12 - cancer

chemotherapy goals

to kill cancer cells with limited injury to normal tissues

cure, control, or palliation (relieve pain)

chemotherapy barriers

not possible to know if 100% of cells are killed

limited dosing due to toxicity and damage to normal cells

drug resistance over time

solid tumours have low growth fraction

high tumor load hard to treat

strategies to help chemotherapry

intermittent therapy

• allow normal cells to grow between treatment

combination therapy

• reduce resistance, inc cancer cell kill, less toxicity to normal cells

dosing schedules

regional drug delivery

• localized delivery to decrease systemic effects

chemotherapy toxicities

myelosuppresion

• neutropenia, thrombocytopenia, anemia

GI dysfunction

• stomatitis, diarrhea, n/v

alopecia

• hair loss

reproductive toxicity

etraversion

• Iv therapy become interstital

carcinogensis

• can inmate or promote cancer

bone marrow suppression with chemotherapy

myelosuppression - chemo toxic to bone marrow due to tissue rapidly proliferating and active

reduce neutrophil, erthtrocytes and plateletes

risk for infection (low neutrophil) bleeding (low platelet) + anemia (low erythrocyte)

use hematopoietic growth factor for medh

hematopoietic growth factors

colony stimulating factors / biologic response modifiers - stimulate hematopoietic stem cells of bone marrow

• erythropoietic growth factors / erythropoietin - stem RBC production, rarely for cancer patients

• leukopoteic growth factors / filgrastim - neutrophil production stimulated

• thromboporietic growth factors - stimulate platelet prodcution

neutropenia

neutrophils below 500, life span 2-3 days - with cytotoxic drugs, neutropenia first happens

Nadir - lowest neutrophil count at day 10-14

at highest risk during nadir + risk from normal flora of body

neutrophils monitored carefully, hold chemotherapy until improve

• signs of infection, 38 C, pus, abscesses, infiltrates

nursing considération w neutropenia

educate infection + risk + avoiding others

38 C report immediately

hygiene

reverse isolation (protect patient)

avoid food w pathogen risk - meat, veggies, fruit

cultures on patient

filgarastrim (Neupogen)

leukoporietic growth factor therapy

identical to naturally occurring granulocyte colony stimul factor

elevates neutrophil count, acto n bone marrow

dec risk of injfection

caution with cancer originating in bone marrow

IV or SC

thrombocytoponea

low circulating platelets, inc risk of bleeding

common - bleeding gum and nose

monitor hematuria, gi bleed, hemoptysis (cough blood)

avoid meds that inc bleeding, vigour tooth brush, shaving, iv insert, avoid injections, overinflated bp - bruising

oprelevekin / neumega

thromboporietic growth factor therapy - identical to cytokine prod in bone marrow

stim platelet production, proliferation of hematopoietic stem cells and inc megakaryocytic synthesis (become platelets)

not for patients with myeloid cancers (bone marrow/blood cancer)

dec thrombocyopenia and dec need for platelet transfusion

SC

anemia

dec erythrocyte

less common than neutropenia and thrombocypotneia (long life span 120 days) - full recovery happen before levels go low

monitor signs of anemia - fatigue, pallor, SOB, HGB

o2 if needed

erythropoietin/ Epoetin alpha

ertyhopoeitic growth factor therapy - hormone, stimulate RBC production in bone marrow

not for patients with myeloid malignancies + leukemias (blood/bone marrow)

admin iv or SC

increases risk of stroke, HF, blood clot, MI, death

can accelerate tumour progression + shorten life in some patients

not for patients except palliative

stomatitis

inflamed oral mucous, 2-3days after chemo - continue up to more than 2 weeks

inflammation to ulcer, lead to infection

pain when eating, speaking, swallowing - weigh patient and intake

diarrhea with chem

destruction of epithelial lining - impaired absorption of nutrient, fluid lead to diarrhea

impair nutrition, hydration, lead to infection

nausea and vomitting with chemo

with chemotherapy due to stimulation of CTZ, immeidcatley with first dose and contiue for hours to days

• anticipatory emesis (prior), acute emesis (within treatment 24 Horus), delayed (1 day after to a few days

use antiemetics 30 min prior to chemo

aprepitatnt and dexamethasone and ondastron - high risk emesis comb

alopecia

hair loss, from injury to follicles because rapid proliferation

with many cytotoxic meds

7-10 days start of treatment, peak at 1-2 months

1-2 month after, reverse alopecia (grow back)

reproductive toxicity

cytoxitoc med interfere w early embryo development

fetal malformation, death (first trim common)

low risk after 18 weeks

irreversible sterility in men

affects ovaries - amenorrhea (no period) + menopausal symptom

extravasation

vesicants, highly reactive

admin via central line to lower risk of direct contact to tissues

extroversion - leakage / infliltration of drug (vesicant) from blood vessel to surrounding area, major tissue damage

pain, infection, loss of mobility, necrosis, sloughing

carcinogenesis

cytotoxic drugs damage DNA, promote cancer to develop, years after treatment

with alkylating agents comonly

type of anticancer cytotoxic drug / chemotherapry

cell cycle phase specific - toxic to cells passing through phases of cell cycle

• bc its cell phase specific, cannot target inactive cells in g0 phase

cell cycle phase nonspecific - act at any part of phase including g0

given in combination

doxorubicin

treats leukaemia, lymphoma and solid breast and ovarian tumours in adult and paediatric patients

cardiotoxicity - acute (arythmias last 2 weeks) or delayed and lead to HF

assess egg changes, chest pain, irregular HR, signs of HF, VS

paclitaxel

used in advanced ovarian cane,r breast cancer, non smalll cell lung cancer

cardiotoxitcity - acute (arthymias, Brady) or delayed HF

• ekg changes, chest pain, HR, vs, HF signs

neuropathy - autonomic nerve dysfunction, in 30-50% of people - contipaiton, urinary hesitancy

risk of severe hypersensitive reactions - hypotension, dynspea, hives, angioedema (rapid swelling skin, mucous, airways)

• consider glucocorticoid or histamine receptor antagonist

• monitor signs of hypersensitivity

vincristine

chemo for hematologic cancers (Hodgkin and non-hodghkin) - little effect on bone marrow

toxic to peripheral nerves, neuropathy - autonomic nerve dysfunction, in 30-50%. of people, constipation and urianry hesitancy

almost all patients experiences sensory or motor dyfynciton

minimal brain injury bc rarely enter CNS

assess reflex, sensory and motor nerve injruy

cisplatin

chemo - treat bladder, ovarian, testicular cancer

toxic to peripheral nerves

• assess reflex, sensory and motor nerve injury

major nephrotoxic properties - Renal damage and renal failure

assess I and o, serum cr, fluid overload, uremias,

• minimize renal damage with pre infusion iv hydration (also help with fluid loss due to vomitting)

highly emetic properties

ocular toxic and otoxic - vision and hearing loss

risk of severe hypersensitive reactions - hypotension, dynspea, hives, angioedema (rapid swelling skin, mucous, airways)

• consider glucocorticoid or histamine receptor antagonist

• monitor signs of hypersensitivity

cyclophosphamide

commonly used with combination to treat variety of ccancer

hard on bladder, lead to bladder injury - hemorrhagic cystitis - inflammation and bleeding of bladder lining

• assess urine output, hematuria, increase fluids

bleomycin

treats testicular cancer and Hodgkin lymphoma

canc cause severe injury to lungs in 10% patients

starts as pneuomintis (inflammation) progress to fibrosis or scarring, respiratory failure/death

• assess pulmonary function, CXR (chest X-ray), vital signs

tamoxifen

breast cancer hormonal therapy - anti estrogen

used for premenopausal women mainly

block estrogen receptor on breast cancer

• risk of endometrial cancer and thrombosis

• hot flash, fluid retention, menstrual irregularities, vaginal discharge, n/v

• not safe with pregnancy

oral, adjuvant therapy to suppress growth of cancer cells after surgery for years

longer treatment decrease reuccurance

not same toxicity as other chemotherapy agents

anastrozole

aromatase inhibitor

ONLY for post menopausal women - block production of estrogen from adrgenic precursors

does not block estrogen production from ovaries - why they dont benefit premenopausal women (they produce estrogen from ovaries)

• less hot flashes, weight gain, N/V

• no estrogen at all = no endometrial cancer or thromboembolic events

• musk pain, osteoperiois, fracture risk