15 - Dysplasia and oral cancer 2 Flashcards
Define a potentially malignant lesion.
- a lesion that is becoming cancer
- more likely to become cancer
- only potentially malignant
What lesions are commonly referred to as potentially malignant lesions?
- leukoplakia
- erythroplakia
- lichen planus
- candidal leukoplakia
- chronic hyperplastic candidiasis
- oral submucous fibrosis
What is the estimated malignant change for leukoplakia?
2.5% in 10 years
Where do most oral carcinomas arise in the UK population?
Clinically normal mucosa
What is the estimated malignant change for erythroplakia?
50% maybe already be carcinoma
What are the categories of dysplasia?
- low grade
- high grade
- carcinoma-in-situ
What are the categories of dysplasia based on?
- cellular atypia
- epithelial architectural organisation
What are the prognostic factors in histology?
- pattern of invasion
- depth of invasion
- perineural invasion
- invasion of vessels
How does the pattern of invasion impact diagnosis?
Bulbous rete pegs infiltrating at same level have a better prognosis than widely infiltrating small islands and single cells
How does the depth of invasion impact diagnosis?
Risk of metastases for tumours bigger than 4mm is 4x greater than those smaller than 4mm
How does the perineural invasion impact diagnosis?
- seen in 60% of OSCC
- most significant when tumour is within large nerve at a site far from the main tumour mass
How does the invasion of vessels impact diagnosis?
Associated with lymph nodes metastases and poor prognosis
What are the stages of dysplastic tissue?
- normal keratinocytes
- genetic instability or aneuploidy
- adaptive changes
- invasion (cancer)
Define aneuploidy.
Abnormal amount of chromosomes in a haploid cell (only one set of chromosomes)
What is field cancerisation?
- 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)
Define a synchronous lesion.
Primary cancer that develops at the same time and similar rate to the original primary
Define a metachronous lesion.
Primary cancer that develops after the original primary but is from the same field cancerisation
What are the stages of oral cancer?
T - size
N - lymph nodes
M - metastases
What is the cure rate for stage I oral cancer?
80%
What is the cure rate for stage II oral cancer?
65%
Describe lip cancer.
- 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
What are the different oral cancer screening tools?
- HPV16 screening
- toluidene blue
- VELscope
- photodynamic diagnosis (PDD)
- clinical judgement of experienced clinician
How does toluidene blue act as a screening tool?
- dyes tissues blue
- 50% false negatives as also dyes inflammatory lesions
- can be used for selection of biopsy site
How does VELscope act as a screening tool?
- autofluorescence of tissue with blue light
- loss of fluorescence indicates change but not cause
What is involved in primary prevention of oral cancer?
- smoking cessation advice
- alcohol reduction advice
- diet advice
- regular STE
- monitor any suspicious lesions and refer when threshold met
