Cancer & Malignancy- Level 2

Biology of Cancer

Two Main Dysfunctions

  1. Defective Cellular Proliferation (Growth): Cancer cells grow uncontrollably.

  2. Defective Cellular Differentiation: Cancer cells don't mature into specialized cells as they should.

  • These dysfunctions are key to understanding how cancer develops and progresses.

Cellular Proliferation (Normal Cells)

  • Normal cells have checks and balances to maintain equilibrium.

  • The rate of proliferation varies in different tissues:

    • Rapid proliferation: bone marrow, hair follicles, epithelial cells

    • Slow proliferation: muscle cells, nerve cells

Defect in Cellular Proliferation (Cancer Cells)

  • Cancer cells ignore normal boundaries and invade other tissues.

  • They grow on top of and between normal cells, leading to a pyramid effect (1, 2, 4, 8, 16, …).

Cell Differentiation

  • Stem cells differentiate into specialized cells (e.g., muscle, blood, nerve, cardiac, intestinal, liver cells).

Genetic Links and Malfunctions

  • Mutations in normal genes can lead to cancer.

  • Two types of genes are affected:

    • Proto-oncogenes: Normal genes that regulate cell growth and differentiation. When mutated, they become oncogenes.

    • Tumor Suppressor Genes: Regulate and inhibit inappropriate cellular growth and proliferation. When these genes are inactivated, the ability of cells to regulate growth is lost

    • Oncogenes: Tumor-inducing genes that produce proteins, hormones, and antigens (tumor markers).

Theory of Cancer Development

The process occurs in three stages:

  1. Initiation:

    • The first stage involves mutation of the cell's genetic structure, which can be inherited or acquired.

  2. Promotion:

    • The second stage, which is often reversible, involves the proliferation of altered cells.

    • Promoting factors include obesity, tobacco use, alcohol use, unhealthy diet, and physical inactivity.

    • Prevention is key in this stage.

  3. Progression:

    • The third stage involves increased growth rate and invasiveness of the tumor, as well as metastasis.

Carcinogens

  • Cancer-causing agents include chemicals, radiation, viruses, hormones, and unknown factors.

Latent Period

  • The time between the initial genetic mutation and the clinical evidence of cancer.

Metastasis

  • The rapid growth of the primary tumor leads to angiogenesis (development of its own blood supply).

  • Tumor cells detach, invade surrounding tissues, and travel to distant sites via lymph nodes and blood vessels.

  • Most mobile tumor cells do not survive, but those that do must create an environment conducive to growth.

  • Common sites of metastasis include the brain, cerebrospinal fluid, lung, liver, adrenals, and bone.

Role of the Immune System

  • The immune system differentiates between normal (self) and abnormal (non-self) cells and attempts to reject or destroy cancer cells.

  • This response may be inadequate.

  • Cancer cells may have altered surface antigens called tumor-associated antigens (TAAs).

  • Immunologic surveillance is the process of the immune system monitoring and destroying cancer cells.

Oncofetal Antigens and Tumor Markers

  • Oncofetal antigens are found on tumor cell surfaces, inside tumor cells, and fetal cells.

  • They are not well understood but can be used as tumor markers.

  • Examples include carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), CA-125, CA-19-9, CA-15-3, CA-27-29, PSA, and HER-2.

Benign vs. Malignant Tumors

  • Tumors can be classified as benign or malignant.

  • The major difference is the ability of malignant tumor cells to invade and metastasize.

Tumor Classification

  • Classified by:

    • Anatomic site

    • Histology (grading)

    • Extent of disease (staging)

Purpose of Cancer Classification

  • To facilitate communication, decision-making for treatment, evaluation of treatment, prognosis, and comparison of groups.

Anatomic Site Classification

  • Based on the tissue of origin, anatomic site, and tumor behavior.

    • Carcinomas: arise from skin, glands, mucous membranes of respiratory, GI, and GU tracts.

    • Sarcomas: arise from connective tissue, muscle, bone, and fat.

    • Lymphomas & leukemias: originate in the hematopoietic system.

Histologic Classification (Grading)

  • Evaluates the appearance of cells and the degree of differentiation to determine how closely cells resemble the tissue of origin.

    • Grade I: Well-differentiated (low grade).

    • Grade II: Moderately differentiated (intermediate grade).

    • Grade III: Poorly differentiated (high grade).

    • Grade IV: Undifferentiated (high grade).

    • Grade X: Grade cannot be assessed.

Extent of Disease: Clinical Staging

  • Stage 0: Cancer in situ.

  • Stage I: Localized tumor.

  • Stage II: Limited local spread.

  • Stage III: Extensive local and regional spread.

  • Stage IV: Distant metastasis.

TNM Classification System

  • T (Primary Tumor):

    • T0: No evidence of primary tumor.

    • Tis: Carcinoma in situ.

    • T1-4: Ascending degrees of increase in tumor size and involvement.

    • Tx: Tumor cannot be measured or found.

  • N (Regional Lymph Nodes):

    • N0: No evidence of disease in lymph nodes.

    • N1-4: Ascending degrees of nodal involvement.

    • Nx: Regional lymph nodes unable to be assessed clinically.

  • M (Distant Metastases):

    • M0: No evidence of distant metastasis.

    • M1-4: Ascending degrees of metastatic involvement.

    • Mx: Cannot be determined.

Prevention and Early Detection

  • Focus on reducing risk factors and promoting early detection through screening.

Cancer's Early Warning Signs (CAUTION)

  • Change in bowel or bladder habits

  • A sore that does not heal

  • Unusual bleeding or discharge

  • Thickening or lump in the breast or elsewhere

  • Indigestion or difficulty swallowing

  • Obvious change in a wart or mole

  • Nagging cough or persistent hoarseness

Diagnosis of Cancer

  • Histology and cytology studies

  • Labs: CBC, chemistry profile, LFTs

  • Endoscopic examinations

  • Radiographic studies: Chest x-ray, US, CT scan, MRI, PET scan

  • Radioisotope scans

  • Tumor markers

  • Genetic markers

  • Molecular receptor status

  • Bone marrow examination

  • Biopsy

Biopsy

  • Removal of a tissue sample for pathologic analysis.

  • Tissue may be obtained by:

    • Needle aspiration

    • Incisional procedure

    • Excisional procedure

Goals of Cancer Treatment

  • Cure: Eradicating the cancer and achieving long-term disease-free survival.

  • Control: Managing the cancer to prevent further growth and spread, similar to managing chronic diseases.

  • Palliation: Relieving symptoms and improving quality of life when a cure is not possible.

Personalized Cancer Medicine

  • Emerging trend that uses a patient's genetic information to guide decisions about prevention, diagnosis, and treatment.

Treatment Modalities

Surgery

  • Used for:

    • Diagnosis (biopsy)

    • Clinical staging

    • Cure and/or control of cancer (removal of localized cancer tissue)

    • Supportive care (insertion of therapeutic devices)

    • Palliation of symptoms (relief of pain, obstruction, hemorrhage)

    • Rehabilitation (reconstructive surgery)

    • Prevention (removal of nonvital organs to prevent cancer)

Chemotherapy

  • Factors determining response:

    • Mitotic rate

    • Size of the tumor

    • Age of the tumor

    • Location of the tumor

    • Presence of resistant tumor cells

  • Classifications:

    • Cell cycle phase-nonspecific: Acts at any point in the cell cycle.

    • Cell cycle phase-specific: Interrupts cell division at specific points.

  • Combination therapy: Multiple agents to achieve greater cell kill and fewer resistant cell lines.

Chemical Structure Classifications

  • Alkylating agents

  • Antitumor antibiotics

  • Nitrosureas

  • Platinum Drugs

  • Antimetabolites

  • Mitotic Inhibitors

  • Topoisomerase Inhibitors

Chemotherapy Routes of Administration

  • Oral

  • Intraarterial

  • Intracavitary (pleural, peritoneal)

  • Intramuscular

  • Intrathecal

  • Intravenous

  • Subcutaneous

  • Topical

  • Complications can arise from extravasation.

Chemotherapy Side Effects

  • Alopecia

  • Myelosuppression

  • GI disturbances

  • Sterility

  • Renal toxicity

  • Liver toxicity

  • Cardiopulmonary toxicity

Radiation Therapy

  • Aim is to destroy malignant cells with beams.

  • Both normal and cancer cells are affected.

  • Nondividing/slow dividing cells are generally less radiosensitive.

  • Tumor cells are not able to repair DNA damage, while normal cells are.

  • Types:

    • Teletherapy (External Beam): Most widely used, focused from a source outside the body, allows larger areas to be treated, usually given 5 days/week over 2-7 weeks.

    • Brachytherapy (Internal Radiation): Placed directly on or near the tumor, used alone or with other therapies, sources (sealed) such as seeds or ribbons.

Radiation Safety

  • Time: Limit the amount of time near the source.

  • Distance: Maximize the distance from the source.

  • Shielding: Use appropriate shielding materials.

Nursing Management for Chemo/Radiation

  • Bone marrow suppression

  • Fatigue

  • GI problems

  • Skin reactions

  • Pulmonary reactions

  • Cardiovascular reactions

  • Cognitive reactions

  • Reproductive effects

Myelosuppression

  • Reduction in red blood cells, white blood cells, and platelets.

  • Nadir: Blood counts drop in 7-10 days post-treatment; the lowest known count (neutrophil, platelet, and RBC count).

GI Side Effects

  • Nausea

  • Vomiting

  • Anticipatory nausea & vomiting

  • Delayed nausea & vomiting

  • Diarrhea

  • Mucositis

  • Anorexia

Skin Reactions

  • Dry areas

  • Redness

  • Weeping (wet desquamation)

  • Hand/foot reaction

  • Alopecia

Pulmonary Reactions

  • Cough

  • SOB

  • Pneumonitis

  • Pulmonary fibrosis

Cardiovascular Reactions

  • ECG changes

  • LV Dysfunction

  • Heart failure

  • Cardiac Ischemia

Cognitive Reactions

  • Alteration in Mental Function

  • Thinking and Memory Problems

Reproductive Effects

  • Sperm count

  • ED

  • Ovarian failure

  • Change in cervix

  • Infertility

Immunotherapy and Targeted Therapy

  • Immunotherapy uses the immune system to fight cancer by boosting or manipulating the immune system or attacking cancer cells directly.

  • Targeted therapies interfere with cancer growth.

Hormone Therapy

  • Sex hormones can stop the growth of cancer cells.

  • Corticosteroids are used in combination with drug regimens to help curb side effects.

Bone Marrow & Stem Cell Transplant

  • Harvest stem cells or bone marrow, treat with agents that destroy malignant cells without harming normal cells, administer IV injection of purified stem cells after chemotherapy.

Complications of Cancer

  • Arising from continual growth of the cancer or side effects of treatment.

Nutritional Problems

  • Malnutrition

  • Altered taste sensation

  • Cancer cachexia

  • Leading cause of death in patients with cancer is infection.

Oncologic Emergencies

  • Occur as a result of the disease or treatment, are life-threatening, and can be obstructive, metabolic, or infiltrative.

    • Obstructive:

      • SVC syndrome

      • Spinal cord compression

    • Metabolic:

      • SIADH

      • Hypercalcemia

      • Tumor lysis syndrome

      • Septic Shock

    • Infiltrative:

      • Cardiac tamponade

      • Carotid artery rupture

Pain Management

  • Patient should always be believed and accepted as the primary source for pain assessment data.

  • Drug therapy should be used to control pain.

  • Undertreatment of pain causes unnecessary suffering.

  • Inadequate pain assessment is the single greatest barrier to effective cancer pain management.

Nursing Interventions for Pain Management

  • Pain diary

  • Patient education

  • Drug therapy

  • Non-pharmacologic methods

Coping with Cancer and Treatment

Many factors influence coping like demographics, prior coping skills and strategies, social support, and religious and spiritual beliefs.

During and after radiation therapy, it's generally advisable to avoid large crowds, especially if your white blood cell count is low, as radiation can suppress the immune system, increasing the risk of infection. As for flushing the toilet twice, this is a precaution often recommended after receiving certain types of internal radiation therapy to ensure that any bodily fluids containing radioactive material are properly disposed of.