Oncology I Flashcards
Define Oncology
Study of tumours
What is a tumour
An abnormal mass of tissue, the growth of which is virtually autonomous and exceeds that of normal tissues
What are the 2 components of all tumours
- Neoplastic cells
- Supporting storm i.e. CT , blod vessels
Give a few examples of benign tumours
Lipoma Fibroma Adenoma Leiomyoma Papillomas
What types of malignant tumours are there
Carcinomas - epithelial tissue
Sarcomas - mesenchymal tissues
Name some carcinomas and sarcomas
Carcinomas - oral squamous cell carcinoma, adenocarcinoma
Sarcomas - Osteosarcoma, Liposarcoma
How are malignant tumours differentiated from benign tumours
- Appearance (morphology)
Behaviour: - poor cellular differentiation and loss of morphology and orientation
- Rate of growth
- Local invasion e.g. OSCC invasion through basement membrane into underlying connective tissue
- Metastases (most important)
Which malignant tumours metastasise
All of them except for tumours of the brain and basal cell carcinomas (generally)
how can spread of tumours occur
- Body cavities
- Lymphatics
- Blood vessels
What kinds of tumour primarily spread through the blood system
Bone and soft tissue tumours (sarcomas)
What kinds of tumour usually spread through the lymphatic system
Melanoma, breast, lung and gastrointestinal
What are the most common forms of cancer
Lung cancer, breast cancer, colorectal cancer
Besides lung and colorectal cancers what is a very common cancer among men
Prostate
What are some environmental factors that contribute to carcinogenesis
- Chemicals
- Radiation
- Viruses
As a result of mutations in the genome of somatic cells
What can carcinogenic mutations in somatic cells cause to happen that can lead to malignant neoplasms
- Activation of growth-promoting oncogenes
- Alterations of genes that regulate apoptosis and DNA repair
- Inactivation of cancer suppressor genes
What cancer are aromatic hydrocarbons carcinogens of
Lung cancers
What cancer is asbestos a carcinogen of
Mesothelioma
What cancer is Aflatoxin B1 a carcinogen of
hepatocellular
What cancer are nitrosamines and amides carcinogens of
Gastric
How can ionising radiation lead to cancer
May damage cellular genes, resulting in mutations
What sources of ionising radiation do people come into contact with
- Natural radiation from earth and space
- Radiation from the nuclear power and weapons industries
- Radiation from medical tests
What are some predisposing factors to Basal cell carcinomas (BCC) and Squamous cells carcinoma (SCC)
- UV radtiaion
- Skin type 1 or 2 (freckles)
- Arsenic
- Ionising radiation
- Burn/vaccination scars
- Immunosuppression
What kind of mutation causes the formation of the Philadelphia chromosome
Balanced Translocations
Name a gene in which a point mutation can lead to cancer
H-RAS
What are the most common symptoms of Retinoblastoma
- Leucocoria
- Strabismus/squint
- Ocular inflammation
What DNA viruses can lead to cancers
- HPV - Human Papilloma Virus
- Epstein Barr Virus (EBV)
- Hepatitis B
What RNA viruses can lead to certain cancers
- Human T cell leukaemia virus type 1
- Hepatitis C virus
- (Hepatitis D)
What are the symptoms of Lung cancer
- Cough
- Haemoptysis
- Dyspnoea
- Chest pain
- Pneumonias - recurrent or slowly resolving
- Loss of appetite and weight loss
What are the signs of lung cancer
- Cachexia
- Clubbing
- Anaemia
- HPOA
- Lymphadenopathy
- Mestases
- Complications
What causes Horner’s syndrome
Preganglionic - white ramus of T1 - sympathetic trunk - superior cervical ganglion - postganglionic fibres - ophthalmic - nano ciliary - long ciliary branches
- Damage to vascular lesions of the cortex/brainstem, cervical rib, Ca lung, thyroid, oesophagus ?
What are the features of Horner’s syndrome
- Enophthalmos
- Meiosis - unopposed parasympathetic activity causing pupillary constriction
- Ipsilateral facial anhydrosis - damage to superior cervical ganglion
- Partial ptosis - paralysis of LPS
What are the features of left side colon cancer
- Bleeding/mucus pr
- Altered bowel habit
- Obstruction
- Tenesmus
- Mass on pr
What are the features of right side colon cancer
- Reduced weight
- Anaemia
- Abdominal pain
- Obstruction
What are the features of colon cancer on both sides
- Abdominal mass
- Perforation
- Haemorrhage
- Fistula
What are the symptoms of hodgkin’s lymphoma
- Enlarged painless, non-tender, rubbery superficial lymphadenopathy
- 65% cervical lymphadenopathy
- 25% constitutional upset: fever, weight loss, night sweats, pruritus
- Pel-ebstein fever
- alcohol induced lymph node pain
What are the diagnostic features of malignant melanoma
The following changes in a naevus or pigmented lesion may suggest diagnosis:
- Size - recent increase
- Shape - irregular outline
- Colour - variation
- Erythema - at edge
- Crusting, oozing or bleeding
- Itch: common
Who is most likely to present with oral squamous cell carcinomas
Older males
What are some of the risk factors for oral squamous cell carcinomas
- Old age
- Male
- Tobacco
- Alcohol
- Betel use
- Sun exposure
- Lichen planus
- Ionising radiation
- Immunosuppression and graft-versus-host disease
- Low socioeconomic status
- infection with HPV, Candida or syphilis
What are the oral effects of BQ chewing
- Occlusal tooth surface wear
- Betel chewer’s mucosa (BCM)
- Lichenoid reaction: resolves in complete cessation of habit
- Oral precancerous lesions and malignancy: Erythroluekoplakia, Oral sub mucous fibrosis (OSMF), OSCC
Describe Betel chewer’s mucosa
- Brownish red discolouration of mucosa
- Tenacious quid particles
- Tendency to desquamation and peeling
- Histology - epithelial hyperplasia and amorphous deposits calcium granules and HPV 11, 16, 18
What epithelial malignant oral neoplasms can be found
- Melanoma
- Maxillary antra carcinoma
- Glandular carcinoma
- Intra-bony carcinoma
What sarcomas can be found in the oral cavity
- Osteosarcoma
- Rhabdomyosarcoma
- Kaposi sarcoma
What are the clinical features of OSCC
- Granular ulcer with fissuring or raised exophytic margins
- Red lesion (erythroplakia)
- White lesion (leukoplakia)
- Mixed white and red lesion - speckled
- Indurated ulcer - lesion fixed to underlying tissue or to overlying skin or mucosa
- Lump
- Non-healing extraction socket
- Lymph node enlargement
- Pain or numbness
- Loose tooth
- Dysphagia
- Weight loss
What are the common OSCC sites
- Lips, lateral border of tongue and floor of the mouth
What investigations are there to diagnose OSCC
- Lesions that are non-healing persisting > 3 weeks
- Potentially malignant
- Lesions biopsy
- Fine needle aspiration or regional lymph nodes
Imaging: - Jaw/Chest radiographs
- Magentic resonance/computed tomography of head and neck
- Bronchoscopy - to exclude chest lesions
- Endoscopy
What dental management is done for patients who are currently receiving radiotherapy to the head and neck
- Normal saline mouth washes
- Benzydamine
- Nystatin
- Salivary substitute
- Jaw-opening exercises
What oral complications can arise from radiotherapy
- Nausea
- Vomiting
- Mucositis
- Taste changes
- Dry mouth
- Infections
- Caries
- pulp pain and necrosis
- Tooth hypersensitivity
- Trismus
- Osteoradionecrosis
- Craniofacial defects
Name some cancer screening methods
- Chest radiographs
- Position emission tomography
- Genetic analysis
- Cytology
- Biopsy
- Tumour markers (risk of false negs/pos.)
