💊Pharmacology for Nurses Unit 8 – Cancer Therapy: Intro to Drugs and Treatment

What is Cancer?

• Characterized by uncontrolled growth and spread of abnormal cells in the body
• Caused by mutations in genes that regulate cell growth and division
• Can originate from any type of cell in the body (epithelial, connective, muscle, or nerve tissue)
• Develops when the balance between cell proliferation and cell death is disrupted
• Tumors can be benign (non-cancerous) or malignant (cancerous)
  • Benign tumors do not invade nearby tissues or spread to other parts of the body
  • Malignant tumors can invade and damage nearby tissues and organs, and spread to other parts of the body through the bloodstream or lymphatic system (metastasis)
• Risk factors include genetic predisposition, environmental factors (exposure to carcinogens), and certain lifestyle choices (smoking, poor diet)
• Can lead to a variety of symptoms depending on the location and extent of the disease (pain, fatigue, weight loss, bleeding)

Types of Cancer and Their Characteristics

• Carcinomas originate from epithelial cells that line internal and external body surfaces (skin, lungs, breasts, colon)
  • Adenocarcinomas develop from glandular epithelial cells (breast, prostate, colon)
  • Squamous cell carcinomas arise from squamous epithelial cells (skin, lungs, esophagus)
• Sarcomas develop from connective tissues (bones, cartilage, fat, muscle)
  • Osteosarcoma originates from bone cells
  • Liposarcoma arises from fat cells
• Leukemias and lymphomas affect blood-forming tissues and the immune system
  • Leukemias involve abnormal growth of white blood cells in the bone marrow and blood
  • Lymphomas affect lymphocytes (a type of white blood cell) in the lymphatic system
• Central nervous system cancers develop in the brain and spinal cord (gliomas, meningiomas)
• Each type of cancer has unique characteristics, including growth patterns, metastatic potential, and response to treatment

Cancer Treatment Goals

• Primary goal is to cure the cancer by completely eliminating all cancerous cells from the body
• If a cure is not possible, treatment aims to control the growth and spread of the cancer to prolong survival and improve quality of life
• Palliative care focuses on relieving symptoms and improving comfort for patients with advanced or terminal cancer
• Treatment plans are individualized based on the type and stage of cancer, as well as the patient's overall health and preferences
• Multidisciplinary approach involves collaboration among oncologists, surgeons, radiation oncologists, and other healthcare professionals
• Regular monitoring and follow-up care are essential to detect recurrence or progression of the disease

Overview of Cancer Therapies

• Surgery involves removing the cancerous tumor and surrounding tissue
  • Can be curative for localized cancers that have not spread
  • May be combined with other therapies (chemotherapy, radiation) to improve outcomes
• Radiation therapy uses high-energy radiation to damage or kill cancer cells
  • External beam radiation is delivered from a machine outside the body
  • Internal radiation (brachytherapy) involves placing radioactive material directly into or near the tumor
• Chemotherapy uses drugs to kill rapidly dividing cancer cells throughout the body
  • Can be administered orally, intravenously, or through other routes (intrathecal, intraperitoneal)
  • Often given in cycles with periods of rest to allow recovery from side effects
• Targeted therapy focuses on specific molecules involved in cancer cell growth and survival
  • Monoclonal antibodies bind to specific proteins on the surface of cancer cells (trastuzumab for HER2-positive breast cancer)
  • Small molecule inhibitors block the activity of enzymes or other proteins involved in cancer cell signaling (imatinib for chronic myeloid leukemia)
• Immunotherapy harnesses the power of the immune system to fight cancer
  • Checkpoint inhibitors block proteins that prevent immune cells from attacking cancer cells (pembrolizumab for melanoma)
  • CAR T-cell therapy involves genetically modifying a patient's own T cells to target and destroy cancer cells (tisagenlecleucel for certain types of leukemia and lymphoma)
• Hormone therapy is used for cancers that are sensitive to hormones (breast, prostate)
  • Blocks the production or action of hormones that stimulate cancer cell growth (tamoxifen for estrogen receptor-positive breast cancer)

Common Cancer Drugs and Their Mechanisms

• Alkylating agents damage DNA by adding alkyl groups, preventing cancer cells from dividing (cyclophosphamide, cisplatin)
• Antimetabolites interfere with DNA and RNA synthesis by mimicking normal metabolites (5-fluorouracil, methotrexate)
• Plant alkaloids inhibit cell division by targeting microtubules (vincristine, paclitaxel)
• Topoisomerase inhibitors block enzymes involved in DNA replication and transcription (doxorubicin, etoposide)
• Monoclonal antibodies target specific proteins on the surface of cancer cells (rituximab for non-Hodgkin's lymphoma)
• Tyrosine kinase inhibitors block enzymes involved in cell signaling and growth (erlotinib for non-small cell lung cancer)
• Proteasome inhibitors block the breakdown of proteins involved in cell cycle regulation (bortezomib for multiple myeloma)
• PARP inhibitors prevent the repair of DNA damage in cancer cells with BRCA mutations (olaparib for ovarian cancer)

Side Effects and Management

• Chemotherapy can cause a wide range of side effects due to its effects on rapidly dividing cells throughout the body
  • Myelosuppression (decreased production of blood cells) can lead to anemia, neutropenia, and thrombocytopenia
    • Managed with blood transfusions, growth factors (filgrastim), and dose adjustments
  • Gastrointestinal side effects include nausea, vomiting, diarrhea, and mucositis
    • Treated with antiemetics (ondansetron), antidiarrheals (loperamide), and supportive care
  • Hair loss (alopecia) is a common and distressing side effect of many chemotherapy drugs
    • Managed with scalp cooling, wigs, and emotional support
• Targeted therapies and immunotherapies have more specific side effect profiles related to their mechanisms of action
  • Skin rashes, diarrhea, and liver function abnormalities are common with tyrosine kinase inhibitors
  • Immune-related adverse events (irAEs) can occur with checkpoint inhibitors, including colitis, pneumonitis, and endocrinopathies
    • Managed with corticosteroids and other immunosuppressive agents
• Supportive care measures are essential to manage side effects and maintain quality of life
  • Pain management, nutrition support, and psychosocial interventions are key components of comprehensive cancer care

Treatment Strategies and Protocols

• Neoadjuvant therapy is given before the primary treatment (usually surgery) to shrink the tumor and improve outcomes
  • Commonly used in breast, rectal, and esophageal cancers
• Adjuvant therapy is given after the primary treatment to reduce the risk of recurrence
  • Chemotherapy, radiation, and targeted therapies can be used in the adjuvant setting
• Combination therapy involves using multiple treatment modalities simultaneously or sequentially
  • Can enhance efficacy, overcome resistance, and target different aspects of the cancer
  • Examples include chemoradiation for locally advanced cancers and chemotherapy plus targeted therapy for metastatic disease
• Clinical trials are research studies that evaluate new treatments or treatment strategies
  • Provide access to innovative therapies and contribute to the advancement of cancer care
  • Patients should be informed about the potential risks and benefits of participating in a clinical trial

Nursing Considerations in Cancer Care

• Nurses play a critical role in the care of cancer patients throughout the continuum of care
  • Administer chemotherapy and other cancer treatments safely and effectively
  • Monitor patients for side effects and toxicities, and implement appropriate interventions
  • Educate patients and families about the disease, treatment options, and self-care strategies
• Symptom management is a key nursing responsibility
  • Assess and manage pain using pharmacologic and non-pharmacologic approaches
  • Prevent and treat chemotherapy-induced nausea and vomiting (CINV) with antiemetics and complementary therapies
  • Address nutritional issues, including anorexia, cachexia, and taste changes
• Psychosocial support is essential to help patients and families cope with the physical, emotional, and social impact of cancer
  • Provide emotional support, active listening, and referrals to support services (counseling, support groups)
  • Assess for distress, anxiety, and depression, and collaborate with mental health professionals as needed
• Survivorship care focuses on the long-term needs of cancer survivors
  • Monitor for late effects of treatment, such as cardiovascular disease, second malignancies, and cognitive impairment
  • Promote healthy lifestyle behaviors (physical activity, nutrition) to reduce the risk of recurrence and improve overall health
  • Address psychosocial concerns, such as fear of recurrence, body image issues, and relationship challenges