Oncology Flashcards
1. Knowledge of oncology and nomenclature used 2. Familiar with various carcinogens associated with specific cancers 3. Knowledge of various cancer screening methods 4. Recall some of the clinical features of various common cancers 5. Have knowledge of signs and symptoms and classification of oral cancer 6. Knowledge of the role of radiotherapy, chemotherapy, palliative and terminal care in the management of patients with oral cancer
Define oncology
Study of tumours = an abnormal mass of tissue, the growth of which is autonomous and exceeds the normal rate of tissues and persists after cessation of the stimulus
They are classified as benign or malignant
What two components are found in all tumours
- Neoplastic cells (dividing uncontrollably)
2. Supporting stroma (connective tissue, blood vessels which provide the nutrients needed for growth)
What are carcinomas
Epithelial neoplasms
- squamous cell carcinoma
- adenocarcinoma
What are sarcomas
Mesenchymal neoplasms
- osteosarcoma
- liposarcoma
Outline malignant behaviour of tumours
- Altered differentiation and anaplasia (poor cellular differentiation and loss of morphology and orientation)
- Rate of growth increased
- Local invasion eg. OSCC invasion through basement membrane into underlying CT
- Metastases (distinguishes between malignant and benign)
Which malignant tumours do not metastasise
ALL malignant tumours metastasise except
- Brain tumours (as protected by BBB)
- Basal cell carcinomas (can sometimes metastasise)
How does the spread of tumours occur
Through
- Body cavities
- Lymphatics
- Blood vessels (haematogenous)
How do bone and soft tissue tumours spread
Bone and soft tissue tumours (SARCOMAS) spread through blood system
How do melanoma, breast, lung and gastrointestinal tumours spread
through lymphatic system
What is transcoelomic spread and which cancers typically do this
This is the uncommon spreading of cancer within cavity of the gut/chest and occurs with mesotheliomas and ovarian carcinomas
What chemical carcinogens can cause lung cancer and mesothelioma
- Aromatic hydrocarbons
- Asbestos
What chemical carcinogens can cause hepatocellular cancer
Aflatoxin-B1 (in decaying ground nuts)
What chemical carcinogens can cause gastric cancer
Nitrosamines and amides (food preservation salts)
What chemical carcinogens can cause bladder cancer
Azo dyes (Beta-napthylamine)
What chemical carcinogens can cause aplastic anaemia
- Alkylating agents = potent immunosuppressants e.g. Cyclophosphamide
How does ionising radiation cause cancer
- damages cellular genes resulting gene mutations
- natural radiation, nuclear power radiation and medical testing radiations are ionising and can cause cancer
- radiotherapy can also increase risk of further cancer development
What are the predisposing factors of BCC/SCC
- UV radiation (sun exposure in childhood)
- Skin type I/II (freckles and ginger hair)
- Arsenic
- Ionising radiation
- Burn/ vaccination scars
- Immunosuppression (azothiprine)
How does a BCC look
Small, shiny pink or pearly-white lump translucent/ waxy
Red, scaly patch with some brown or black pigment within the patch
How does a SCC look
Firm, red nodule due to fibrotic reaction occurring in the underlying tissue, it is a sore with a scaly crust that has rolled borders and central ulceration
Give an example of balanced translocation chromosome abnormalities predisposing patients to cancer
Philadelphia chromosome translocation from t(9;22) is associated with CML giving the fusion gene BCR/ABL with tyrosine kinase activity
Translocation from t(8;14) involving c-myc is indicated in Burkitt’s lymphoma