Oncology Flashcards
Onco =
Tumour
Neoplasm =
New growth
Mass of tissue growing faster & uncontrolled manner
Tumour =
‘Swelling’
Now mass / growth of tissue
Either benign or malignant
No longer responds to normal growth factors, faster & uncontrolled
Benign =
Non-cancerous growth
Still excesseive but no metastasis
Grows slowly
Non life-threatening but can damage due to compression of space
Malignant =
Cancerous growth
Excesseive & uncontrolled & faster
Metastasise, often systemic & life-threatening
Undifferentiated, non-functional cells with varied shape&size nuclei, not encapsulated/loosely bound
Why is oncology so important & prevalent
Second leading cause of death in works - 9 million a year
Predicted to double by 2030
Most common causes: lung, liver, colorectal, stomach & breast
More developed countries have higher cancer rates - emphasising link to environment, lifestyle, diet, meds, drugs
Mitosis is
Growth & repair of somatic cells
All cells differentiated & specialised
Some cells so much they cannot undergo mitosis
Mitosis - how malignant tumours grow
Meiosis is
Growth & reproduction of sex cells (gametes)
Differentiated & specialised
How do malignant tumours grow
Via mitosis
Uncontrollable manner, loses specialised function & become disorganised
Cell architecture key to observe in suspected neoplastic growth
% of cases of inherited cancer
5-10%
What is cancer
A result of genetic mutations
Result of an UNDERLYING CAUSE - which ultimately promote mutations of multiple genes
Essential to explore interaction of patients genes with environment
What is a proto-oncogene
A gene that Causes mitosis
Growth of a tissue
Inactivated by
Tumour suppression genes
What is an oncogene
Tumour suppresion genes & proto-oncogenes mutations = New genes that cause overproduction of growth factors & increased cell division uncontrolled
(Divide uncontrolled & rapid)
Malignant cells can only grow 1-2mm3 without a blood supply
What is angiogenesis
Angio = vessel
Manufacture more blood vessels to creat a blood supply
What environment promotes cancerous cell growth
- Acidic environment
- Anaerobic environment
- Glucose rich
What are malignant cells dependent upon
Glucose for their own metabolism
Have many more glucose receptors on their membrane
What is contact inhibition
Proteins produced by normal cells that prevent cells dividing beyond available space
What process do cancerous cells lose
Contact inhibition
Causing uncontrolled growth
What is a mutation
Change in genetic information
Disruption to DNA sequence/number/“recipe”
Promoting abnormal growth
What is a mutagen
Agent that changes genetic information
& disrupt normal growth
Such as:
Environmental hazards
Chemicals (environmental, household, drugs, vaccines)
Radiation (x-rays, microwave, mobiles)
Viruses
Inflammation
Defective immunity
Stress/trauma
What is a carcingogen
Any cancer causing agent
Nitrosamines, heavy metals, asbestos, X-rays, UV-rays
What is carcinogenesis
The process by which normal cells are transformed into cancer cells
5-10% inherited genetic defects
90-95% attributed to environment & lifestyle
Some tumours can take 20-40 years
Environmental & lifestyle cancer risk factors
- 5-10% genetic predisposition
- chronic inflammation
- chronic stress
- chronic immunodeficiency
- radiation
- smoking
- GIT dysfunction, liver & intestines
- drugs & cosmetics
- vit D deficiencies & thyroid disorders (requires iodine)
- sexual behaviour
- excessive sunlight exposure
- metal toxins
- vax ingredients
What gene represents breast cancer susceptibility
BRCA
Why are parabens harmful
Have been found in breast tumours, can also mimic oestrogen hormone leading to oestrogen-driven cancers
Why can chronic stress increase cancer risk
Suppress immune system
Increase cortisol & sympathetic NS
Anaerobic environment forms which leads to acidity
MHC-I antigen illustrates if damaged cell inside
What virus has been linked to cervical cancer
HPV
Human papilloma virus
How does obesity increase cancer risk
Excess body fat changes hormone metabolism»_space; higher oestrogen»_space; drives oestrogen+ thmours
Breast cancer is linked to post-menopausal women
Dietary risk factors for cancer
- pro-inflammatory
- red meats, charcoal/smoked/burnt
- n-nitroso compounds in cured meats
- excess alcohol
- low fibre diet
- refined sugars
- dairy
What are acrymalides
Carcinogenic compounds produced by burning food
Why is dairy increase cancer risk
Pro-inflamm
Contains IGFs that promote tumour growth
Hormones added - is an endocrine disruptor
What is grading of tumours
Measure of degree of tumour cell differentiation/abnormality
Grade 1: similar to original cells, differentiated & specialised (benign)
Grade 4: undifferentiated/many abnormal cell sizes & shapes
What is cancer staging
Classification of malignant tumours extent
Helps to identify treatment approaches, disease progression & prognosis
Cancer stages 0-4
0: pre-cancerous
1: cancer limited to tissue origin
2: limited local spread of cancer cells
3: extensive local & regional spread
4: distant metastasis
What is TNM cancer staging
Tumour, Node, Metastases
T(1-4): size of primary tumour
N(0-3): degree of lymph node involvement
M(0-1): metastases
X = cannot be assessed
Local effects of cancer
- Damages ‘space’ occupies
- Can compress blood vessels leading necrosis of surrounding tissues & eventually its own leading to calcification (seen in Xray)
- metastasise
- pain occurs as later symptom by pressure or inflammation
- obstruction can occur in tubes/ducts
- tissue ulceration/inflammation may produce infection (especially in immunocompromised chemo/radiotherapy)
Systemic effects of cancer
- weight loss & cachexia (but can still have strong appetite)
- anaemia
- infection (pneumonia)
- para-neoplastic syndromes (secondary site symptoms)
Eg of para-neoplastic syndrome
Lung cancer tumour cells may produce ACTH (orother hormones) leading to cushing’s syndrome (excess cortisol)
Metastasis =
Spread of a malignant tumour usually via blood or lymph
Producing secondary tumours
Common sites of metastasis
Bone, liver, lung & brain
Due to rich blood supply
Key cancer presentation red flags
Anaemia, fatigue
Unexplained weight loss & cachexia
Night sweats
Unusual bleeding/discharge
Persistent indigestion/heartburn
Dysphagia
Change in bowel habits
Solid lump
Persistent cough/hoarseness
Swollen lymph nodes
Types of diagnostic testing for cancer
- Blood tests
- Tumour markers
- Imaging
- Biopsies
What is CEA
A glycoprotein tumour marker present within normal mucosal cells
Can be elevated in certain types of cancer, especially colorectal cancer
& ulcerative colitis, pancreatitis, liver cirrhosis
What is PSA tumour marker
Protein produced by prostatic cells
Present in small quantities in serum
May be elevated in presence of prostate cancer & other prostate disorders
Assists diagnosis & monitoring of tumour progression & metastasis but can produce false positives
What is hCG tumour marker
Should only be produced during pregnancy, males do not produce
Tests for cancer in testes, pancreas, pituitary, placenta
What is M2-PK tumour marker
Not organ-specific so can present in many types
Stool levels being investigated as a screening method for colorectal tumours
What is CA-125
Protein elevated in many cases ovarian cancer
Blood test ranges less than 35 U/mL
What is CA 15-3
Elevated in breast cancer
Blood ranges less than 30 U/mL
Main forms of allopathic cancer treatment
Combination or single
- surgery
- chemotherapy
- radiation
Aimed at removing/suppressing not treating cause - cancers often return !
What is palliative treatment
Care focuses on reducing symptoms severity rather than ‘curing’
Seen in late stages, preventing complications is vital
Focuses on quality of life!
Mastectomy =
Removal of breast
Prostatectomy =
Removal of the prostate gland with a very high rate of side effects!
Orchiectomy =
Removal of testes
What is fractionation
Dividing a dose of radiotherapy for cancer patients
What cells does radiotherapy target
Affects cells which divide most rapidly (both cancerous & healthy)
Causes loss of reproduction & induces apoptosis
External beam radiotherapy
Beams generated outside patient to target specific area
Internal beam radiotherapy aka brachytherapy
Probe inserted into body & releases within body cavity
Eg cervical or colorectal
System beam radiotherapy
Radioactive material enters body to reach cells all over body (very harmful)
What is chemotherapy
Chemical agents that enter the bloodstream & are destructive to malignant cells
Target rapidly dividing cells (cannot distinguish between normal & cancer)
Interfere with protein synthesis & DNA replication
Different drug combinations for different cancers
Radiotherapy & chemo adverse effects
- bone marrow depression = immunocompromised
- diarrhoea, bleeding, vomiting, nausea
- hair loss
- sterility
- organ damage & cancer (chemo)
What hormones are used for cancer treatment
- Oestrogens or anti-androgen drugs for prostate cancer
- tamoxifen to block oestrogen receptors = side effects (induces menopause)
- glucocorticosteroids (in lymphomas)
Type of biologic response modifiers for cancer treatment
Interferon
Analgesics for cancer treatment
opioid analgesics such as morphine (acts on CNS) to assist with symptomatic management (common in palliative)
Cancer prognosis
“Cure” for cancer is defined by orthodox medicine as a 5 year survival without reoccurrence
Cancer reoccurrence after this period is common
Several periods of remission can occur before cancer becomes terminal
Carcinomas =
Cancers which form in epithelial tissue lining
Skin, mouth, nose, throat, respiratory tract, lung, breast, prostate, stomach, intestines
Sarcomas =
Cancers which develop in connective tissue
Bone, cartilage, muscles, tendons
Leukaemias
Cancers which evolve in blood & bone marrow
Abnormal leukocytes produced travel throughout the bloodstream
Do NOT form solid tumours, but invade other cells
Lung cancer risks
Peak incidence between 60-70, men 3:1
90% due to smoking
Frequently follows COPD
Most commonly follows secondary tumour eg colorectal, osteosarcoma, prostate
Low prognosis 15%
Colorectal cancer risks
- Common >50yrs & developed countries
- Strong link with diet high in meat -(processed, smoked, excess salt), low fibre, lack of vitamin D
- Polyps
- Family history
Secondary complications of liver due to portal vein
Benign breast masses vs malignant
(90% benign)
Benign = pain/tenderness/mobile/smooth/regular borders
Malignant = asymptomatic, painless, unilateral fixed lump, overlying skin changes i.e dimpling, asymmetry of breasts, inverted & discharging nipple, enlarged lymph nodes
Breast cancer hormones roles
Breast cancer cells contain receptors that hormones or other proteins bind to & promote tumour growth
- receptors are most commonly for oestrogen (80% cases oestrogen dominant) as it builds & grows tissue
- progesterone receptors (65%)
- epidermal growth factor receptors (20%)
- tumour with no receptor types ‘triple negative’ more lethal (15%)
Breast cancer risk factors
- high oestrogen exposure increases risk i.e endogenous (excess formed within body) or exogenous (from outside eg contraceptive pill)
- longer reproductive life leading to higher oestrogen exposure
- BPA mimics oestrogen
- aluminium & parabens in antiperspirants (both been found in tumours)
- IGF1 in dairy
- BRCA 1&2 gene mutations - consider environment that promotes risk (only 5% total cases)
How does breast cancer thermography work
Safer & more effective to detect earlier changes
Cancer cells divide undergoing angiogenesis aka growing new blood vessels for own blood supply which gives off detectable heat
Ovarian cancer risks
- high oestrogen exposure (as in breast cancer risks)
- family history
- BRCA 1&2 gene mutations
- infertility/never birthed
- poor lifestyle: exercise, obesity, smokers
- diet rich in animal fats
- common >40
- most LETHAL gynaelogical malignancy
- talcum powder between legs
Cervical cancer risks
- persistent HPV infection (16+18 cause 70% cases)
- sexual behaviour (multiple partners)
- smoking, COCP
- most common cancer in young women 25-35
- 20% of all female cancers
What is malignant seeding in ovarian cancer
Spreading along peritoneum & can cause secondary cancer in bowel/colorectal
Gastric cancer risks
- diet rich in salted, pickled & smoked foods (N-nitroso compounds)
- male, smoking, age >55
- H pylori infection
- low fruit & veg
- highest rates in eastern asia (korea & japan)
Oesophageal cancer risks
- chronic irritation, alcohol, smoking
- GORD & Barretts oesophagus
(75% be obstructed before syMptoms present)
Pancreatic cancer risks
- poorly understood disease
- most arise from exocrine cells
- less common endocrine Islet cells (pancreatic neuroendocrine tumour): presents as glucose intolerance & insulin problems
- age >40, family history (germ line defects in 5-10%)
- smoking
- other health condition (diabetes, chronic pancreatitis, H pylori)
Prostate cancer risks
Obesity
High meat consumption (chargrilled), dairy, saturated fays, refined sugars
Increasing age >50yrs
Sexual abstinence
Bladder cancer risks
- Smoking (amines/hydrocarbons = carcinogens pooling in the bladder & inducing mutations)
- Chronic cystitis
- increasing age (70-80)
(Painless haematuria = red flag!)
Testicular cancer risks
Most common in young men 15-35
Higher risk if undescended testes & family history
