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
Give an example of point mutations predisposing patients to cancer
H-ras (Chemically induced changes indicative of bladder cancer)
Give an example of deletions causing predisposition to cancer
Deletion of tumour suppressor gene Rb on chromosome 13q 14 (Retinoblastoma)
What are the common symptoms of retinoblastoma
- Leucocoria
- Stabismus or squint
- Ocular inflammation
This cancer can cause loss of sight
Outline how HPV predisposes to cancer (DNA virus)
HPV 16/18 can cause squamous cell carcinoma of cervix and mouth
HPV 6/11 cause genital warts
What cancers can be a result of EBV (DNA virus)
- Burkitt’s lymphoma
- Nsaopharyngeal cancer
- B-cell lymphomas
What cancers can be a result of HBV (DNA virus)
Hepato-cellular carcinoma
What are the symptoms of lung cancer
- cough
- haemoptysis
- dyspnoea
- chest pain
- pneumonias (recurrent/slowly resolving)
- loss of appetite and weight loss
What are the signs of lung cancer
- cachexia
- clubbing
- anaemia
- HPOA (Hypertrophic pulmonary osteoarthropathy) = specific clubbing and pain in joints of small fingers
- lymphadenopathy (cervical)
- metastases (brain)
- complications e.g. bleeds and lung collapse
What is Horner’s syndrome (HPAM)
Disruption of post-ganglionic SNS fibres causing
- Partial Ptosis (paralysis of levator palpebrae superioris)
- Anydrosis (ipsilateral due to superior cervical ganglion damage)
- Meiosis (unopposed parasympathetic activity causing pupillary constriction)
- Enophthalmous
Resulting from: Damage to vascular lesions of cortex/brainstem, Cervical rib, Cancer of Lung, Thyroid, Oesophagus
What are the signs of colon cancer (both LHS + RHS)
- Abdominal mass on palpation
- Perforation (fluid within abdominal cavity may become infected)
- Haemorrhage
- Fistula (in long standing tumours e.g. epithelial drainage channel between colon and bladder is established, meaning there is faeces in the uric causing UTIs)
What are the signs of colon cancer (LHS only)
- Bleeding/ mucus production on pre-rectal examination
- Altered bowel habit
- Obstruction
- Tenesmus (feeling of incomplete bladder emptying)
- Mass on pre-rectal examination
What are the signs of colon cancer (RHS only)
- Reduced weight: cachexia
- Anaemia
- Abdominal pain
- Obstruction
What is Hodgkin’s lymphoma
An enlarged painless, contender, rubbery superficial lymphadenopathy which typically presents as cervical lymphadenopathy and causes fever, weight loss, night sweats, pruritus
It can be caused by Pel-Ebstein fever and has alcohol induced pain
There is lymph node enlargement and obstruction
Outline diagnostic features of malignant melanoma
- Increase in size
- Irregular shape outline
- Variation in colour
- Erythema at edge
- Crusting, oozing or bleeding
- Itching
What are the different types of biopsy that can be taken
- Excisions = complete lesion removed with margin
- Incisional = cross-section wedge when lesion is too large to excise
- Shave = superficial portion of dermis removed (benign)
- Punch = multiple biopsies taken for extensive sampling
What type of tumour is this marker indicative of :
Carcinoembryonic antigen (CEA)
Colon
Pancreas
Stomach
Breast
What type of tumour is this marker indicative of :
Alpha-feoprotein (AFP)
Liver
Testicular
Germ cell cancers
What type of tumour is this marker indicative of :
CA125
Ovarian cancer
What type of tumour is this marker indicative of :
Prostate specific antigen (PSA)
Prostate cancer
Where are the high risk areas for OSCC and why
Lateral sides of mouth and tongue
Floor of mouth
Lingual gingivae
This is because pooling of carcinogens can occur here
What are the risk factors of OSCC
- Age, Male
- Tobacco, alcohol, betel use (paan)
- Sun exposure (lip)
- Lichen Planus
- Ionising radiation
- Immunosuppression
- Low socioeconomic status
- Infection with HPV, Candida or syphilis
Outline oral effects of Betel chewing
- Occlusal tooth surface wear
- Betel chewer’s mucosa = born/red discolouration, tenacious quid particles, tendency to desquamation and peeling, epithelial hyperplasia and amorphous deposits of calcium granules
- Lichenoid reaction
- Oral precancerous lesions and malignancy: erythroleukoplakia, oral sub mucous fibrosis
List other malignant oral neoplasms
- Epithelial
- melanoma
- maxillary antra carcinoma
- glandular carcinoma
- intra-bony carcinoma - Sarcoma
- osteosarcoma
- rhabdomyosarcoma
- kaposi sarcoma - Secondary carcinomas
- within lymph nodes/ bone metastasis - Lymphoreticular neoplasms
- Lymphomas
What are the clinical features of OSCC
- Glandular ulcer with fissuring/ raised exophytic margins
- Red lesion (erythroplakia)
- White lesions (leukoplakia)
- Mixed red and white speckled lesions
- Indurated ulcer (fixed lesion to underlying tissue/ overlying skin mucosa)
- Lumps
What is the dental relevance of OSCC
- Non-healing extraction sockets
- Lymph node enlargement
- Pain/ numbness
- Loose tooth
- Dysphagia
- Weight loss
- Ear pain
Where are the common locations of OSCC
Lips, lateral border of tongue, floor of mouth
Buccal mucosa/ commissure region in paan or betel quid chewers
Reverse smokers may develop carcinoma of palate
What is the difference between non-neoplastic and neoplastic tumours
Neoplastic tumours continue proliferating after cessation of the stimulus that initiated change
What type of cancer can be caused by gene amplification
Neuroblastoma
What cancer can result form HTLV-1 (RNA virus)
Human T-cell Leukaemia Virus type-1 can cause Leukaemia and lymphoma
How can cancer biopsy be investigated
- Lesional biopsy
- Fine needle aspiration
- Imaging
Outline oral complications of radiotherapy
W1 = Nausea + vomitting W2 = Mucositis, taste changes W3 = Dry mouth < = Infections, caries, pulp pain/necrosis, tooth hypersensitivity, truisms, osteoradionecrosis, craniofacial defects
