Oncology basics Flashcards
What is carcinogenesis?
Transformation of normal cells to neoplastic cells through permanent genetic alterations
or mutations
Oncogenesis - benign and malignant tumours that occurs in a multistep process
What are carcinogens?
Agents known/suspected to cause tumours
Carcinogenic - cancer causing
Oncogenic - tumour causing
Examples:
- Chemical (e.g. from cigarettes, asbestos)
- Viral (e.g. HPV)
- Ionising + non-ionising radiation (e.g. exposure to UVA and UVB)
- Hormones (e.g. oestrogen)
- Parasites, mycotoxins
- Constitutional factors e.g. race, age, sex, diet, premalignant conditions (e.g. IBD), transplacental exposure
What are the features of a benign tumour?
Often resemble tissue they’ve arisen from
Localised and non invasive
Slow growth rate, low mitotic activity, necrosis rare
Encapsulated
Possible issues:
- Pressure on adjacent structures or obstruction of flow
- Can produce hormones - and as autonomous, excess will be produced and unregulated
- Can transform to malignant neoplasms
- Anxiety
What are the features of a malignant tumour?
Diverging from the initial tissue due to genetic changes - variable resemblance to normal tissue
Invasive
Rapid growth rates, mitotic figures, poorly defined/irregular borders, necrosis common
Possible issues:
- Destruction of adjacent tissue
- Metastases
- Blood loss from ulcers
- Obstruction of flow
- Hormone production
- Paraneoplastic effects i.e.proteins produced by the tumours, other effects of the tumour
- Anxiety and pain
What are some different words to differentiate tumours?
‘Oma’ = a neoplasm
Prefix = behavioural and cell type classificatione.g.
- Papilloma= benign tumour of non-glandular epithelium
- Adenoma= benign tumour of glandular or secretory epithelium
Prefix with type of origin e.g. - Thyroid adenoma
Benign connective tissue neoplasms e.g.
- Lipoma - adipocytes
- Chondroma - cartilage
- Osteoma - bone
- Angioma - vascular
- Rhabdomyoma- striated muscle
- Leiomyoma - smooth muscle
- Neuroma - nerves
Carcinoma= Malignant tumour(neoplasm) of epithelial cells
- Prefix with epithelial cell type ie transitional cell carcinoma
Malignant tumour of connective tissue=
Change’oma’to sarcoma e.g. osteosarcoma = cancer of the bone
Where cell origin is unknown, called anaplastic
Not all’omas’are neoplasms:
- Granuloma
- Mycetoma
- Tuberculoma
Not all malignant tumours are carcinoma or sarcoma:
- Melanoma - malignant neoplasm of melanocytes
- Mesothelioma - malignant tumour of mesothelioma cells
- Lymphoma - malignant neoplasm of lymphoid tissue
Lots of cancers have eponymous names:
- Burkittslymphoma
- Ewing’s sarcoma
- Grawitztumour
- Kaposi’s sarcoma
What are the most common cancers?
General: Breast Prostate Lung Bowel
Men:
Prostate, lung, bowel
Women:
Breast, lung, bowel
1/2 people will get cancer in their lifetime
What are the most common cancers that metastasise to bone?
Breast Lung Kidney Thyroid Prostate
(5 B’s of bone mets - Breast, Bronchus, B-idney, B-hyroid - B-rostate, stupid mnemonic but it works)
(They all can cause malignant hypercalcaemia, though prostate does this more rarely because of how it metastasises to bone)
What are the most common cancers that metastasise to the brain?
Lung Breast Skin (melanoma) Colon Kidney Thyroid
What are the most common cancers that metastasise to the liver?
Breast Bowel Lung Pancreatic Stomach Ovarian
Neuroendocrine tumour (NET)
What are the most common cancers that metastasise to the lungs?
Breast Bowel Kidney Testicular Bladder Melanoma skin Bone Soft tissue sarcomas Head and neck
