Patients staged N0
The regional lymph nodes, although clinically im-palpable, sometimes contain occult foci of malig-nant cells. It seems reasonable to expect that removal or treatment of regional lymph nodes, even when clini-cally clear, would improve cure rates. Alternatively, it can be argued that treatment of the regional nodes in all cases is unnecessary, because only a minority have metastases in the nodes. In practice, whenever the surgery for the primary cancer involves opening the neck, a prophylactic neck dissection is under taken.
The submandibular triangle often must be opened as part of the resection of the primary, and therefore a function-sparing elective neck dissection for tumours in the fl oor of the mouth, lower alveolar ridge and tongue is advocated. In this dissection, struc tures such as the accessory nerve, internal jugular vein and sternocleidomastoid muscle are preserved.
The operation should preferably be seen as a staging procedure on which is based the decision to give Fig. 10.13 Implants within a reconstructed mandible,
following resection for carcinoma.
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Nodal metastasis appearing after primary treatment
Provided that follow-up at regular intervals is rigorously maintained, it should be possible to detect a lymph node metastasis while it is still relatively small and therefore operable. Ultrasound-guided fine-needle aspiration cytology is particularly useful in this situation to confirm that the palpable node is a carcinoma rather than being enlarged due to reactive hyperplasia. Whenever positive, or if there is any doubt, a radical neck dissection is performed, followed by external irradiation if multiple involved nodes or extracapsular spread are found.
FOLLOW-UP
Approximately 50% of patients treated for oral cancer will die from the disease, approximately 20%
of patients will develop a local recurrence at the site of the primary tumour; another 25% will develop nodal metastases. Both of these events are likely to occur within the first 2 years following treatment.
A further 20% of patients with oral cancers will develop additional new cancers elsewhere in the upper aerodigestive tract due to field changes resulting from tobacco and alcohol abuse. For all these reasons careful and meticulous follow-up is essential. For the first 12 months following treatment the patient will be seen at the hospital monthly.
During the second year the patient is seen at 2- to 3-month intervals and thereafter they are seen every 6 months.
The general dental practitioner has an ongoing role in monitoring and treating dental diseases, which might impact on the tissues treated because of cancer and in observing for any new malignant disease.
radical postoperative radiotherapy. All patients with two or more positive nodes or extracapsular spread should be treated with postoperative radiotherapy.
Patients staged N1, N2a, N2b
Present evidence suggests that the treatment of choice is a full neck dissection wherever possible sparing the sternocleidomastoid muscle, the accessory nerve and the internal jugular vein, either alone or combined with postoperative radiotherapy if multiple nodal involvement or extracapsular extension is found in the resected specimen. In patients unfit for radical surgery, radical external beam irradiation is indicated.
Patients staged N2c
It is uncommon for patients with oral cancer to present with bilateral nodes. When they do so, there is often a large inoperable primary tumour, which is best treated by external radiation. It therefore seems logical to treat the neck also by irradiation. Occasionally, particularly in a young patient, bilateral neck dissection can be justified. A full radical neck dissection is undertaken on the ipsilateral side and the internal jugular vein is spared if possible on the contralateral side. Most often postoperative radiotherapy will be required for multiple nodal involvement or extra-capsular spread. In such situations, severe post-treatment oedema or congestion of the face and tongue may be anticipated.
Patients staged N3
N3 indicates massive involvement, usually with fixation. Large fixed nodes are often associated with advanced primary disease with a poor prognosis.
Surgery is not normally advisable: removal of the common or internal carotid artery with replacement, or extensive resection, of the base of the skull, although technically feasible, is seldom advisable.
Treatment is most often by external radiotherapy. In a few younger patients with resectable primaries it is worth rendering a fixed mass in the neck operable by preoperative radiotherapy.
Role of the general dental practitioner following treatment
● Regular 6-monthly monitoring for life
● Early attention to all new caries or periodontal disease
● Continuing use of fl uoride mouthwash indefinitely
● Urgent referral of patient if any suspicion of recurrence or new cancer
● Absolute avoidance of dental extractions or surgery in patients who have received radiotherapy
FOLLOW-UP
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10 / Malignant disease of the oral cavity
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(b) A 3-cm diameter squamous cell carcinoma of the fl oor of mouth (Fig. 10.14), involving the alveolus and with several positive nodes on the same side of the neck.
(c) Widespread erythroplakia of both cheeks, fl oor of the mouth and lips, with multiple early invasive squamous cell carcinomas.
4. What is the role of the dental practitioner following treatment for oral cancer?
5. What are the principal drawbacks of surgery and radiotherapy for the management of oral cancer?
Answers on page 266.
SELF-ASSESSMENT FURTHER READING
Kramer I. R. H., El-Laban N., Lee K. W. (1978) The clinical features and risk of malignant transformation in sublingual keratosis. British Dental Journal 144: 171–180.
Langdon J. D., Henk J. M. (1995) Malignant tumours of the mouth, jaws and salivary glands. Edward Arnold, London.
Ord R. A., Blanchaert R. H. (1999) Oral cancer. The dentist’s role in diagnosis, management, rehabilitation and prevention.
Quintessence, Chicago, IL.
Pindborg J. J. (1980) Oral cancer and precancer. Wright, Bristol, UK.
1. What are the principal risk factors for the development of squamous cell carcinoma of the mouth and oropharynx?
2. How do the following compare with respect to their risk of malignant change?
(a) Leukoplakia (b) Erythroplakia (c) Submucous fibrosis (d) Lichen planus
3. How are the following cancers likely to be treated?
(a) A 1-cm diameter squamous cell carcinoma of the tip of the tongue in an otherwise fit 60-year-old person.
Fig. 10.14 See question 3.
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