Oral Squamous Cell Carcinoma (OSCC)

Question 1

What is the epidemiology of oral cancer?

Answer 1

• Worldwide annual new cases - 378,000
(Parkin, 1988)
• Sixth most common cancer in the world
• Death rate per million in UK similar to cervical
cancer
• Death rate in UK higher than skin cancer

It’s more commonly found on the floor of the mouth in the West and on the buccal mucosa in India.

Question 2

What is the % survival rate depending on the stage of the oral cancer?

Answer 2

Question 3

What is the % survival for the different types of oral cancer?

Answer 3

Question 4

What is the suggested clinical algorithm for chronic ulcers?

Answer 4

Question 5

What are the “red flag” symptoms and signs of head and neck cancer if they last for more than three weeks?

Answer 5

Symptoms
• Sore throat
• Hoarseness
• Stridor
• Difficulty in swallowing
• Lump in neck
• Unilateral ear pain
Signs
• Red or white patch in the mouth
• Oral ulceration, swelling, or loose tooth
• Lateral neck mass
• Rapidly growing thyroid mass
• Cranial nerve palsy
• Orbital mass
• Unilateral ear effusion

Question 6

What are the National Institute for Health and
Clinical Excellence (NICE) guidlines on
referral for suspected cancer?

Answer 6

Recommends urgent referral for a person with:
– Unexplained red and white patches
(including suspected lichen planus) of
the oral mucosa that are painful, or
swollen, or bleeding.
– Unexplained ulceration of the oral
mucosa, or mass persisting for more
than 3 weeks.

NICE also recommends that any person with persistent symptoms or signs related to the oral cavity in whom a definitive diagnosis of a benign lesion cannot be made should be referred or followed up until the symptoms and signs disappear.

Question 7

What are some presentations where cancer might easily be missed?

Answer 7

• Persistently enlarged neck nodes in younger patients (30-50 years)
Tumours are often small or occult within normal looking tonsils.

Question 8

What do these images show?

Answer 8

A = Squamous cell cancer of upper maxillary alveolus with an area of denture hyperplasia.

B = Squamous cell cancer of lateral border of tongue.

Question 9

What is the aetiology of oral cancer?

Answer 9

• Tobacco
• Alcohol
• Local factors
• Ethnic factors
• Genetic factors
• Diet and vitamins
• Premalignancy

Question 10

What are the risk factors of oral cancer?

Answer 10

• Tobacco- x20 fold increase under 46 years
• Alcohol- x5 fold increase
• Synergistic = x50

Question 11

How does oral cancer look on a biopsy?

Answer 11

• Breakdown of basement membrane
• Invasion

Question 12

What’s this the histology of?

Answer 12

Squamous cell carcinoma

Question 13

What does this histology show?

Answer 13

Perineural and vascular invasion

Question 14

How does oral cancer spread?

Answer 14

Question 15

What are the prognostic indicators of oral cancer?

Answer 15

• Age
• Sex
• Stage:
- Site
- Tumour size
- Nodal status
- Metastases (distant)
- Pathology

Question 16

What do the prognostic indiactors tell you?

Answer 16

_Site: _Prognosis decreases towards the back of the
mouth.

Tumour size: The larger the tumour, the worse the
prognosis

_Nodal status: _

• Presence of positive nodes decreases
likelihood of survival by 50%
• Up to 40% of neck dissections show occult
metastases
• Extracapsular lymph node spread is of
major significance
• Stepwise spread in lymph node chain

Metastases:

• 50% show evidence of distant spread at
autopsy
• Lung, bones, liver, brain
• In the past , relatively rare cause of death (4%)
• Successful local control is leading to an
increased death rate from distant spread

Pathology:
• Degree of differentiation
- well, moderate or poor
• Pattern of invasive edge
- blunt
- irregular cords or strands
• Adequacy of excision

Question 17

What’s been an epidemiological observation?

Answer 17

For men over 80 incidence of oral cancer has halved since 1975 70’s stable, 40-50’s rates have doubled.

The incidence of head and neck cancer has
been gradually increasing over the last 3
decades (50% since 1989) but the exposure to classical risk factors is
decreasing, possibly due to HPV.

Question 18

What’s the research results about the link between HPV and oropharyngeal SCC?

Answer 18

• High risk HPV DNA (subtypes 16/18) found in up to 40-66% of Oropharyngeal (tongue base/ tonsil) SCC
• Clinically and molecularly distinct from HPV negative tumours
• Found in younger males (30-40 years) with no classical risk factors (should a HPV for boys be introduced?)
• Sexually transmitted

BUT HPV+ tumours have a more favourable prognosis:

– Longer, stage specific survival
– Predicted responsiveness to induction chemotherapy and
chemoradiation in stage III/IV tumours
– Predicted better response to radiotherapy alone

Question 19

How does E6 (from the HPV) interact with P53 and infect cells?

Answer 19

Question 20

What are the pathology findings about surrogate markers from biopsies?

Answer 20

• HPV viral proteins (E7) also interact with another cell
cycle protein pRb
• Inactivation of pRb by HPV results in increased
expression of another protein called p16 (negative
feedback).
• P16 over-expression can be detected by
immunohistochemistry in tissue sections and can
function as a surrogate marker for HPV infection.

Question 21

What are some non OSCC malignancies of the oral cavity?

Answer 21

• Minor salivary Gland Tumours
• Oral Lymphomas
• Oral Malignant Melanoma (shown in picture)
• Oral Sarcomas