Angelite Nurses

PATHOPHYSIOLOGY AND ETIOLOGY OF CANCER

Evolution of Cancer Cells

1. All cells constantly change through growth, degeneration, repair, and adaptation. Normal cells must divide and multiply to meet the needs of the organism as a whole, and this cycle of cell growth and destruction is an integral part of life processes. The activities of the normal cells in the human body are all coordinated to meet the needs of the organism as a whole, but when the regulatory control mechanisms of normal cells fail, and growth continues in excess of the body's needs, neoplasia results.
2. The term neoplasia refers to both benign and malignant growths, but malignant cells behave very differently from normal cells and have special features characteristic of the cancer process.
3. Since the growth control mechanism of normal cells is not entirely understood, it is not clear what allows the uncontrolled growth, therefore no definitive cure has been found.

Characteristics of Malignant Cells


Differentiation

1. Cancer cells are mutated stem cells that have undergone structural changes so that they are unable to perform the normal functions of specialized tissue (un- or dedifferentiation).
2. They may function in a disorderly way or cease normal function completely, only functioning for their own survival and growth.
3. The most undifferentiated cells are also called anaplastic.

Rate of Growth

1. Cancer cells have uncontrolled growth or cell division.
2. Rate at which a tumor grows involves both increased cell division and increased survival time of cells.
3. Malignant cells do not form orderly layers, but pile on top of each other to eventually form tumors.

Spread (Invasion and Metastasis)

1. Cancer cells are less adhesive than normal cells, more easily dissociated from their location.
2. Lack of adhesion and loss of contact inhibition make it possible for a cancer to spread to distant parts of the body (metastasis).
3. Malignant tumors are not encapsulated and expand into surrounding tissue (invasion).

Etiology (Carcinogenesis)
Actual cause of cancer is unknown but there are a number of theories; it is currently thought that there are probably multiple etiologies.

Environmental Factors

1. Majority (over 80%) of human cancers related to environmental carcinogens
2. Types
1. Physical
1. Radiation: x-rays, radium, nuclear explosion or waste, ultraviolet
2. Trauma or chronic irritation
2. Chemical
1. Nitrites and food additives, polycyclic hydrocarbons, dyes, alkylating agents
2. Drugs: arsenicals, stilbestrol, urethane
3. Cigarette smoke
4. Hormones

Genetics

1. Some cancers show familial pattern.
2. May be caused by inherited genetic defects.

Viral Theory

1. Viruses have been shown to be the cause of certain tumors in animals.
2. Oncoviruses (RNA-type viruses) thought to be culprit.
3. Viruses (HTLV-I, Epstein-Barr, Human Papilloma Virus) linked to human tumors.

Immunologic Factors

1. Failure of the immune system to respond to and eradicate cancer cells
2. Immunosuppressed individuals more susceptible to cancer

DIAGNOSIS OF CANCER

Classification and Staging


Tissue of Origin

1. Carcinoma: arises from surface, glandular, or parenchymal epithelium.
1. Squamous cell carcinoma: surface epithelium
2. Adenocarcinoma: glandular or parenchymal tissue
2. Sarcoma: arises from connective tissue.
3. Leukemia, lymphoma, and multiple myeloma: separate categories for each

Stages of Tumor Growth

1. Several staging systems, important in selection of therapy
1. TNM system: uses letters and numbers to designate the extent of the tumor.
1. T: stands for primary growth; 1-4 with increasing size. T1S indicates carcinoma in situ.
2. N: stands for lymph node involvement; 0-4 indicates progressively advancing nodal disease.
3. M: stands for metastasis; 0 indicates no distant metastases, 1 indicates presence of metastases.
2. Stages 0-IV: all cancers divided into five stages incorporating size, nodal involvement, and spread.
2. Cytologic diagnosis of cancer (e.g., Pap smear)
1. Involves study of shed cells
2. Classified by degree of cellular abnormality
1. Normal
2. Probably normal (slight changes)
3. Doubtful (more severe changes)
4. Probably cancer or precancerous
5. Definitely cancer

Client Factors
Early detection of cancer is crucial in reducing morbidity and mortality. Clients need to be taught about

1. Seven warning signs of cancer (see Table 4.14).
2. Breast self-examination (BSE) (see Figure 6.11 in Unit 6).
3. Importance of rectal exam for those over age 40
4. Hazards of smoking
5. Oral self-examination as well as annual exam of mouth and teeth
6. Hazards of excess sun exposure
7. Importance of Pap smear
8. Physical exam with lab work-up: every 3 years ages 20-40; yearly age 40 and over
9. Testicular self-examination (TSE)
1. Testicular Cancer: Most common cancer in young men between the ages of 15 and 34. Most testicular cancers are found by men themselves, by accident or when doing TSE.
2. Testicular Self-Examination: Ideally, should be performed monthly, after a warm shower or bath, when the skin of the scrotum is relaxed. Standing in front of a mirror, the man should gently roll each testicle between the thumb and fingers of both hands. The testes are smooth, oval-shaped, and rather firm.
3. Warning Signs That Men Should Look For:
1. Painless swelling
2. Feeling of heaviness
3. Hard lump (size of a pea)
4. Sudden collection of fluid in the scrotum
5. Dull ache in the lower abdomen or in the groin
6. Pain in a testicle or in the scrotum
7. Enlargement or tenderness of the breasts

TABLE 4.14 Seven Warning Signs of Cancer (Caution)

TREATMENT OF CANCER

Chemotherapy


Principles

1. Based on ability of drug to kill cancer cells; normal cells may also be damaged, producing side effects discussed below. Effect is greatest on rapidly dividing cells, such as bone marrow cells, the GI tract and hair.
2. Different drugs act on tumor cells in different stages of the cell growth cycle.

Types of Chemotherapeutic Drugs

1. Antimetabolites: foster cancer cell death by interfering with cellular metabolic process.
2. Alkylating agents: act with DNA to hinder cell growth and division.
3. Plant alkaloids: obtained from the periwinkle plant; makes the host's body a less favorable environment for the growth of cancer cells.
4. Antitumor antibiotics: affect RNA to make environment less favorable for cancer growth.
5. Steroids and sex hormones: alter the endocrine environment to make it less conducive to growth of cancer cells.

Case Study
Ms. Linda Levin is a 48-year-old accountant diagnosed with breast cancer. Ms. Levin is starting cyclophosphamide (Cytoxan) therapy in combination with another antineoplastic agent. This is Ms. Levin's first experience with chemotherapy.

Prototype--Cyclophosphamide (Cytoxan)

1. Action. Produces cytoxic effects by damaging DNA and interfering with cell replication. Most effective against rapidly dividing cells.
2. Use. Leukemias; multiple myeloma; neuroblastoma; ovarian, breast, lung cancers; Hodgkin's disease; Ewing's sarcoma.
3. Adverse Effects. Gonadal suppression, hemorrhagic and nonhemorrhagic cystitis.
4. Nursing Implications
1. Force fluids.
2. Assess for signs and symptoms of unexplained bleeding.
3. Assess leukocyte count frequently.
4. Monitor CBC, uric acid, electrolytes, thrombocytes, and hepatic and renal function at least twice a week.
5. Instruct client to report hematuria or dysuria immediately.

TABLE 2.25 Alkylating Agents

Major Side Effects and Nursing Interventions

1. GI system
1. Nausea and vomiting
1. Administer antiemetics routinely every 4-6 hours as well as prophylactically before chemotherapy is initiated.
2. Withhold foods/fluids 4-6 hours before chemotherapy.
3. Provide bland foods in small amounts after treatments.
2. Diarrhea
1. Administer antidiarrheals.
2. Maintain good perineal care.
3. Give clear liquids as tolerated.
4. Monitor potassium, sodium, and chloride levels.
3. Stomatitis
1. Provide and teach the client good oral hygiene, including avoidance of commercial mouthwashes.
2. Rinse with viscous lidocaine before meals to provide an analgesic effect.
3. Perform a cleansing rinse with plain water or dilute a water-soluble lubricant such as hydrogen peroxide after meals.
4. Apply water-soluble lubricant such as K-Y jelly to lubricate cracked lips.
5. Advise client to suck on Popsicles to provide moisture.
2. Hematologic system
1. Thrombocytopenia
1. Teach client the importance of avoiding bumping or bruising the skin.
2. Protect client from physical injury.
3. Avoid aspirin or aspirin products.
4. Avoid giving IM injections.
5. Monitor blood counts carefully.
6. Assess for and teach signs of increased bleeding tendencies (epistaxis, petechiae, ecchymoses).
2. Leukopenia
1. Use careful handwashing technique.
2. Maintain reverse isolation if white blood cell count drops below 1000/mm³.
3. Assess for signs of respiratory infection.
4. Instruct client to avoid crowds/persons with known infection.
3. Anemia
1. Provide for adequate rest periods.
2. Monitor hemoglobin and hematocrit.
3. Protect client from injury.
4. Administer oxygen as necessary.
3. Integumentary system--Alopecia
1. Explain that hair loss is not permanent.
2. Offer support and encouragement.
3. Scalp tourniquets or scalp hypothermia via ice pack may be ordered to minimize hair loss with some agents.
4. Advise client to obtain a wig before initiating treatments.
4. Renal System
1. May cause direct damage to kidney by excretion of metabolites; encourage fluids and frequent voiding to prevent accumulation of metabolites in bladder.
2. Increased excretion of uric acid may damage kidneys.
3. Administer allopurinol (Zyloprim) as ordered to prevent uric acid formation; encourage fluids when administering allopurinol.
5. Reproductive System
1. Damage may occur to both men and women resulting in infertility and/or mutagenic damage to chromosomes.
2. Banking sperm often recommended for men before chemotherapy.
3. Patients and partners advised to use reliable methods of contraception during chemotherapy.
6. Neurologic System
1. Plant alkaloids (vincristine) cause neurologic damage with repeated doses.
2. Peripheral neuropathies, hearing loss, loss of deep tendon reflexes, and paralytic ileus may occur.

Radiation Therapy


Principles

1. Radiation therapy uses ionizing radiation to kill or limit the growth of cancer cells, may be internal or external.
2. It not only injures the cell membrane, but destroys or alters DNA so that the cells cannot reproduce.
3. Like chemotherapy, effect cannot be limited to cancer cells only; all exposed cells, including normal ones, will be injured, causing side effects discussed below. Localized effects are related to area of body being treated; generalized effects may be related to cellular breakdown products.
4. Types of energy emitted
1. Alpha: particles cannot pass through skin, rarely used
2. Beta: particles cannot pass through skin, somewhat more penetrating than alpha, generally emitted from radioactive isotopes, used for internal source
3. Gamma rays (electromagnetic or x-rays): penetrate deeper areas of body, most common form of external radiotherapy.

Methods of Delivery

1. External radiation therapy: beams high-energy rays directly to the affected area.
2. Internal radiation therapy: radioactive material is injected or implanted in the client's body for a designated period of time.
1. Sealed implants: a radioisotope enclosed in a container so it does not circulate in the body; client's body fluids should not become contaminated with radiation.
2. Unsealed sources: a radioisotope that is not encased in a container and does circulate in the body and contaminate body fluids.

Factors Controlling Exposure

1. Half-life: time required for half of radioactive atoms to decay
1. Each radioisotope has a different half-life.
2. At the end of the half-life, the danger from exposure decreases.
2. Time: the shorter the duration, the less the exposure
3. Distance: the greater the distance from the radiation source the less the exposure
4. Shielding: all radiation can be blocked; rubber gloves stop alpha and usually beta rays; thick lead or concrete stops gamma rays
5. These factors affect health care worker's exposure as well as client's.
1. Health care worker at greater risk from internal than external sources
2. Film badge can measure the amount of exposure received
3. No pregnant nurses or visitors permitted near radiation source

Side Effects of Radiation Therapy and Nursing Interventions

1. Skin: itching, redness, burning, oozing, sloughing
1. Keep skin free from foreign substances.
2. Avoid use of medicated solutions, ointments, or powders that contain heavy metals such as zinc oxide.
3. Avoid pressure, trauma, infection to skin; use bed cradle.
4. Wash affected areas with plain water and pat dry; avoid soap.
5. Use cornstarch, olive oil for itching; avoid talcum powder.
6. If sloughing occurs, use a sterile dressing with micropore tape.
7. Teach client to avoid exposing skin to heat, cold, or sunlight and to avoid constricting or irritating clothing.
2. Anorexia, nausea, and vomiting
1. Arrange mealtimes so they do not directly precede or follow therapy.
2. Encourage bland foods.
3. Provide small, attractive meals.
4. Avoid extremes of temperature.
5. Administer antiemetics as ordered before meals.
3. Diarrhea
1. Encourage low-residue, bland, high-protein foods.
2. Administer antidiarrheal drugs as ordered.
3. Provide good perineal care.
4. Monitor electrolytes, particularly sodium, potassium, and chloride.
4. Anemia, leukopenia, and thrombocytopenia
1. Isolate from those with known infections.
2. Provide frequent rest periods.
3. Encourage high-protein diet.
4. Instruct client to avoid injury.
5. Assess for bleeding.
6. Monitor CBC, leukocytes, and platelets.

Bone Marrow Transplant

1. General information
1. Treatment alternative for a variety of diseases
1. Malignancies including several types of leukemias
2. Blood disorders including severe aplastic anemia, thalassemia
3. Solid tumors such as breast cancer and brain tumors; treatment for these diseases frequently causes bone marrow destruction; autologous bone marrow transplant may be indicated (Bone marrow harvested before chemotherapy or radiation destroys it and infused after therapy completed)
4. Other conditions including malignant infantile osteopetrosis, some inherited metabolic disorders
2. Types
1. Autologous: client transplant with own harvested marrow
2. Syngeneic: transplant between identical twins
3. Allogeneic: transplant from a genetically nonidentical donor
1. most common transplant type
2. sibling most common donor
3. Procedure
1. Donor suitability determined through tissue antigen typing; includes human leukocyte antigen (HLA) and mixed leukocyte culture (MLC) typing.
2. Donor bone marrow is aspirated from multiple sites along the iliac crests under general anesthesia.
3. Donor marrow is infused IV into the recipient.
4. Early evidence of engraftment seen during the second week posttransplant; hematologic reconstitution takes 4-6 weeks; immunologic reconstitution takes months.
5. Hospitalization of 2 or 3 months required.
6. Prognosis is highly variable depending on indication for use.
2. Complications
1. Failure of engraftment
2. Infection: highest risk in first 3-4 weeks
3. Pneumonia: nonbacterial or interstitial pneumonias are principal cause of death during first 3 months posttransplant
4. Graft vs host disease (GVHD): principal complication; caused by an immunologic reaction of engrafted lymphoid cells against the tissues of the recipient
1. Acute GVHD: develops within first 100 days posttransplant and affects skin, gut, liver, marrow, and lymphoid tissue
2. Chronic GVHD: develops 100-400 days post-transplant; manifested by multiorgan involvement
5. Recurrent malignancy
6. Late complications such as cataracts, endocrine abnormalities
3. Nursing care: pretransplant
1. Recipient immunosuppression attained with total body irradiation (TBI) and chemotherapy to eradicate existing disease and create space in host marrow to allow transplanted cells to grow.
2. Provide protected environment.
1. Client should be in a laminar air flow room or on strict reverse isolation; surveillance cultures done twice a week.
2. Objects must be sterilized before being brought into the room.
3. When working with children introduce new people where they can be seen, but outside child's room so child can see what they look like without isolation garb.
3. Monitor central lines frequently; check patency and observe for signs of infection (fever, redness around site).
4. Provide care for the client receiving chemotherapy and radiation therapy to induce immunosuppression.
1. Administer chemotherapy as ordered, assist with radiation therapy if required.
2. Monitor side effects and keep client as comfortable as possible.
3. Monitor carefully for potential infection.
4. Client will become very ill; prepare client and family.
4. Nursing care: posttransplant
1. Prevent infection.
1. Maintain protective environment.
2. Administer antibiotics as ordered.
3. Assess all mucous membranes, wounds, catheter sites for swelling, redness, tenderness, pain.
4. Monitor vital signs frequently (every 1-4 hours as needed).
5. Collect specimens for cultures as needed and twice a week.
6. Change IV set-ups every 24 hours.
2. Provide mouth care for stomatitis and mucositis (severe mucositis develops about 5 days after irradiation).
1. Note tissue sloughing, bleeding, changes in color.
2. Provide mouth rinses, viscous lidocaine, and antibiotic rinses.
3. Do not use lemon and glycerin swabs.
4. Administer parenteral narcotics as ordered if necessary to control pain.
5. Provide care every 2 hours or as needed.
3. Provide skin care: skin breakdown may result from profuse diarrhea from the TBI.
4. Monitor carefully for bleeding.
1. Check for occult blood in emesis and stools.
2. Observe for easy bruising, petechiae on skin, mucous membranes.
3. Monitor changes in vital signs.
4. Check platelet count daily.
5. Replace blood products as ordered (all blood products should be irradiated).
5. Maintain fluid and electrolyte balance and promote nutrition.
1. Measure I&O carefully.
2. Provide adequate fluid, protein, and caloric intake.
3. Weigh daily.
4. Administer fluid replacement as ordered.
5. Monitor hydration status: check skin turgor, moisture of mucous membranes, urine output.
6. Check electrolytes daily.
7. Check urine for glucose, ketones, protein.
8. Administer antidiarrheal agents as needed.
6. Provide client teaching and discharge planning concerning
1. Home environment (e.g., cleaning, pets, visitors)
2. Diet modifications
3. Medication regimen: schedule, dosages, effects, and side effects
4. Communicable diseases and immunizations
5. Daily hygiene and skin care
6. Fever
7. Activity