Management of Oral Cancer

Question 1

Investigations for suspected SCC

Answer 1

1. Incisional biopsy
   - Necessary to grade tumour
   - Mapped biopsy: multiple specimens taken around edge to see how far cancer spread
   - fine needle aspiration of neck nodes
2. Examination under anaesthesia
3. Imaging
   - US, CT, MRI, PET (distant metastasis), RADs
   - Imaging includes neck and chest to identify or exclude lymph node and blood-borne metastases

Question 2

what needs to be assessed preoperatively? And how is this done?

Answer 2

• Important to identify type, spread and stage of carcinoma
• Comorbidity (another disease) is major determinant of treatment type and intensity
• Assess:
  1. Smokers/alcoholics for cardiovascular, respiratory, neurological or liver disease that will pose anaesthetic risk or compromise recover from surgery
  2. Nutritional status
  3. Pt’s psychological fitness for possible disfiguring surgery and future difficulty in speaking/swallowing
  4. Dental status: treat actual and potential dental infection, extraction sockets must be healed as infection or extractions may lead to osteoradionecrosis

Question 3

What do you use to assess extent and prognosis?

Answer 3

• TNM (tumour node metastasis) classification determines tx

- Most pts with oral carcinoma present at stage III or IV

Question 4

Tumour size classification

Answer 4

T1 - <2mm, <5mm depth
T2a - <2mm, 5-10mm depth
T2b - 2-4mm, <10mm depth
T3 - >4mm, >10mm depth
T4a - cortical bone, sinus, skin
T4b - masticator space, skull base, pterygoid plates, encase internal carotid artery

Question 5

Lymph node metastasis classification

Answer 5

N0 - no lymph node
N1 - single ipsilateral <3cm
N2a - single ipsilateral 3-6cm
        - N1 + extranodal
N2b - multiple ipsilateral <6cm
N2c - bilateral or contralateral <6cm
N3a - >6cm
N3b - >3mm +extranodal 
        - multiple ipsilateral or contralateral or bilateral + extranodal

Question 6

Distant metastasis classification

Answer 6

M0 - no distant metastasis

M1 - distant metastasis

Question 7

Stage 1 TNM classification

Answer 7

T1
N0
M0

Question 8

Stage 2 TNM classification

Answer 8

T2 N0 M0

Question 9

Stage 3 TNM classification

Answer 9

T3 N0 M0

T1-3 N1 M0

Question 10

Stage 4a TNM classification

Answer 10

T4a N0/1 M0

T1-4a N2 M0

Question 11

Stage 4b TNM classification

Answer 11

Any T N3 M0

T4b any N M0

Question 12

Stage 4c TNM classification

Answer 12

Any T Any N M1

Question 13

What treatments are pts recommended to have

Answer 13

• Most aggressive tx that they can tolerate and accept
• Individualised tx
• Curative or palliative care
• Usually only one chance to cure; recurrence is often the start of a prolonged course that ends in death

Question 14

What are the aims of surgery

Answer 14

• Usually performed first
• Aims to excise the carcinoma with as wide a margin as possible ideally 1cm or more (may make reconstruction difficult)
• Difficult if unpredictable irregular outlines or extends close to important anatomical structure
• Reconstructive surgery usually performed at the same time to provide better cosmetic and functional result using donor tissues

Question 15

Potential adverse effects of surgery

Answer 15

1. Immediate: wound breakdown, reconstructive flap failure
2. late: disfigurement, wound breakdown, pain, dysphasia, mastication difficulties, poor nutrition, weight loss, speech difficulties, trismus

Question 16

How is radiotherapy delivered

Answer 16

• Intensity-modulated radiotherapy allowing precisely controlled doses conforming to 3D shape of tumour determined from imaging
• Allows higher doses to be delivered to carcinoma while reducing dose and adverse effects to surrounding normal tissue (eye, bone, saliva glands)

Question 17

Potential adverse effects of radiotherapy

Answer 17

During:
- severe xerostomia, Mucositis and ulceration, acute candidosis, skin erythema
After:
- xerostomia, mucosal and skin atrophy, risk of osteomyelitis (osteoradionecrosis), scarring and fibrous tissue, cataract if eye irradiated, radiation induced malignancy

Question 18

What use does chemotherapy have on oral carcinomas

Answer 18

• Less widely used
• Usual agent is cisplatin
• Alone it gives good initial control but relapse will always occur without surgery or radiotherapy
• Best effect if it is carried out with radiotherapy

Question 19

How does targeted therapy cetuximab work?

Answer 19

• Blocks activation of EGFR which controls the cell cycle and apoptosis and has indirect effects in invasion and metastasis
• Used for advanced disease with radiotherapy and gives 10% improvement in survival

Question 20

Why does neck dissection done?

Answer 20

• An apparently uninvolved neck can harbour occult metastases. Different sites and stages have differing risks of cervical metastasis
• When surgery is to be recommended and lymph node metastases have been detected
• Other considerations: occult disease, what levels are at risk (I-IV), modality of treatment for primary, reliability of follow up, morbidity of neck treatment

Question 21

What is neck dissection?

Answer 21

• Removes all cervial lymph nodes along the jugular chain from base of skull to clavicle, together with those in the submandibular and submental triangle and posterior triangle of the neck
• May also be required to allow reconstructive surgery
• Causes permanent morbidity

Question 22

What is sentinel node biopsy

Answer 22

• Done to try to avoid neck dissection
• Radioisotope is injected around the tumour the night before surgery, followed by a blue dye at the time of surgery
• These drain via lymphatics to the sentinel lymph nodes those that are first in the drainage pathway are most likely to be involved by metastasis
• Nodes are identified at surgery by blue colour are removed and examined histologically
• If no metastasis present, rest of neck not involved and neck dissection can be avoided

Question 23

What is the failure and recurrence rate of oral carcinomas

Answer 23

• ~40% of pts suffer tx failure and recurrence, either at primary site, in lymph nodes or in distant sites (lungs, bone, liver) usually 2 years after tx
• Primary site: poor prognosis as surgery or radiotherapy already performed
• Recurrent carcinoma is often less well differentiated and more aggressive
• Can survive recurrent disease but often succumb to distant blood-borne metastases later (no effective treatment)

Question 24

When is palliative care given and what does it comprise of?

Answer 24

• Given to pts with advanced tumours or treatment failures
• Poor QOL: depression, disfigurement, long term medical side effects
• Pain control, psychological support, social and holistic needs
• Radiotherapy for active palliative tx
• Occasionally surgery

Question 25

When is the highest mortality from oral cancer

Answer 25

- Within first 2 years after diagnosis - Disease continues to claim lives but at a slower rate and those that survive - Those that survive 10 years are likely to have been cured

Question 26

Factors affecting survival from oral cancer

Answer 26

- Delay in tx of ~3 months in primary care before diagnosis - pt can progress from stage 1-3 - stage 1 - better outcome - smaller - better outcome - more posterior location - poorer outcome - smoking - lack of histological differentiation - LN spread - Blood-borne metastasis

Question 27

What are the causes of death in oral carcinomas

Answer 27

- Combination of pain, infection and difficulty in eating causes loss of weight, anaemia and deterioration of general health. This state (malignant cachexia) is ultimately fatal - Other pts, aspiration of septic material from the mouth causes bronchopneumonia - Terminal stages, oral carcinoma recurrent at the primary site can form large fumigating mass that erodes major vessels or the cranial cavity. Extranodal spread from affected lymph nodes may ulcerate through the skin and erode the jugular or carotid vessels

Question 28

What is the role of the dentist

Answer 28

1. Prevention - smoking, alcohol, education on oral carcinoma, check-ups for elderly and high risk 2. Early diagnosis - be suspicious (risk assessment on any chronic ulcer, red or white lesion, or swelling of mucous membrane) and refer for biopsy - Oral cancer screening - Monitor low-risk premalignant lesions 3. After tx - Manage simple denture problems - Alleviate post-irradiation dry mouth - Monitor for recurrence - Monitor for cervical metastasis

Question 29

When do you do a 2-week referral

Answer 29

- This 2-week wait system is for suspected cancer NOT for pts you are certain have cancer (needs immediate referral) S/S warranting 2-week: - Ulceration of oral mucosa >3weeks - Oral swellings >3weeks - all red or red and white patches on oral mucosa - Unexplained tooth mobility with no perio - Unilateral nalsal obstruction - Dysphagia >3weeks - Neck mass >3weeks - Cranial neuropathies

Question 30

how many pts develop Second primary tumours and where? Who is most at risk

Answer 30

- 5% of pts develop a second primary tumour - Usually upper aerodigestive tract or lung - Young pts, smokers and those treated by radiotherapy alone are at most risk - Tx of second primary tumour may be made more complex by previous surgery or radiotherapy

Question 31

What is verrucous carcinoma

Answer 31

- Variant of squamous cell carcinoma is a low-grade carcinoma - Warty white appearance, forming a well-circumscribed mass raised above mucosa - If small may be mistaken for papilloma - Slow-growing and spreads laterally so can be excised easily - If left untreated may progress into invasive squamous cell carcinoma