon the first sign of pain, burning, swelling, or loss of blood return.
  2. Do NOT remove the IV catheter immediately. Disconnect the IV tubing, attach a syringe, and gently aspirate as much residual drug and blood as possible from the cannula lumen.
  3. Administer drug-specific antidote if ordered through the catheter before removal.
  4. Remove the catheter and avoid applying manual pressure to the site.
  5. Thermal Management (Drug-Specific):
     • Apply DRY COLD COMPRESSES for DNA-binding agents (Anthracyclines / Doxorubicin, Alkylating agents) to induce vasoconstriction, limiting local drug spread.
     • Apply DRY WARM COMPRESSES for non-DNA binding agents (Vinca Alkaloids / Vincristine) to induce local vasodilation, enhancing systemic drug dispersal and absorption.
  6. Elevate the affected extremity for 48 hours to minimize edema; notify the oncologist, document the event, and monitor for ulceration.

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5. Oncologic Emergencies

Neutropenic Fever (Neutropenic Sepsis)

• Absolute Neutrophil Count (ANC) Calculation: $\text{ANC} = \text{Total WBC} \times \frac{\% \text{Segmented Neutrophils} + \% \text{Band Forms}}{100}$
• Severe Neutropenia: ANC < 500/μL.
• Definition of Neutropenic Fever: Single oral temperature ≥ 38.3°C (101°F), or sustained temperature ≥ 38.0°C (100.4°F) for ≥ 1 hour in a neutropenic patient.
• Emergency Action: Neutropenic patients cannot mount an inflammatory response (erythema and pus are absent). Sepsis can prove fatal within hours. Obtain blood cultures immediately and administer broad-spectrum IV antibiotics within 60 minutes ("The Golden Hour").
• Protective Isolation Precautions: Admit to a private room (positive pressure airflow preferred); strict hand hygiene; eliminate fresh flowers, plants, and standing water; prohibit raw unpeeled fruits, raw vegetables, and undercooked meats; avoid invasive procedures (no rectal temperatures, enemas, suppositories, or urinary catheterizations) to prevent mucosal trauma.

Thrombocytopenia

Platelet count < 150,000/μL.

• Platelets < 50,000/μL: Initiate Bleeding Precautions (use soft-bristled toothbrush or foam swabs, electric razors only, avoid aspirin/NSAIDs, avoid IM/subcutaneous injections, apply pressure for 5–10 minutes post-venipuncture, prevent falls).
• Platelets < 20,000/μL: High risk for spontaneous, life-threatening hemorrhage (intracranial hemorrhage, massive GI bleeding). Transfuse platelets immediately as ordered.

Tumor Lysis Syndrome (TLS)

Massive, rapid destruction of malignant cells following induction chemotherapy for high-grade hematological malignancies (ALL, Burkitt's lymphoma), releasing massive intracellular contents into the systemic circulation:

1. Hyperkalemia (> 5.0 mEq/L): Cellular potassium release causes lethal cardiac dysrhythmias and arrest.
2. Hyperphosphatemia (> 4.5 mg/dL): Cellular nucleic acid release elevates phosphate, which binds serum calcium, forming insoluble calcium phosphate crystals in renal tubules.
3. Hypocalcemia (< 8.5 mg/dL): Secondary to phosphate binding; causes tetany, positive Chvostek's / Trousseau's signs, paresthesias, and seizures.
4. Hyperuricemia (> 8.0 mg/dL): Purine catabolism yields uric acid, which crystallizes in acidic renal collecting ducts, causing acute oliguric renal failure.

• Prevention & Management: Aggressive IV hydration (2–3 L/m²/day) initiated 24–48 hours prior to chemotherapy; administration of Allopurinol (xanthine oxidase inhibitor preventing new uric acid formation) or Rasburicase (recombinant urate oxidase converting insoluble uric acid into soluble allantoin); continuous cardiac monitoring; hemodialysis if refractory.

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6. Radiation Therapy Safety & Care

• External Beam Radiation (Teletherapy): Patient is NOT radioactive. Skin care instructions: Cleanse irradiated skin gently with lukewarm water and mild soap; pat dry with soft towel; do not wash off radiation ink tattoos; avoid applying lotions, ointments, perfumes, or powders to the treatment field unless approved by the radiation team; protect skin from sun exposure and temperature extremes (no heating pads or ice packs); wear loose, soft cotton clothing.
• Internal Radiation (Brachytherapy): Radioactive source placed inside or adjacent to tumor. The patient emits radiation and is a potential hazard to others.
• The ALARA Principle (As Low As Reasonably Achievable):
  1. Time: Minimize direct contact time (maximum 30 minutes of bedside nursing care per 8-hour shift).
  2. Distance: Maximize physical distance; maintain a minimum distance of 6 feet (2 meters) from the radiation source whenever not delivering direct hands-on care.
  3. Shielding: Wear a protective lead apron during care; place the patient in a private room with lead-shielded walls; display "Caution: Radiation Material" signage on the door.
  • Personal Dosimeter Film Badge: Must be worn by nursing personnel at all times to monitor cumulative personal exposure (never share badges; do not wear outside the hospital).
  • Restrictions: Pregnant staff and visitors, as well as children under 18 years of age, are strictly prohibited from entering the patient's room.
  • Emergency Protocol for Dislodged Source: Never touch a dislodged radioactive implant directly with bare hands. Use long-handled lead forceps to pick up the dislodged source immediately, place it inside the bedside lead container ("lead pig"), and immediately contact the Radiation Safety Officer and radiation oncologist.