ONCOLOGY

Core Concepts of Cellular Regulation

  • Cell Growth Fundamentals: Cells grow in an orderly manner to allow body development from the initial stages to maturity.

  • Homeostasis Maintenance: To maintain homeostasis, old cells must be replaced by new cells through a strict process known as cellular regulation.

  • Cellular Regulation Defined: During this process, genes interact to control cell growth, replication, and differentiation.

  • Mechanisms of Growth: Through the processes of promotion and suppression, cells continue to grow and mature until they are no longer needed.

  • Key Requirement: Normal cell growth must be orderly and must follow strict cellular regulation.     * Formula for Normal Balance: Orderly+Strictly Promotion=Suppression\text{Orderly} + \text{Strictly Promotion} = \text{Suppression}.

  • Normal Cell Characteristics: Normal cells possess specific characteristics that ensure optimal physiological function.

Characterization of Neoplasms

  • Neoplasia and Neoplasms: A breakdown in the internal cell promotion and suppression processes causes problems with cellular regulation, leading to abnormal cells called neoplasia or neoplasms.

  • Neoplasm Definition: An abnormal cell growth or abnormal cell function. Neoplastic cells do not function normally and have characteristics that differ from normal cells.

  • Categories of Neoplasms:     * Benign: Non-cancerous and not generally harmful. Growth is continuous and inappropriate; they expand but remain contained. These cells still contain normal genes.     * Malignant: Cancerous and harmful in terms of toxic effects on the body. They grow rapidly, expand, and are invasive (invading surrounding tissues). These cells possess defective or mutated genes.

Classification and Staging of Cancer

  • Classification Criteria: Cancers are classified by several factors:     * Tissue type.     * Biological behavior.     * Anatomic site.     * Degree of differentiation.

  • Diagnostic Tools: Grading and staging are used to:     * Confirm the diagnosis.     * Determine the prognosis.     * Inform treatment decisions.

Etiology: Causes of Carcinogenesis

  • Carcinogenesis (Oncogenesis): Defined as cancer development. This process takes years to occur and is dependent on three interacting factors:     1. Exposure to a carcinogen.     2. Genetic disposition.     3. Immunity.

  • Susceptibility: Not all cells are susceptible to carcinogenesis.

  • External Factors (Exposures):     * Chemical: Includes tobacco, alcohol, drugs, and products used in everyday life. Some substances act as co-carcinogens.     * Physical: Includes radiation and chronic irritation (e.g., Gastritis or GERD, which exposes the esophagus to stomach acids).     * Viral (Oncoviruses): Includes Human Papillomavirus (HPV), Hepatitis B Virus (HBV), and Epstein-Barr Virus (EBV).     * Bacterial: Includes H. pylori, Salmonella, and Chlamydia.

  • Personal Factors:     * Immunity: Reduced immunity, often seen in advancing age, organ transplant recipients, and individuals with AIDS.     * Genetic Disposition: Referred to Chart 12−112-1 (Genetics in Nursing Practice, p. 267267) for individual risk.     * Hormonal Changes: Related to the body’s own production of hormones or from taking hormonal therapy.     * Lifestyle Factors: Includes smoking, poor diet, and physical inactivity.

Stages of Cancer Development

  • Initiation and Promotion Stage:     * Carcinogens alter the genetic activity of a cell, enabling it to become a cancer cell.     * Promoter substances enhance the growth of the initiated cell to form a tumor.     * Cellular regulation is lost, which promotes excessive cell division.

  • Progression Stage:     * The cancerous tumor secretes vascular growth factors to stimulate the formation of a new blood supply within the tumor (Tumor Vascularization).     * Tumor cells continue to proliferate and form distinct clusters to sustain themselves.

  • Metastatic Stage:     * Involves blood vessel penetration and invasion.     * Cancer cells break away from the primary tumor, enter the blood vessels, and invade other areas to become a secondary cancer or a metastatic tumor.

Cancer Prevention

  • Primary Prevention: Strategies focusing on preventing the actual occurrence of cancer.     * Avoidance of known carcinogens (e.g., smoking affects the lungs and urothelium/bladder lining).     * Modifying associated factors (e.g., diet).     * Removal of at-risk tissues (e.g., polyps).     * Chemoprevention (e.g., using drugs to prevent conditions that lead to cancer).     * Vaccination (e.g., HPV).

  • Secondary Prevention: Strategies focusing on screening for early detection.     * Prostate screenings.     * Colonoscopy.     * Digital Rectal Examinations (DREs).     * Annual mammography.

Principles of Cancer Therapy

  • Treatment Types: Surgery, biologic materials, chemicals, and gamma rays.

  • Approach: Therapies can be used separately or in combination. The option depends on the cancer type, stage, and the patient’s overall function.

  • Multimodal Approach: Combining chemotherapy and radiation, surgery and radiation, or surgery and chemotherapy. This is the most effective way to eliminate what was not removed by a single therapy.

  • Impact on Normal Cells: Cancer therapies affect normal cells and organ function. Normal cells that divide rapidly are the most susceptible, including those lining the stomach, hair follicles, and bone marrow.

Radiation Therapy (Radiotherapy)

  • Definition: Uses high-energy radiation from gamma rays, radionuclides, or ionizing isotopes to kill cancer cells, slow growth, or control symptoms.

  • Dosing: Often given in divided doses because cancer cells have varying responses; some die after one dose, while others require several.

  • External Beam Therapy (Teletherapy):     * Local treatment delivered from outside the patient (also called block out).     * Only the tissues in the direct path of the rays are affected (e.g., skin on the neck for a neck tumor).     * Skin markings are used to ensure precision; patients must be taught not to remove these markings.     * The patient is not radioactive or a hazard to others.

  • Internal Radiation (Brachytherapy):     * Systemic/internal treatment where radioactive isotopes are placed inside the body in continuous contact with the tumor for a specified time.     * Overall, the patient is radioactive and a hazard to others.     * Sealed Implants (Solid Form): Body waste and fluids are not radioactive.     * Unsealed Isotopes: Body waste and fluids are radioactive.

Chemotherapy (Cytotoxic Systemic Therapy)

  • Mechanism: Uses chemical agents to kill cancer cells by damaging DNA and interfering with cellular division.

  • Efficacy: Most effective on tumors with rapid growth.

  • Susceptible Normal Cells: Affects rapidly dividing cells including skin, hair, intestines, sperm, and blood-forming cells.

  • Administration: Given regularly to maximize effect while allowing normal cells to recover.

  • Routes:     * IV Chemotherapy: Administered in hospitals/clinics by oncology-certified nurses. All nurses can monitor the patient. Chemo drugs are desiccants and can cause extravasation (necrosis if the drug leaks into tissue); patent IV access is critical.     * Oral Chemotherapy: Can be taken at home. Patients must swallow tablets whole; they must not be crushed, split, broken down, or chewed.

  • Safety: Nurses must wear chemo-approved Personal Protective Equipment (PPE) when preparing, administering, disposing of, or handling waste to avoid absorbing toxic drugs.

Side Effects of Cancer Therapy

  • Radiation Side Effects:     * Radiation Dermatitis: Most common acute local effect (redness, rash, skin desquamation/peeling).     * Fatigue: Acute systemic effect due to increased energy demand for cell repair. Management: Balance rest and activity.     * Altered Taste: Due to metabolites from dead cells. Management: Hydration of oral mucosa and small meals.     * Long-Term Effects: Rare, but include tissue scarring (e.g., difficulty swallowing/breathing years later) and cardiovascular issues.     * Cardiovascular Side Effects: Damage to blood vessels leads to collateral circulation (alternative vessel formation) and accelerated atherosclerosis (plaque buildup), increasing the risk for Coronary Artery Disease, Stroke, and Peripheral Vascular Disease.

  • Chemotherapy Side Effects:     * Alopecia: Thinning or total hair loss; grows back one month after therapy with different texture/color. Management: Protect the skull from injury and address body image.     * GI Effects: Chemo-induced nausea and vomiting (CINV) is the most common dose-limiting side effect. Management: Anti-emetics or cytoprotectants/chemoprotectors given before treatment.     * Mucositis: Sores in the mouth/intestines.     * Bone Marrow Suppression: Reduction in blood cells leading to anemia, fatigue, infection, and bleeding.     * Nadir: The period when bone marrow activity is at its lowest after chemo (77 to 1212 days post-treatment). Example: If chemo is given on 11/511/5, the nadir is between 8/128/12 and 11/1711/17.     * Chemo Brain: Temporary cognitive changes like loss of concentration and memory, triggered by systemic inflammation/biochemical changes.     * Peripheral Neuropathy (CIPN): Loss of sensory/motor function. Symptoms include lost sensation in hands/feet, impaired gait, orthostatic hypotension, erectile dysfunction (ED), and severe constipation.

Oncologic Emergencies

  • Spinal Cord Compression: Tumor compresses the spinal cord, causing severe pain and potential neurologic damage.     * Symptoms: Back pain, weakness, loss of sensation, urinary retention, and constipation.     * Management: Initial high-dose IV steroid bolus (tapered over time) to relieve inflammation; radiation, surgery, or external braces.

  • Superior Vena Cava Syndrome (SVCS): Compression of the SVC by a tumor or clot, common in late-stage cancer.     * Early Symptoms: Edema of the face (periorbital edema worse in the AM), JVD, tightness around the collar, head fullness.     * Worsening Signs: Upper body edema, cough, dyspnea. Stridor is an alarming sign of rapid SVCS.     * Management: Radiation (temp relief), chemotherapy (long term), or stents.

  • Sepsis: Initiated by bone marrow suppression and neutropenia.     * Progression: Infection →\rightarrow inflammation →\rightarrow poor perfusion →\rightarrow low oxygen →\rightarrow lactic acidosis →\rightarrow organ failure.     * Management: Oxygen therapy, fluid therapy, blood cultures, antibiotics, and vasopressors.

  • Disseminated Intravascular Coagulation (DIC): A cycle of widespread clotting and subsequent bleeding triggered commonly by Gram-negative sepsis.     * Pathophysiology: Endotoxins damage vessels →\rightarrow micro-clots form →\rightarrow clotting factors/platelets are consumed →\rightarrow uncontrolled bleeding/oozing from IV sites.     * Symptoms: Ischemia, pain, dyspnea, tachycardia, reduced kidney function, bowel necrosis.     * Management: Treat the trigger (IV Abx), manage bleeding, and replace depleted factors (transfusions).

  • SIADH: Syndrome of Inappropriate Anti-Diuretic Hormone.     * Cause: Tumors (e.g., lung cancer) secrete ADH or stimulate the pituitary to do so.     * Effect: Excess water reabsorption →\rightarrow Dilutional Hyponatremia.     * Symptoms: Seizures, fluid overload, pulmonary congestion, peripheral edema.     * Management: Fluid restriction, increased sodium intake, cancer therapy to reduce the tumor.

  • Tumor Lysis Syndrome (TLS): Sign of effective therapy as cells break down, releasing internal components.     * Pathophysiology: Release of Potassium (K+K^+), Phosphorus, and Uric Acid. High Phosphorus causes low Calcium (Ca2+Ca^{2+}).     * Risks: Arrhythmias (K+K^+), seizures (Low Ca2+Ca^{2+}), and urolithiasis/kidney injury (Uric Acid).     * Management: Hydration (to dilute K+K^+), monitoring electrolytes, Allopurinol (for uric acid), and Sodium Polystyrene Sulfonate (for K+K^+).

  • Hypercalcemia: A metabolic emergency occurring in ≈1/3\approx 1/3 of patients.     * Cause: Cancer cells secrete parathyroid hormones or Vitamin D analogs, or bone metastasis causes bone breakdown.     * Management: IV fluid therapy (to flush electrolytes), loop diuretics, bisphosphonates, or dialysis.

Assessment and Nursing Cues

  • Personal and Family History Risk Factors:     * Same cancer in multiple generations or first-degree relatives.     * Cancer at an unusually young age.     * Cancer in bilateral organs.     * Breast cancer in adult males.     * Diet: Low fiber, high red meat/animal fat, preservatives, additives.     * Lifestyle: Smoking, inactivity, obesity.

  • Physical Assessment (CAUTION Acronym):     * C: Changes in bowel or bladder habits.     * A: A sore that does not heal.     * U: Unusual bleeding or discharge.     * T: Thickening or lump in the breast or elsewhere.     * I: Indigestion or difficulty swallowing.     * O: Obvious change in wart or mole.     * N: Nagging cough or hoarseness.

  • Labs and Diagnostics: CBC, BMP, Amylase, Lipase, Lactate Dehydrogenase (LDH), Alkaline Phosphatase (ALP), Prostate-Specific Antigen (PSA), X-ray, MRI, CT, and Biopsy.

  • Incidence Statistics (2025 Data):     * > 2\,million new cancer cases.     * > 600,000 deaths.

Analysis and Priority Nursing Goals

  • Analyzed Hypotheses:     * Altered Tissue Integrity (stomatitis, dermatitis, alopecia).     * Altered GI Function/Nutrition (Cachexia, early satiety due to high metabolism).     * Activity Intolerance related to fatigue.     * Impaired Immunity and Clotting (Reduction in WBC, RBC, and platelets).     * Altered Respiratory/Cardiac Function (Tumor obstruction or therapy effects).

  • Nursing Priorities:     1. Manage side effects of treatment.     2. Manage oncologic emergencies.     3. Manage pain and discomfort (especially in advanced stages).     4. Prevent complications.

  • Overall Goals: To cure or control cancer, manage symptoms of affected organ systems, and manage the side effects of therapy.