9.2 Benign, premalignant and malignant tumours of relavence to dentistry Flashcards
How have mouth cancer rates increased over the past decae?
Increase in cases by over 30%
Why do dentists play an important role in mouth cancer?
- We see asymptomatic patients (check-ups) and are ideally placed to detect head and neck cancers at early stages
- Dentists may be involved in the treatment of tumours in the head and neck, and treating patients with cancers at other sites
- Restorative dentists may be involved in treating the dentition of mouth cancer pts
- See patients over a period of years so can identify changes over time
What are the oral consequences of radio and chemo therapy?
- Damage to salivary glands and salivary flow, xerostomia and increased caries risk
- Risk of osteo-radionecrosis of the jaws
What is the most common oral malignancy?
Oral squamous cell carcinoma.
What is the difference between reactive vs neoplastic cell proliferations?
Reactive = response to a stimulus, lesion regresses when stimulus is removed
Neoplastic = proliferation of cells which is autonomous and persists after the initiating stimulus has been removed, can be benign or malignant.
What is the difference between hyperplasia and hypertrophy?
Hyperplasia = increase in number of cells
Hypertrophy = increase in size of cells
Name some reactive oral mucosal lesions.
- Fibro-epithelial polyps
- Fibrous epulis
- Denture-induced granuloma
- Pulp polyp
- Pyogenic granuloma
- Peripheral giant cell granuolma (giant cell epulis)
- Traumatic ulcer
Name some neoplastic benign tumours of the oral cavity.
- Squamous cell papilloma
- Fibroma
- Haemangioma
- Lymphangioma
- Neurofibroma
- Neurilemmoma
- Pleomorphic adenoma
- Lipoma
- Adenoma
- Osteoma
- Ossifying fibroma
Name some neoplastic malignant tumours of the oral cavity.
- SCC
- BCC (most common, rarely metastasise)
- Malignant melanoma
- Fibrosarcoma
- Liposarcoma
- Malignant lymphoma
- Minor salivary gland adenocarcinomas
- Osteosarcoma
- Range of malignant salivary gland tumours
Which sites are most commonly affected by SCC?
- Larynx, oral cavity and paranasal sinuses
- Frequently metastasise to the lymph nodes of the neck with a poor long term survival rate
What is the 5 year survival rate for adults with mouth cancer in England?
56%
Where is mouth cancer most commonly located?
- Tongue
- Tonsils and oropharynx
- Floor of mouth (under tongue)
What is the average size of oral cancer tumour at presentation?
3-4cm
Large! Late tumour, likely to have metastasised to lymph nodes of the neck.
What is the association between social class and mouth cancer?
- Oral cancer 3 times more common in lowest social class vs highest
- Poorer 5 year survival for those more deprived
Where is oral SCC usually found?
- Lower lip (sun exposure)
- Lateral margin of tongue
- Ventral surface of tongue
- Floor of mouth
- Lingual sulcus
- Retromolar area/fauces
75-80% of oral carcinomas occur at these sites.
Describe the possible appearance of oral SCC.
- Ulcers (granular base)
- Swellings
- Red areas
- Speckled leukoplakia
- White areas
- Firm areas (induration)
What are the clinical features of advanced SCC?
- Ulcer with raised, rolled edges
- Exophytic, nodular mass
- Reduced tongue mobility
- Pain
- Loose teeth
- Mental anaesthesia/paraesthesia
- Secondary deposits in lymph nodes
What are some aetiological factors of mouth cancer?
- Tobacco
- Alcohol
- UV light
- Diet low in fruit and veg
- Betel chewing
- Infection
- Irradiation
- Immunosuppression
Describe HPV related oropharyngeal cancer.
- Affects the tonsils, base of tongue, soft palate
- Affects younger age group than classic SCC
- Associated with HPV-16 and HPV-18
- More sensitive to chemotherapy
- Better prognosis, up to 80% 5-year survival rate
Describe the histopathology of oral SCC.
- Arises from surface epithelium
- Usually well differentiated and obviously squamous
- Invades lamina propria and underlying tissues e.g. muscle, bone, salivary glands
What term describes when cancer spreads to nerve tissue.
Perineural spread
Describe the metastasis of oral SCC.
- Cancer can invade lymphatics, nerves and blood vessels
- Secondary deposits in submandibular and cervical lymph nodes are common
- Blood borne metastases are rare but do occur
Describe oral SCC treatment.
- Surgical excision with a 5mm margin of normal tissue also removed
- Reconstruction: free tissue transfer, pedicle flaps, prosthetic
- Radiotherapy following surgical excision
- Induction chemotherapy
- Adjucant chem and radio therapy
What is the long term prognosis for a patient with oral SCC?
- Best prognosis is the lip (90%+)
- Prognosis worsens as you go further back except for HPV related oropharyngeal cancer)
- Poorly differentiated tumours have worse prognosis
- Age of patient and comorbidities
- Overall 50-60% 5-year survival
Describe salivary gland tumours.
- Relatively uncommon
- Major glands = 80-85%
- Minor glands = 15-20%
- Parotid gland most common, followed by submandibular, sublingual rare
- Minor glands: palate (55%), upper lip (20%), lower lip rare
Are parotid gland tumours more commonly malignant or benign?
- 85% benign
- 15% malignant
Which area is it common to find minor salivary gland tumours?
At the junction of the hard and soft palate.
About 45% of tumours at this site are malignant.
Describe oral pre-cancerous lesions.
- Cancer arising from pre-existing lesions of the oral mucosa
- Leukoplakia and erythroplakia
- Only a small number of pre-cancerous lesions become malignant (approx. 4% of leukoplakkia over 5-10 years)
- Aetiological factors responsible for malignant transformation may be different from those producing the original lesion
Describe erythroplakia as premalignant lesions.
- Bright red velvety plaque that cannot be characterised clinically or pathologically as any other disease
- High risk lesion, 50% become malignant over 10 years
- Red patches are more worrying than white patches
