Oral Cancer Flashcards
What three key ways can cell numbers be altered?
- Increased or decrease rates of stem cell input
- Apoptosis
- Changes in the rate of proliferation or differentiation
What controls the cell cycle?
Chemical factors in the micro-environment of the cell ( i.e. stimulators and inhibitors)
Describe what is meant by “terminally differentiated” cells
Cells that are not capable of replicating
Give an example of terminally differentiated cells
Epithelial cells of oral cavity
What is the difference between dysplasia and neoplasia?
Dysplasia is reversible, neoplasia is irreversible
Define hypertrophy
An increase in cell size ( usually muscle)
Define hyperplasia
An increase in cell number (proliferation)
What is an example of hyperplasia in the oral cavity?
Gingival hyperplasia
Define atrophy
Reduction in cell size by loss of cell substance (decrease in size of body tissue)
Define hypoplasia
Reduced size of an organ that never fully developed to normal size (a developmental defect)
Define metaplasia
Reversible change in which one adult cell type is replaced by another adult cells type
(cells change to a form that is not normally found in specific tissue)
Which disorder of growth is irreversible?
Hypoplasia
define dysplasia
Abnormal growth of cells
What is a pre-malignant process?
Dysplasia
what are the three different grades of pre-invasive dysplasia?
- mild
- moderate
- severe
What does a severe grade of dysplasia indicate?
A higher risk of progressing to invasive malignancy
Define neoplasia
Uncontrolled abnormal growth of cells or tissues in the body
What are the two main classification of tumours?
- Behaviour
- Histogenesis
What are the two factors of behaviour classification that need to be considered when diagnosing a tumour?
- Benign
OR - Malignant
What type of tumour remains localised, is often encapsulated, has a slow growth rate and can be treated through local excision?
Benign tumours
What is a common type of benign salivary gland tumour, often presenting in the parotid salivary ducts?
Pleomorphic adenoma
What type of tumour metastasises, has a fast growth rate and may require additional therapy alongside excision for treatment?
Malignant tumour
What are pleomorphic cells?
Cells that grow in multiple shapes and sizes
What type of malignant oral cell shows clear pleomorphic nuclei histologically?
Oral squamous cell carcinoma
Give an example of progression of a benign tumour to a malignant one
Pleomorphic adenoma progresses to carcinoma ex pleomorphic adenoma
How would tumours be classified histogenetically?
According to the cell type they resemble (i.e. their differentiation)
If a tumour presents in covering epithelia, what is it referred to if it’s:
- Benign
- Malignant
- Papilloma
- Carcinoma
If a tumour presents in glandular epithelia, what is it referred to if it’s:
- Benign
- Malignant
- Adenoma
- Adenocarcinoma
If a tumour presents in smooth muscle, what is it referred to if it’s:
- Benign
- Malignant
- Leiomyoma
- Leiomyosarcoma
If a tumour presents in skeletal muscle, what is it referred to if it’s:
- Benign
- Malignant
- Rhabdomyoma
- Rhabdomyosarcoma
If a tumour presents in bone forming connective tissue, what is it referred to if it’s:
- Benign
- Malignant
- Osteoma
- Osteosarcoma
If a tumour presents in cartilage, what is it referred to if it’s:
- Benign
- Malignant
- Chondroma
- Chondromasarcoma
If a tumour presents in fibrous tissue, what is it referred to if it’s:
- Benign
- Malignant
- Fibroma
- Fibromasarcoma
If a tumour presents in blood vessels, what is it referred to if it’s:
- Benign
- Malignant
- (Haem) angioma
- Angiosarcoma
If a tumour presents in adipose tissue, what is it referred to if it’s:
- Benign
- Malignant
- Lipoma
- Liposarcoma
If a tumour presents in melanocytes, what is it referred to if it’s:
- Benign
- Malignant
- Melanocytic naevi
- Malignant melanoma
What type of tumours may be undifferentiated, showing no definite form of differentiation?
Highly malignant tumours
The prediction of the probable course and outcome of disease
Prognosis
What is prognosis important for?
Appropriate treatment and estimation of survival
Give an example of an odd tumour with unpredictable behaviour
Malignant melanoma
What aids in the diagnosis, staging and treatment of tumours?
Knowing the patterns of spread of tumour types
What does a histological assessment determine?
How well differentiated the tumour cells are
What tumours have better prognosis, well differentiated or undifferentiated tumours?
Well differentiated
What does tumour staging describe?
The anatomical extent of disease
what type of classification is used to stage cancer?
TNM classifications of malignant tumours
What does each letter component of “TNM” describe?
T- extent of primary tumour
N- absence or presence and extent of regional lymph node metastasis
M- absence or presence of distant metastasis
When staging, what does a higher number given to TNM indicate?
A more extensive disease
What does a higher tumour stage indicate in regards to prognosis?
Poorer prognosis
What causes cancer?
Mutations in genes resulting in a cell which grows and proliferates at an uncontrolled rate, and is unable to repair DNA within itself or undergo apoptosis
What are the common causes of genetic errors?
- Inherited
- Viruses
- Exposure to chemicals and radiation
Define mouth cancer
A variety of malignant tumours that develop in the mouth, affecting the lips, salivary glands, tongue, gums, palate and inside of cheeks
What type of cancer is commonly associated with mouth cancer?
Squamous cell carcinoma
What age group does oral cancer often present in?
Older age group ( approx over 55 years old)
In the UK, how often does death associated with mouth cancer occur?
1 person every 3 hours
What are the two largest risk factors of oral cancer?
- Tobacco
- Alcohol
What are less common risk factors for oral cancer?
- poor diet/obesity
- immunological defect
- sunlight ( UV)
If a patient smokes tobacco and drinks alcohol, how much more likely are they to develop oral cancer than a patient who doesn’t smoke or drink?
24 times more likely
In what area of the oral cavity is mouth cancer most common?
In the sublingual gutter ( space between tongue and FOM)
Why is oral cancer most likely to present in the sublingual gutter?
Due to pooling of carcinogens from tobacco and/or alcohol in this area
Describe the consequence of alcohols thinning effect on the oral mucosa
It makes mucosa more permeable to carcinogens, which can enter through the epithelial cell barrier
What mutagen and carcinogen is alcohol metabolised to?
Acetaldehyde
How is ethanol broken down into acetaldehyde in the oral cavity?
By bacteria in oral cavity and salivary glands
What is the daily recommendation of alcohol for both females and males?
2 units
What is the weekly recommendation of alcohol for females and males?
14 units
How many days are recommended to be taken as ‘alcohol free’ in a week?
2 days
What type of food is affective in preventing oral cancer and why?
Fruits and vegetables as they provide vitamins and supplements
Cancer in what location is most likely to present due to UV light exposure?
Lip cancer
What are the three main viruses associated with oral cancer?
- human papillomavirus (HPV)
- Epstein-barr virus (EBV)
- Human immunodeficiency virus (HIV)
Which infectious virus has the largest predisposition for milignant change in the oral cavity?
HPV
What type of HPV is associated with oral mucosa?
Beta type
What are the two high risk HPV types associated with the oral cavity?
HPV 16 and HPV 18
Which HPV type has oncogenes properties ( tumour development)?
HPV 16
What type of cell does HPV infect?
Undifferentiated proliferative basal cells
Interactions between what proteins cause HPV infection to result in latency and malignant transformation?
Interactions of viral (E6 and E7) proteins with p53 and pRB
What are the two types of benign oral HPV lesions?
- Papilloma
- Condylomata
What is similar to a papilloma but instead is a multiple lesion phenomena?
Condylomata
Define exophytic
Growth of a tumour outwards
What are the two main risk factors for HPV?
- number of sexual partners
- weakened immune system
What virus causes infectious mononucleosis ( glandular fever)?
EBV
What rare cancer is associated with EBV?
Burkitt’s lymphoma
Which virus causes an increased risk of kaposi sarcoma?
HIV
What are oral symptoms of HIV?
Candidiasis, hairy leukoplakia, accelerated perio disease, kaposi sarcoma, salivary gland disease and oral ulcers
How is HIV treated?
Highly affective antiviral treatment (HAART)
What is kaposi Sarcoma- associated herpesvirus (KSHV) also known as?
Human herpesvirus-8 (HHV-8)
What are the first symptoms of kaposi sarcoma?
Red, purple or brown patches/nodules on the skin/mucosa
Abnormal thickening of the epithelium
Hyperkeratosis
What are squamous cell papilloma’s pedunculated to?
A stalk
Atypical epithelial alterations limited to the surface squamous epithelium
Epithelial dysplasia
What characterises epithelial dysplasia?
Cytological and architectural alterations with a loss of normal maturation and differentiation. It is a premalignant process.
A benign histologic finding characterised by the proliferation of the basal cells
Basal cell hyperplasia
Abnormal keratinisation occurring prematurely within individual cells or groups of cells
Dyskeratotic cells
Define pleomorphism
Cells or their nucleus having variation in size and shape
What is the key feature of identifying oral squamous cell carcinoma histologically?
Invasion of adjacent normal tissues
A keratinised structure found in regions where abnormal squamous cells form concentric layers
Keratin pearl
If squamous carcinoma cells are better differentiated (more like normal epithelium), how would this effect tumour grade and prognosis?
Lower tumour grade and better prognosis
If squamous carcinoma cells are poorly differentiated, how would this effect tumour grade and prognosis?
Higher tumour grade and lower prognosis
The application of a test to people who are apparently free of disease to identify those who may have the disease from those who may not
Screening
Define primary prevention and give an example
Prevents a disease from developing ( e.g. risk factor education to patients)
Define secondary prevention and give an example
To detect disease while it is localised or ‘early’ (e.g. screening oral cavity)
Define tertiary prevention and give an example
To mitigate the morbidity from established disease and to improve quality of life (e.g. programs and support groups for people living with disease)
What are the three types of population screening programmes?
- Mass screening
- Selective screening
- Opportunistic screening
What type of screening are dentists involved in?
Opportunistic screening, as patients present voluntarily to dentists to be assessed.
For any screening programme to be successful, what are the two qualities it must possess?
High sensitivity and specificity
What is meant by the term ‘sensitivity’ in regards to screening?
The proportion of the population who are correctly classified as having a disease
What is meant by the term ‘specificity’ in regards to screening?
The proportion of the population correctly classifies as disease-free
What order of sensitivity and specificity do screening tests aim to have in order for them to be usefully applied to the population?
80% or more
What did the one properly conducted study (randomised controlled trial carried out over 15 year period) on mouth cancer screening evaluate?
Clinical or cost efficacy of mouth cancer screening
What does OPMD stand for?
Oral potentially malignant disorders
What is an important example of OPMD?
Lichen planus
How can lichen planus manifest?
- white patches
- reticular patches
- rows of patches
- ulcerated patches
- plaques
What does OPML stand for?
Oral potentially malignant lesions
When would size of a lesion be concerning in terms of potential for malignancy?
If a lesion is above 20cm in size
When would texture of a lesion be concerning in terms of potential for malignancy?
If the lesion is irregular in texture, more non-homogenous
When would colour of a lesion be concerning in terms of potential for malignancy?
Red lesions are more worrying, followed by speckled, then white lesions
What sites in the mouth are highest risk for malignancy?
Tongue and FOM
Which sex are at greater risk of developing malignancy?
Females
At what age is it most common to develop malignancy?
> 50 years
A white patch of unknown cause is known as?
Leukoplakia
A red patch of unknown cause is known as?
Erythroplakia
What is meant by indurated margins?
Heaped, thick and rubbery texture to touch
AND
is a sign of cancer invading underlying mucosal margin
Define endophytic lesion
Inwards growing lesion
Define exophytic lesion
Outwards growing lesion
In what scenario would cancers become painful?
When they are secondary infected or when they invade nerves (perineural spread)
How is tumour/lesion size classified?
By T classifications ( T1, T2, T3, T4)
What size would a T1 lesion be?
<2cm
What size would a T2 lesion be?
2-4cm
What size would a T3 lesion be?
4-6cm
What size would a T4 lesion be?
> 6cm or any lesion that involves the underlying bone
When should you refer a patient presenting with an unusual ulcer?
If the ulcer does not heal within 2-3 weeks
Who should you refer a patient with an unusual lesion to?
Nearest Maxillofacial department on urgent 2 week referral;
What sort of imaging will the Maxillofacial department take to assess patient for potential malignancy?
Head/neck MRI scan and CT of chest
What is ‘geographic’ tongue also known as?
Benign migratory glossitis
What is the key characteristic of geographic tongue?
Appearance of red or white patches that comes and goes- hence ‘migratory’
What is geographic tongue a result of?
Deviation in natural turnover in cells, where some cells turnover fast and are evolved and other turn over slowly, heaping up and forming the patches we see
Why does ‘black hairy tongue’ occur?
Where mastication cannot clean dorsum of tongue, elongation of the papilla occurs which becomes infected by pigmented bacteria causing the black appearance
How can ‘black hairy tongue’ be treated?
Simply with OH, by focusing cleaning to the tongue
Define ‘papillary hyperplasia’
Benign lesion of the oral mucosa which is characterised by enlarged papillae
What may a slight white appearance along the occlusal plane of lateral tongue indicate about a patient?
That they may grind their teeth or clench
What is a blister in the oral cavity also known as?
Bullae
What benign features can normally be seen when assessing the buccal mucosa?
- linea alba
- chewing of cheek
- small white spots
What is linea alba?
Linear white line at the level of occlusal plane (indicates clenching habit)
Why can benign small white spots appear in buccal mucosa?
Caused by ectopic sebaceous glands
Give 9 common examples of benign oral lesions
- Aphthous ulceration
2.lipoma - Mucoceole
- Epulis
- Leaf fibroma
- Denture induced hyperplasia
- Papillary hyperplasia
- Papilloma
- Tori palatinus or mandibularis
What is a mucocoele?
A benign mucous containing cystic lesion of the minor salivary gland.
What often causes mucocoele’s to form?
Trauma to the area
What is an epulis?
A benign mass-like growth in the mouth that typically grows over or around a tooth
What is a pyogenic granuloma?
A harmless overgrowth of tiny blood vessels on the skin
What is leaf fibroma and why does it occur?
A fibrous epulis forms underneath the palatal base of a denture.
What are examples of benign lesions caused by ill-fitting dentures?
- leaf fibroma
- denture induce hyperplasia
- papillary hyperplasia
What is torus palatinus?
A harmless, painless bony growth located on the roof of the mouth
Why can torus become easily traumatised by mastication to dentures?
As they have thin mucosal layer
What is torus mandibularis and where does it occur most often?
A benign bony outgrowth normally located on lingual aspect of alveolus bilaterally
When doing an extra-oral exam as part of cancer screening, what are you looking for?
Lymphadenopathy (enlargement of the lymph nodes)
How cancerous lymph nodes present ?
Firm, rubbery and non-tender
What are features of oral malignancy?
- red/white/speckled lesion
- ulcerated areas
- high risk sites
- asymptomatic
- unknown duration
- risk factor history
What is a ‘mapping biopsy’?
Incisional biopsies are carried out at multiple sites
What structures does ‘ head and neck cancer’ encompass?
Cancers of the:
- mouth
- oropharynx
- nasopharynx
- hypopharynx
- nose
- paransal sinuses
- larynx
- salivary glands
- ear
What type of mucosa do squamous cell carcinomas typically arise from?
Lining mucosa
What is an example of cancer of the salivary glands?
Polymorphous adenocarcinoma
What is an example of cancer of Odontogenic epithelium?
Ameloblastic carcinoma
What is an example of malignant skeletal muscle tumour?
Rhabdomyosarcoma
What does aneuploidy mean? And where is it common?
Altered DNA content, common in tumour cells
What very simplified stages are involved in the ‘multi step theory of carcinogenesis?
- Initiation
- Promotion
What happens in the initiation stage of the ‘multi step theory of carcinogenesis?
DNA damage and mutation
What happens in the promotion stage of the ‘multi step theory of carcinogenesis?
Clonal expansion of abnormal cells leading to cancer
What are the four key elements of tumour growth?
- replication
- escape from senescence (deterioration with age)
- evasion of apoptosis
- limitless replicative potential
What are the four key elements in cancer development?
- Tumour growth
- Invasive growth
- Angiogenesis
- Metastasis
What are the three key factors involved in invasive growth of a tumour?
- Reduction in cell-cell adhesion
- Invasion of basement membrane and stroma
- Tumour cell motility
What is ‘the angiogenic switch’?
Development of rich blood supply around a tumour
What is a critical step in progression of a small localised tumour to a bigger one with metastatic potential?
Angiogenesis
What is another term used to describe metastasis?
Secondaries
What are tumour implants that are discontinuous with the primary lesion?
Metastasis
What organs are very effective at arresting circulating cancer cells?
Lung and liver
What is epithelial dysplasia?
A premalignant process- atypical epithelial alterations limited to the surface squamous epithelium
Dysplasia involves the invasion of adjacent normal tissues. True or false?
False, limited to the surface squamous epithelium
How does WHO grade epithelial dysplasia?
Mild
Moderate
Severe
What is the binary system for grading epithelial dysplasia?
Low grade
High grade
What grade of epithelial dysplasia is described:
Disorganisation, increase proliferation and atypia of basal cells
Mild dysplasia
What grade of epithelial dysplasia is described:
Very abnormal, affects full thickness of epithelium
Severe dysplasia
What grade of epithelial dysplasia is described:
More layers of disorganised basaloid cells, atypia, suprabasal mitosis
Moderate dysplasia
Define oral potentially malignant disorders
Oral mucosal lesions that have a potential risk of developing into oral SCC
Give three examples of oral potentially malignant disorders
- Oral sub-mucous fibrosis
2.lichen planus
3.chronic hyperplastic candidosis
How long is follow up treatment after surgical excision of SCC?
5 years
what is the gold stands tool for excisions of potentially malignant lesions?
Carbon dioxide laser
What are lichenoid reactions often triggered by?
A long-standing chromic irritation to amalgam or metal-based restorations
what is an indolent tumour?
A tumour that causes little or no pain
What do groups of cells that display invasive growth have high levels of?
Autocrine pro-migratory factors and proteolytic enzymes
