Cancer Flashcards
What are the hallmarks of cancerous cells
Self-sufficient in growth signals Insensitivity to anti-growth signals Tumour invasion and metastasis Lack of immune rejection Evading apoptosis Angiogenesis Limitless replication/uncontrolled proliferation
Describe a benign tumour
Can progress to cancer
Well encapsulated
Cells and Tissues appear normal
Do not spread to lymph nodes or distant location
Describe a malignant tumour
Rapid growth rates
Altered microscopic appearance
—->loss of cell differentiation
—->Absence of normal tissue organisation
Not encapsulated
Invades blood vessels, lymphatics and surrounding structures
Distant metastases
What are the 3 types of skin cancer
Basal Cell Carcinoma
Squamous Cell Carcinoma
Melanoma
What are the cells affected, characteristics and treatment options in Basal Cell Carcinoma
Arises from the stem cells in the basal layer of the epidermis or hair follicles
Slow growing and rarely spreads
Appears as a pearly lump or scaly, dry area that’s either shiny + pale or bright + pink
Treatment is guided by the stage and progression and includes Topical creams (Imiquimod), Surgical excision with 4mm - 5mm border, phototherapy, curettage + diathermy
What are the cells affected, characteristics and treatment options in Squamous Cell Carcinoma
Arises from Keratinocytes in the outer layers of the epidermis.
Rapidly growing lump that appears as a sore that’s not healed and may be painful to touch
Appears as a thickened red, scaly spot
Treatment is guided by the stage and progression and includes Surgical excision, Radiotherapy and/or Chemotherapy, curettage and diathermy.
What are the cells affected, characteristics and treatment options in Melanoma
Arises from the Melanocytes of the epidermis.
Differ in size, shape and colour and has irregular borders
Appears brown, black, blue or red.
May itch or bleed.
Treatment requires wide surgical excision due to the penetrating nature of the lesion.
The risk of sentinel node involvement increases with lesions >1mm thick.
—-> biopsy recommended
If +ve, lymphectomy, Chemotherapy and Radiotherapy are recommended
What is the relationship between sun exposure and skin cancer
The sun emits UVA and UVB rays which are absorbed by the skin and damage cell structures.
UVB is directly absorbed by DNA and causes change in a number of genes
UVA damages DNA by generating oxygen radicals that cause DNA molecules to break.
The changes seen in these genes, particulary ‘Tumour suppressor gene’ can decrease cell repair and induce uncontrolled cell proliferation.
Define Angiogenesis and relate to tumour formation
The formation of new blood vessels.
Due to rapid growth and proliferation, tumours secrete endothelial growth factor to stimulate angiogenesis.
This increase blood and nutrient supply to the tumour
Define Metastases and relate to tumour formation
The spread of cancer cells from the site of original tumour (primary tumour)
Cancer cells can spread through the vascular and lymphatic pathways, as well as through the tissues.
Common metastases sites include the liver, bone, lungs and brain. It is though that specific interactions between the cancer cells and tissue receptors influence where metastasis will occur
Why are some cancers more prevalent in older people
Some cancers take several years to develop and become symptomatic, so are not diagnosed til older age.
Also, at later stage in life the human cells have cumulative exposure to carcinogens, environmental and genetic influences that promote the development of cancer.
What are the common VIRAL causes of cancer
Common viral causes of cancer include Hepatitis B/C affecting the liver, Human Papilloma Virus affecting the cervix, and Epstein-Barr virus related to lymphoma and nasopharyngeal cancer.
What factors are relevant in the risk of developing cancer
lifestyle:
Cigarette smoking containing carcinogens
Western diet high in fat, sugar, salt red meat and low in fibre.
Abdominal Obesity, highly metabolically active and release free fatty acids within visceral organs
Environmental:
Pollutants and exposure to UVA/UVB rays
Electromagentic fields r/t mobile phone towers and mobile phone use
Occupational:
Carcinogen exposure such as asbestos, toxic chemical and smoke
Genetic:
Family history of cancers
Inherited altered genes such as the BRCA 1/2, p53
Mutations to oncogenes, tumour suppression genes and DNA repair genes.
How may diet and physical activity assist in preventing cancer
Physical activity reduces risk factors by increasing gut motility which decreases time the GI lining is exposed to potential carcinogens. Also reduces insulin and sex hormones (oestrogen and androgens) which in turn decreases exposure of these to breast tissue
High fibre diet promotes gut motility. Antioxidants can protect the DNA against damage. Various fruit and veg have protective substances against cancer
Discuss the clinical manifestations of pain, fatigue and cachexia in relation to cancer development
Early stages of cancer development may be asymptomatic. Pain may be attributed to compression, obstruction, inflammation, tearing or stretching of tissue or adjacent structures. Bone metastases cause referred pain in other bones and joints
Persistent tiredness is related to physiological impact of the cancer itself and/or cancer treatments. Fatigue is influenced by sleep disturbances, changes in chemical concentrations, psychosocial factors, physical activity levels, dietary/nutritional status. It is a subjective and highly individualised phenomenon.
Cachexia is severe tissue wasting and emacication. Fat stores and muscle loss occurs and the body appears excessively thin. Attributed to taste changes, early satiety, side effects of treatments and a hypermetabolic state.
Discuss the incidence of cancers across the lifespan
Cancer is more prevalent in the older adult
Leukaemia is the most common cancer in both male and female children
Testicular cancer and melanoma is seen in teenage males
Melanoma is seen in teenage females
Throughout early adulthood melanoma remains prevalent in both sexes
Breast cancer is seen in late adult females
Prostate cancer is seen in late adult to older adult males
Colorectal cancer is seen in older adult females
Describe the 3 key events involved in Carcinogenesis
INITIATION - the initial event when the cell is exposed to the carcinogen
PROMOTION - a secondary event when the cell is exposed to additional factors that promote growth of the transformed cells
PROGRESSION - the 3rd stage when the cellular changes become irreversible and express malignant characteristics
What is Apoptosis and why is it necessary
Apoptosis occurs when cell growth is excessive to ensure all abnormal cells are destroyed
What is a cytokine
Chemical signals released by immune cells to signal between immune system processes
Identify 2 cytokines associated with the body’s response to cancer
Interleukin - 1 from macrophages to induce the inflammatory response
Tumour necrosis factor - alpha from macrophages which is toxic to tumour cells
What does the TNM cancer staging system do
TNM characterises the extent of a tumour, whether or not regional lymph nodes are involved and evidence of metastases
Assist in predicting prognosis, determines treatment and continuity of information between patient and MDT
Define the elements of the TNM acronym and describe the 5, less detailed categories used to assign an overall stage of cancer
T - (TUMOUR) defines tumour size
The number allocated = size of tumour and it’s local extent. Number varies according to site
N - (NODES) involvement of lymphatic nodes
Lymph node involvement, the higher number = more nodes are involved
M - (METASTASES) degree (if any) of metastases
Number allocated correlated to extent of distant metastases
Stage 0 - (carcinoma insitu) abnormal cells present but have not spread to nearby tissue
Stage 1 - (Localised) confined to the organ of origin
Stage 2 - (Localised) locally invasive
Stage 3 - (Regional) spread to regional structures, such as lymph nodes
Stage 4 - (Distant) metastasised to distant sites
What factors need to be considered when determining cancer treatment
The type and extent of the cancer
The preference of the patient
The treatments available/Accessible
The clinical status of the patient (are they fit enough to tolerate treatment)
The adverse effects of treatments
The necessity of freezing eggs/sperm prior to commencement
The chance of infection. anaemia and thrombocytopaenia
What 5 factors predispose individuals with cancer to infection
Age - as many cancers occur at older age and the immune system diminishes as we age, risk of infection increases
Tumour - secrete factors leading to nutritional derangement’s or sites and circumstances favourable to growth of micro-organisms
Leukaemias - Agranulocytosis, impaired phagocytosis leads to bleeding or break in skin integrity
Lymphomas - Resultant humoral and cellular immune defects from altered immunoglobulin production
Treatments - Chemotherapy, Radiation disturb immune cell proliferation and function. Surgery breaks first line defence
Discuss the factors that contribute to anaemia in cancer patients
Chronic bleeding or haemorrhage leads to RBC loss quicker than can be replaced
Reduced hormonal precursor secretion (erythropoietin) for RBC production
Defective RBC production which have a shorte life span
Tumour or Treatments directly impair the bone marrows ability to produce RBCs
Impaired iron absorption and utilisation
Autoimmune responses attack RBCs leading to Thrombocytopaenia
What is the “Cell-Kill Fraction”
the tendency of a drug to kill a constant proportion, rather than a certain number of cancer cells, when given in adequate doses
What is “Growth Fraction”
refers to the cells in a tumour which are actively engaged in cell cycling, from those that are not
Define radiopharmaceuticals
a form of radiotherapy whereby these drugs containing radioactive isotopes that damage cells by emitting ionising rays
List 2 radioactive drugs
Radio active Iodide: used to treat hyperthyroidism and thyroid carcinoma as the drug accumulates in thyroid tissue
Samarium-153: used to relieve bone pain in osteoblastic cancer metastases. The Beta and Gamma rays emitted concentrate in areas of high bone turnover
Describe the difference between radiation therapy and chemotherapy in cancer treatment
Radiation uses x-rays or ionising radiotherapy to damage cancer cell DNA and components of the micro-environment. Whereas Chemotherapy agents are non-selective cytotoxic drugs that target vital cellular or metabolic processes present in both malignant and normal cells.
Different cytotoxic drugs target different phases of the cell growth and cell cycle. This attributes for the side effects seen in chemotherapy treatment as it targets these non-malignant cells.
- hair and skin
Discuss combination therapy and the 3 underlying principles
The use of 2 or more anti-cancer drugs at the same time that produce synergistic therapeutic effect with less resistance to treatment.
Treatment regime consists of a 2-3 week period of chemotherapy on various days, followed by a drug-free period to allow WBCs to recover.
3 principles:
Each drug when used alone should be active against the specific cancer
Drugs should have different mechanisms of action
Drugs should have different organ toxicities OR if similar, have different rates of toxicity after administration
Define and identify 1 Antimetabolite
Antimetabolite contain false building blocks that interfere with DNA production
examples: Fluorouracil, Methotrexate
Define and identify 1 Alkylating agent
Alkylating agents prevent cell division by cross-linking between strands of DNA
examples: Cyclophosphamide, Lomustine, Dacarbazine
Define and identify 1 Antitumour Antibiotics
Antitumour antibiotics interfere with DNA functioning by blocking transcription of DNA to RNA
examples: Bleomycin, Dactinomycin
Define and identify 1 mitotic inhibitor
Mitotic inhibitors block cell division in metaphase
examples: Vincristine, Paclitaxel
Identify the Dose, Mechanism of action and indication in cancer treatment of METOCLOPRAMIDE
10mg TDS PO/IVI
Blocks Dopamine receptors in the Chemo Trigger Zone
Prophylactic and active treatment agains N + V in chemotherapy
Identify the Dose, Mechanism of action and indication in cancer treatment of DEXAMETHASONE
0.5mg - 16mg Daily PO
Inhibits prostaglandin synthesis and reduces 5HT turnover (serotonin)
Used alone or adjunct in prophylaxis or treat of cancer treatment associated N + V
Long acting
Identify the Dose, Mechanism of action and indication in cancer treatment of ONDANSETRON
PO - 8mg - 24mg 30 minutes before treatment
IVI - 0.15mg/kg max dose 16mg
Blocks 5HT-3 (serotonin) receptors in the GI tract, CTZ and vomiting centres
Used alone or adjunct in prophylaxis or treat of cancer treatment associated N + V
Identify the Dose, Mechanism of action and indication in cancer treatment of CALCIUM FOLINATE
Variable dose administered a few hours after chemotherapy
Enhances toxicity of FLUOROUCIL, Substitutes Folic Acid and helps prevent bone marrow toxicity
Identify the Dose, Mechanism of action and indication in cancer treatment of PELIFERMAN
IV Bolus 3 days after end of treatment
Targets and binds to KGF receptors to stimulate epithelial cell proliferation, differentiation and upregulation.
Reduces manifestations of Oral Mucositis and enhances healing of Mucosal ulcers r/t treatment
Identify the Dose, Mechanism of action and indication in cancer treatment of OXYCODONE
PO 15mg - 20mg SC 2.5mg - 10mg IV 0.5mg - 2mg PR 30MG Opioid agonist analgesic Relief of moderate to severe pain
Identify the Dose, Mechanism of action and indication in cancer treatment of HYDROMORPHONE
IM/SC 1.3mg - 2mg
PO 6.5 - 7.5mg
Semi-synthetic opioid agonist with faster onset and shorter duration of action than MORPHINE
Relief of moderate to severe pain
What are the common BACTERIAL causes of cancer
Helicobacter pylori infection of the stomach
