Oral Cancer Flashcards
Incidence of Oral Cancer in UK (Male & Female)
3% of all cancers
M = 20/100,000
F = 9.3/100,000
5 year survival rate of Oral Cancer in UK
58%
Percentage of pt’s that present with late stage Oral cancer
70%
Risk factors for oral cancer
Tobacco
Alcohol
Sunlight
Infections; Viruses (HPV -associated with 60% of OPSCC), Fungi (Candida), bacteria.
Recommended alcohol limits for men & women
14 units of alcohol a week
1 unit = 1 shot, 3 units = 1 pint of beer or 1 large glass of wine (175ml)
Definition of a Potentially Malignant Oral Lesion (PMOL)
A morphologically altered tissue in which cancer is more likely to occur than in its apparently normal counterpart
WHO definition of a Leukoplakia
A white patch that cannot be rubbed off and cannot be characterised clinically or histologically as any other disease and that is not associated with any physical or chemical causative agent EXCEPT the use of tobacco.
Prevalence of Leukoplakias in UK
2.8%
Types of Leuoplakia & 5 Yr Risk of Malignant Change
Homogeneous = 1-5% Non-homogeneous = 20%
WHO definition of Erythroplakia
Red patch on the oral mucosa which cannot be characterised clinically or histologically as due to any other condition.
How large can the region of field change be?
7cm away from the visible lesion (‘field’ of abnormal mucosa)
What are the architectural features of atypia in the epithelium?
Irregular epithelial stratification
Loss of basal cell polarity
Drop-shaped rete processes
What are the cytological features of atypia in the epithelium?
Increased number of mitotic figures
Cellular & nuclear pleomorphism
Nuclear hyperchromatism ('ploidy')
Individual cell keratinisation
Loss of intercellular adherenceWhat are the types of dysplasia?
- Mild = architectural changes in lower third, mild cytological atypia.
- Moderate = architectural changes in mid third, moderate cytological atypia.
- Severe = architectural changes into upper third, severe atypia and numerous mitosis.
- Carcinoma-in-situ = severe dysplasia/abnormal archiecture involving the full epithelium thickness, pronounced cytological atypia (mitotic abnormalities frequent), malignant but NOT invasive.
Percentage of Homogeneous Leukoplakias that show Dysplasia
20%
Percentage of Non-Homogeneous Leukoplakias that show Dysplasia
50%
Fate of dysplastic lesions
Malignant = 20%
Regress = 20%
No change = 40%
Increase in size = 20%
High risk sites for dysplasia & Oral cancer (80%)
Lateral margins of the tongue
Floor of mouth
Retromolar, soft palate & fauces.
Name Four Potentially Malignant Conditions
- Chronic Hyperplastic Candidosis
- Actinic keratosis
- Oral Submucous Fibrosis (OSMF) -risk of malignant transformation = 2.3-7.6%
- Lichen Planus -risk of malignant change <1% (higher in erosive or atrophic forms).
Symptoms of Oral Cancer
None Soreness/irritation Paraesthesia/Anaesthesia Disruption of function Dysphagia
Signs of Oral Cancer
Persistent ulcer Persist white, red or mixed patch Exophytic mass Fixation of tissue Induration (firmness to tissue) Sensory/motor deficit Tooth movement/mobility Lymph node enlargement/fixation
Important Pathological Features of Oral Cancer
- Type of Oral cancer.
- Grade (well, moderately and poorly differentiated)
- Stage (TNM)
What do the different grades mean?
Low grade = well differentiated cells. Moderately differentiated (most pts have this) Poorly differentiated =very aggressive, doesn't resemble tissue of origin at all!
What does TNM stand for?
Tumour (>5mm = worse prognosis)
Node (60% of pts will have metastases to regional lymph nodes).
Metastases (haematogenous spread is a late event, most commonly to the lungs (CT scan of chest!)
What is Extracapsular Spread and how does it influence survival?
Tumour extends out of the node into soft tissues
Decreases survival by 50%
What factors affect prognosis?
Site Grade Stage; size (T) & spread (NM) Extracapsular spread Multiple primaries (15-20%); synchronous (multi sites at same time) or metachronous (multi sites at diff times).
Management of Oral Cancer
Confirm/establish diagnosis by biopsy & thorough clinical exam.
Imaging for extent of spread (MRI, CT of chest, PET scan)
Review at MDT meeting.
Tx plan formulated; surgical excision &/or RT &/or CT &/or Palliation.
Management in Primary Dental Care
Do NOT biopsy
Prompt referral to local oral & maxillofacial surgery department -2 week target!
What is the role of the Radiologist in HNCs?
- Diagnosis -does the pt have imaging signs of cancer?
- Staging -how far has the cancer spread?
- Surveillance -has the cancer recurred after treatment?
What is the purpose of Staging?
To accurately define the extent of the primary cancer, including the structures that it invades into as well as those structures that might be included in the resection if surgery is performed.
Also to evaluate the spread to regional lymph nodes.
What is the (almost) universal standard for cancer staging?
TNM (Tumour, Node, Metastases)
What is the mainstay of radiological staging for oral cancer?
Magnetic Resonance Imaging (MRI) -uses magnets & radio waves to produce pictures of the body based on the density of protons.
When is an MRI contraindicated & what imaging can be used instead?
If pt has pacemaker, unable to tolerate the scanning environment (e.g. claustrophic). Computed Tomography (CT) can be used instead -produces a series of slices based on the X-ray density of the pt.
What does T0, T1, T2, T3 and T4 mean?
T0 = no evidence of primary tumour. T1 = < or = 2cm, DOI <5mm T2 = < or = 2cm, DOI >5mm but < or = to 10mm OR > or = 2cm and < or = 4 cm and DOI < or = to 10mm. T3 = > 4cm, DOI > 10mm T4 = invades deep structures.
What does N0, N1, N2 and N3 mean?
N0 = no LN metastases
N1 = single ipsilateral node < 3cm, ENE -ve.
N2; a = single ipsiltaeral node > 3cm but < 6cm, ENE -ve.
b = multiple ipsilateral nodes < 6cm, ENE -ve.
c = contralateral/bilateral node(s) < 6cm, ENE -ve
N3; a = any node > 6cm, ENE -ve
b = any node that is ENE +ve.
What does M0 and M1 mean?
Note: M = distant metastasises BEYONG the local lymph nodal drainage.
M0 = no distant metastases.
M1 = distant metastases present, e.g. lung.
When can Positron Emission Tomography be used and what does it measure?
In surveillance of cancer pts when both the clinical exam and MRI are uncertain, PET can be used to measure glucose metabolism (cancer cells more metabolically active).
