Oral Cancer

Question 1

Incidence of Oral Cancer in UK (Male & Female)

Answer 1

3% of all cancers
M = 20/100,000
F = 9.3/100,000

Question 2

5 year survival rate of Oral Cancer in UK

Answer 2

58%

Question 3

Percentage of pt’s that present with late stage Oral cancer

Answer 3

70%

Question 4

Risk factors for oral cancer

Answer 4

Tobacco
Alcohol
Sunlight
Infections; Viruses (HPV -associated with 60% of OPSCC), Fungi (Candida), bacteria.

Question 5

Recommended alcohol limits for men & women

Answer 5

14 units of alcohol a week

1 unit = 1 shot, 3 units = 1 pint of beer or 1 large glass of wine (175ml)

Question 6

Definition of a Potentially Malignant Oral Lesion (PMOL)

Answer 6

A morphologically altered tissue in which cancer is more likely to occur than in its apparently normal counterpart

Question 7

WHO definition of a Leukoplakia

Answer 7

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.

Question 8

Prevalence of Leukoplakias in UK

Answer 8

2.8%

Question 9

Types of Leuoplakia & 5 Yr Risk of Malignant Change

Answer 9

Homogeneous = 1-5% 
Non-homogeneous = 20%

Question 10

WHO definition of Erythroplakia

Answer 10

Red patch on the oral mucosa which cannot be characterised clinically or histologically as due to any other condition.

Question 11

How large can the region of field change be?

Answer 11

7cm away from the visible lesion (‘field’ of abnormal mucosa)

Question 12

What are the architectural features of atypia in the epithelium?

Answer 12

Irregular epithelial stratification
Loss of basal cell polarity
Drop-shaped rete processes

Question 13

What are the cytological features of atypia in the epithelium?

Answer 13

Increased number of mitotic figures
Cellular & nuclear pleomorphism
Nuclear hyperchromatism ('ploidy')
Individual cell keratinisation
Loss of intercellular adherence

Question 14

What are the types of dysplasia?

Answer 14

1. Mild = architectural changes in lower third, mild cytological atypia.
2. Moderate = architectural changes in mid third, moderate cytological atypia.
3. Severe = architectural changes into upper third, severe atypia and numerous mitosis.
4. Carcinoma-in-situ = severe dysplasia/abnormal archiecture involving the full epithelium thickness, pronounced cytological atypia (mitotic abnormalities frequent), malignant but NOT invasive.

Question 15

Percentage of Homogeneous Leukoplakias that show Dysplasia

Answer 15

20%

Question 16

Percentage of Non-Homogeneous Leukoplakias that show Dysplasia

Answer 16

50%

Question 17

Fate of dysplastic lesions

Answer 17

Malignant = 20%
Regress = 20%
No change = 40%
Increase in size = 20%

Question 18

High risk sites for dysplasia & Oral cancer (80%)

Answer 18

Lateral margins of the tongue
Floor of mouth
Retromolar, soft palate & fauces.

Question 19

Name Four Potentially Malignant Conditions

Answer 19

1. Chronic Hyperplastic Candidosis
2. Actinic keratosis
3. Oral Submucous Fibrosis (OSMF) -risk of malignant transformation = 2.3-7.6%
4. Lichen Planus -risk of malignant change <1% (higher in erosive or atrophic forms).

Question 20

Symptoms of Oral Cancer

Answer 20

None
Soreness/irritation
Paraesthesia/Anaesthesia
Disruption of function
Dysphagia

Question 21

Signs of Oral Cancer

Answer 21

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

Question 22

Important Pathological Features of Oral Cancer

Answer 22

1. Type of Oral cancer.
2. Grade (well, moderately and poorly differentiated)
3. Stage (TNM)

Question 23

What do the different grades mean?

Answer 23

Low grade = well differentiated cells.
Moderately differentiated (most pts have this) 
Poorly differentiated =very aggressive, doesn't resemble tissue of origin at all!

Question 24

What does TNM stand for?

Answer 24

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!)

Question 25

What is Extracapsular Spread and how does it influence survival?

Answer 25

Tumour extends out of the node into soft tissues | Decreases survival by 50%

Question 26

What factors affect prognosis?

Answer 26

``` 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). ```

Question 27

Management of Oral Cancer

Answer 27

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.

Question 28

Management in Primary Dental Care

Answer 28

Do NOT biopsy | Prompt referral to local oral & maxillofacial surgery department -2 week target!

Question 29

What is the role of the Radiologist in HNCs?

Answer 29

1. Diagnosis -does the pt have imaging signs of cancer? 2. Staging -how far has the cancer spread? 3. Surveillance -has the cancer recurred after treatment?

Question 30

What is the purpose of Staging?

Answer 30

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.

Question 31

What is the (almost) universal standard for cancer staging?

Answer 31

TNM (Tumour, Node, Metastases)

Question 32

What is the mainstay of radiological staging for oral cancer?

Answer 32

Magnetic Resonance Imaging (MRI) -uses magnets & radio waves to produce pictures of the body based on the density of protons.

Question 33

When is an MRI contraindicated & what imaging can be used instead?

Answer 33

``` 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. ```

Question 34

What does T0, T1, T2, T3 and T4 mean?

Answer 34

``` 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. ```

Question 35

What does N0, N1, N2 and N3 mean?

Answer 35

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.

Question 36

What does M0 and M1 mean?

Answer 36

Note: M = distant metastasises BEYONG the local lymph nodal drainage. M0 = no distant metastases. M1 = distant metastases present, e.g. lung.

Question 37

When can Positron Emission Tomography be used and what does it measure?

Answer 37

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).