oncology

ONCOLOGY STUDY NOTES

OVERVIEW

  • Presented by Angela Njenga, PhD, MHA, BSN

  • Date: April 2026

CELLULAR GROWTH AND REGULATION

  • Concepts to Understand:   - Cells grow in an orderly manner to facilitate body development until maturity.   - To maintain homeostasis, old cells must be replaced by new ones through a strict cellular regulation process.   - During cellular regulation, genes interact to control cell growth, replication, and differentiation.   - Cells grow and mature through a process of promotion and suppression until they are no longer needed.

KEY CONCEPTS

  • Normal Cellular Growth:
      - Must follow an orderly and strictly regulated process.

  • Cellular Regulation:   - Orderly + Strictly Promotion = Suppression

  • Breakdown in cellular promotion and suppression can lead to abnormal cellular regulation, resulting in neoplasia (abnormal cell growth).

NEOPLASIA

  • Neoplasm Definition:   - An abnormal cell growth or abnormal cell function. Neoplastic cells do not function normally and exhibit characteristics different from normal cells.

  • Classification of Neoplasms:   - Benign (Non-cancerous):
        - Continuous and inappropriate growth that expands but remains contained, with normal genes.   - Malignant (Cancerous):
        - Rapid growth, invasive behavior, with defective or mutated genes.

CANCER CLASSIFICATION

  • Cancers can be classified by:   - Tissue type
      - Biological behavior
      - Anatomic site
      - Degree of differentiation.

  • Importance of Grading and Staging:   - Confirms diagnosis, determines prognosis, and guides treatment decisions.

CAUSES OF CANCER (ETIOLOGY)

  • Carcinogenesis (Oncogenesis):   - The process of cancer development taking years.   - Dependent on three interacting factors:
        1. Exposure to a carcinogen
        2. Genetic disposition
        3. Immunity

  • Not all cells are susceptible to carcinogenesis.

EXTERNAL FACTORS

  • Chemical Carcinogens:
      - Tobacco, alcohol, drugs, chemicals in everyday products. Some act as co-carcinogens.

  • Physical Carcinogens:
      - Radiation (UV exposure) and chronic irritation (e.g., gastritis, GERD).

  • Viral Carcinogens:
      - Oncoviruses like HPV, HBV, EBV; bacterial sources like H. pylori.

PERSONAL FACTORS

  • Immunity:   - Reduced immunity due to age, organ transplants, or AIDS.

  • Genetic Disposition:   - Refer to chart in Nursing Practice on p. 267 (for information).

  • Hormonal Changes:
      - Related to hormone production or hormonal therapy.

  • Lifestyle Factors:   - Smoking, poor diet, physical inactivity.

CARCINOGENESIS PROCESS

  • Stages of Carcinogenesis:   - Initiation and Promotion Stage:
        - Carcinogens alter genetic activity, leading to cancer cell formation.     - Promoter substances enhance growth, leading to tumor formation.     - Loss of cellular regulation promotes excessive division.   - Progression Stage:
        - Tumor grows a new blood supply (angiogenesis) to sustain itself.

  • Metastatic Stage:
      - Cancer cells penetrate blood vessels from the primary tumor, leading to secondary cancer or metastatic tumors.

CANCER PREVENTION

  • Primary Prevention:   - Strategies to prevent the actual occurrence of cancer, including:     - Avoiding known carcinogens (e.g., smoking).     - Modifying lifestyle factors (e.g., diet).     - Removing at-risk tissues (e.g., polyps).     - Using chemoprevention drugs.     - Vaccination (e.g., HPV).

  • Secondary Prevention:   - Focus on screening for early cancer detection (e.g., prostate exams, colonoscopy, mammography).

CANCER THERAPIES

  • Types of Cancer Therapy:   - Surgery, biological therapies, chemotherapy, radiation therapy.   - Can be used alone or in combination (multimodal approach).   - Therapy options depend on type, stage, and overall patient function.

RADIATION THERAPY

  • Mechanism:
      - Uses high-energy radiation to kill cancer cells or control symptoms.   - Can be given in divided doses due to differing responses in cancer cells.   - Two forms: Local (external beam therapy, teletherapy) & Systemic (internal, brachytherapy).   

RADIATION THERAPY CONT'D

  • Effects:   - Affects targeted cancer cells with minimal damage to normal tissues (those in the direct path of radiation).   - Precise skin markings made to ensure minimal damage during therapy.   - Patients receiving this type are not radioactive after treatment.

CHEMOTHERAPY

  • Mechanism:
      - Uses chemical agents that kill cancer cells.   - Damages DNA and interferes with cellular division, effective against rapidly growing tumors.   - Affects other rapidly dividing cells (skin, hair, intestines, blood-forming cells).   - Administered regularly to maximize cancer cell effects and allows normal cell recovery.

SIDE EFFECTS OF RADIATION THERAPY

  • Short-Term Effects:
      - Radiation dermatitis, fatigue, altered taste.   - Management includes hydration and balanced activity/rest.

  • Long-Term Effects:
      - Tissue scarring, cardiovascular side effects, risk of atherosclerosis due to vascular damage.

SIDE EFFECTS OF CHEMOTHERAPY

  • Common Side Effects:   - Alopecia (hair loss), gastrointestinal disturbances (nausea/vomiting), blood cell dysregulation (anemia, increased infection risk).   - Important to monitor nadir (period of lowest bone marrow activity after therapy).

  • Cognitive Effects:
      - Temporary changes in memory and concentration (chemobrain), peripheral neuropathy.

ONCOLOGIC EMERGENCIES

Spinal Code Compression

  • Can cause severe pain and neurologic damage.

  • Management includes IV steroids, radiation, and possibly surgery to relieve compression.

Superior Vena Cava Syndrome

  • Caused by compression from a tumor or clot leading to blood congestion and potential life-threatening symptoms.

  • Management includes radiation therapy for relief and chemotherapy for long-term control.

Sepsis Management

  • Due to bone marrow suppression, leading to lack of immunity.

  • Treatment includes oxygen therapy, fluid therapy, antibiotics.

Disseminated Intravascular Coagulation (DIC)

  • A life-threatening cycle of clotting and bleeding.

  • Triggered by severe infections (often septic).

  • Treatment involves rapid management of sepsis and bleeding risk.

Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

  • Results in water overload and dilutional hyponatremia.

  • Management includes fluid restriction, increased sodium intake, and drug therapy.

Tumor Lysis Syndrome

  • Indicates effective cancer therapy.

  • Requires monitoring and management of electrolytes (e.g., potassium, phosphorus).

Hypercalcemia

  • Can occur in 1/3 of cancer patients, leading to potential death.

  • Management includes IV fluids, diuretics, and bisphosphonates if necessary.

ASSESSMENT AND PRIORITY

Cues and Expected Findings

  • Personal and family history of cancer, dietary habits, lifestyle factors (smoking, inactivity).

  • Physical assessment cues: changes in bowel habits, non-healing sores, unusual bleeding, weight changes, persistent cough.

LABORATORY AND DIAGNOSTIC TESTS

  • Varying tests including CBC, BMP, imaging studies (X-ray, MRI, CT), and biopsies for diagnosis.

  • Incidence Data: Over 2 million new cases in 2025 with over 600,000 deaths from cancer.

MANAGEMENT STRATEGY

  • Multi-dimensional approach:   - Tailored cancer therapy (surgery, radiation, chemotherapy, immunotherapy).   - Symptom and pain management, addressing quality of life issues.   - Referral to counseling and support groups.   - Palliative care options as needed.   - Goals of treatment focus on curing, controlling cancer, and managing symptoms.