15 - Dysplasia and oral cancer 2

Question 1

Define a potentially malignant lesion.

Answer 1

• a lesion that is becoming cancer
• more likely to become cancer
• only potentially malignant

Question 2

What lesions are commonly referred to as potentially malignant lesions?

Answer 2

• leukoplakia
• erythroplakia
• lichen planus
• candidal leukoplakia
• chronic hyperplastic candidiasis
• oral submucous fibrosis

Question 3

What is the estimated malignant change for leukoplakia?

Answer 3

2.5% in 10 years

Question 4

Where do most oral carcinomas arise in the UK population?

Answer 4

Clinically normal mucosa

Question 5

What is the estimated malignant change for erythroplakia?

Answer 5

50% maybe already be carcinoma

Question 6

What are the categories of dysplasia?

Answer 6

• low grade
• high grade
• carcinoma-in-situ

Question 7

What are the categories of dysplasia based on?

Answer 7

• cellular atypia
• epithelial architectural organisation

Question 8

What are the prognostic factors in histology?

Answer 8

• pattern of invasion
• depth of invasion
• perineural invasion
• invasion of vessels

Question 9

How does the pattern of invasion impact diagnosis?

Answer 9

Bulbous rete pegs infiltrating at same level have a better prognosis than widely infiltrating small islands and single cells

Question 10

How does the depth of invasion impact diagnosis?

Answer 10

Risk of metastases for tumours bigger than 4mm is 4x greater than those smaller than 4mm

Question 11

How does the perineural invasion impact diagnosis?

Answer 11

• seen in 60% of OSCC
• most significant when tumour is within large nerve at a site far from the main tumour mass

Question 12

How does the invasion of vessels impact diagnosis?

Answer 12

Associated with lymph nodes metastases and poor prognosis

Question 13

What are the stages of dysplastic tissue?

Answer 13

• normal keratinocytes
• genetic instability or aneuploidy
• adaptive changes
• invasion (cancer)

Question 14

Define aneuploidy.

Answer 14

Abnormal amount of chromosomes in a haploid cell (only one set of chromosomes)

Question 15

What is field cancerisation?

Answer 15

• if one area is exposed to carcinogen then multiple primary cancers can be developing, some at different rates to others
• high risk site within 5cm of original primary (whole mouth/pharynx)

Question 16

Define a synchronous lesion.

Answer 16

Primary cancer that develops at the same time and similar rate to the original primary

Question 17

Define a metachronous lesion.

Answer 17

Primary cancer that develops after the original primary but is from the same field cancerisation

Question 18

What are the stages of oral cancer?

Answer 18

T - size
N - lymph nodes
M - metastases

Question 19

What is the cure rate for stage I oral cancer?

Answer 19

80%

Question 20

What is the cure rate for stage II oral cancer?

Answer 20

65%

Question 21

Describe lip cancer.

Answer 21

• lower lip, non-helaign ulcer or swelling
• causes include sunlight and smoking
• slow growth with local invasion, rarely metastasises
• good prognosis due to early detection

Question 22

What are the different oral cancer screening tools?

Answer 22

• HPV16 screening
• toluidene blue
• VELscope
• photodynamic diagnosis (PDD)
• clinical judgement of experienced clinician

Question 23

How does toluidene blue act as a screening tool?

Answer 23

• dyes tissues blue
• 50% false negatives as also dyes inflammatory lesions
• can be used for selection of biopsy site

Question 24

How does VELscope act as a screening tool?

Answer 24

• autofluorescence of tissue with blue light
• loss of fluorescence indicates change but not cause

Question 25

What is involved in primary prevention of oral cancer?

Answer 25

• smoking cessation advice
• alcohol reduction advice
• diet advice
• regular STE
• monitor any suspicious lesions and refer when threshold met