See also the separate dedicated article Cancers of the Head and Neck.
Most cancers of the head and neck are squamous cell carcinomas (SCCs). About one third of oral cancers are diagnosed in the mouth cavity and a similar proportion on the tongue. Lip cancer is the least frequent type of oral cancer. Oral cavity cancer includes tumours of the:
- Buccal mucosa.
- Retromolar triangle.
- Hard palate.
- Anterior two-thirds of the tongue.
- Floor of the mouth.
- Mucosal surface of the lip.
Oral mucosal melanomas may occur, particularly affecting the palate, alveolar gingivae and lips. Virtually any malignancy can metastasise to the oral cavity but carcinomas of the breast, lung, kidney and adrenal gland are the most common.
Early detection and treatment are critical, as they increase survival chances considerably, allow for simpler treatment and result in a better quality of life for survivors.
- In 2007, the UK incidence figures (per 100,000 population) were:
- All oral cavity cancers: 7.6 (males 10.9; females 4.6).
- Mouth: 2.3 (males 3.0; females 1.6).
- Tongue: 2.3 (males 3.2; females 1.5).
- Lip: 0.3 (males 0.5; females 0.2).
- Mouth cancer is more likely to affect people over 40 years of age, although an increasing number of young people are developing the condition - especially women.
- 50 years ago mouth cancer was 5 times more common in men than women - now it is only twice as common, as more and more women are diagnosed.
- In India the incidence rate approaches 50% of all cancers (male incidence rates up to 6.5 per 100,000 per annum).
- In Europe the incidence of oral cavity cancer is very low, accounting for less than 5% of all cancers; however, in France (male incidence rates up to 8 per 100,000 per annum), it is the third most common cancer in males and the second most common cause of death from cancer.
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- Heavy smoking (or chewing tobacco products), heavy alcohol consumption and poor dentition are the principle risk factors in western countries.
- There is increasing evidence which shows that oral sex can be a contributory factor in passing on the disease, via the transmission of the human papillomavirus (HPV) which can be found in the lining of the mouth and throat, the cervix and the anus. HPV has been detected in various amounts in persons with oral dysplasia, leukoplakia and malignancy.
- Paterson Brown-Kelly syndrome (Plummer-Vinson syndrome), which includes iron deficiency, has been associated with an increased risk of cancer of the oral cavity. Increasing amounts of data suggest that vitamins A and C, along with the carotenoids, may be protective against epithelial cancers.
- Excessive sunlight exposure is associated with melanoma of the lip.
Although there is evidence that a visual examination as part of a population-based screening programme reduces the mortality rate of oral cancer in high-risk individuals, there is otherwise little evidence to support any screening programme for early detection of oral cavity cancers.
- Malignancies of the tongue may grow to significant size before they cause symptoms.
- Approximately 75% occur in the mobile tongue:
- They are often well-differentiated. The cancer may spread easily and become symptomatic only when its size interferes with movement:
- Squamous cell carcinoma (SCC) of the tongue may arise in apparently normal epithelium, in areas of leukoplakia, or in an area of chronic glossitis. These lesions are usually larger than 2 cm at presentation, with the lateral border being the most common site.
- The macroscopic appearance of these lesions depends on the duration of the lesion, the amount of keratinisation, and the changes in the adjoining mucosa. A fully developed lesion has the appearance of an exophytic bulky lesion that is grey to greyish-red and has a rough, shaggy, or papillomatous surface.
- The patient may develop speech and swallowing dysfunction.
- Pain occurs when the tumour involves the lingual nerve, and this pain may also be referred to the ear.
- Carcinomas of the tongue base:
- These are clinically silent until they deeply infiltrate the tongue musculature. They are usually less differentiated.
- Because of the difficulties with direct visualisation, they may extend into the oral tongue or have clinical lymph metastases before the diagnosis is established.
More than 70% of tonsillar cancers are SCC. Most of the others are lymphomas. Metastases to the palatine tonsils are rare, but there have been reports of secondaries from breast, lung, renal, pancreatic and colorectal malignancies.
- Patients with tonsillar carcinomas may present with a neck mass, usually in the jugulodigastric region. Even if the neck mass is not evident on casual inspection, careful palpation may reveal cervical lymphadenopathy.
- Sore throat, ear pain, foreign body or mass sensation, and bleeding may occur.
- Trismus is an ominous sign because it probably indicates involvement of the parapharyngeal space. Such tumours may be large enough to involve or encase the carotid sheath. In addition, the tumour may extend to the skull or mediastinum.
- If the tumour has involved the tongue base, contralateral nodes may be involved.
- Primary tonsillar tumours may grow entirely beneath the surface. The clinician may therefore see nothing suspicious or may see only a slight increase in the size of the tonsil or the firmness of the area.
- Alternatively, an exophytic fungating mass with central ulceration and heaped-up edges may be present. It may be deep red to white.
- Weight loss and fatigue are not uncommon.
- Treatment may lead to pain, xerostomia, infections, poor wound healing, dysphagia, fistula formation, trismus, potential disfigurement and fatigue.
Buccal mucosa cancer
- The tumour is usually at the level of the occlusal plane or below it.
- The lesion is usually painless in the early stages and, only when it becomes ulcerated and secondarily infected or invades an adjacent nerve, is pain the noticeable feature.
- This may be followed by bleeding and difficulty chewing.
- They may be proliferative warty exophytic growth with little fixation, or deeply ulcerative invasive lesion.
- The proliferative lesion, although it looks dangerous, is easily treatable and long-term prognosis is good, as the metastasis to the local lymph nodes is relatively late.
- In contrast, the ulcerative lesion (which is not so easily noticeable in the early stages) is more dangerous because of its invasive nature and very early metastasis to the local lymph nodes.
The 'tumour, nodes, metastases' (TNM) staging system is used for staging head and neck cancers. T is the extent of the primary tumour; N is the involvement of regional lymph nodes; M is the presence of metastases. The depth of infiltration is predictive of prognosis.
T - primary tumour
- TX - primary tumour cannot be assessed.
- T0 - no evidence of primary tumour.
- Tis - pre-invasive cancer (carcinoma in situ).
- T0 - no evidence of primary tumour.
- T1 - tumour 2 cm or less in greatest dimension.
- T2 - tumour larger than 2 cm but not larger than 4 cm.
- T3 - tumour larger than 4 cm.
- T4a - through cortical bone, deep/extrinsic muscle of tongue, maxillary sinus, skin.
- T4b - masticator space, pterygoid plates, skull base, internal carotid artery.
The N and M staging definitions are the same for all areas of the upper aerodigestive tract and are outlined in the Cancers of the Head and Neck separate article.
- Altered fractionation radiotherapy is associated with an improvement in overall survival and locoregional control in patients with oral cavity and oropharyngeal cancers.
- Chemotherapy, in addition to radiotherapy and surgery, is associated with improved overall survival in patients with oral cavity and oropharyngeal cancers. There is some evidence that combined radiotherapy and chemotherapy with surgery is more effective than radiotherapy alone with surgery and may benefit outcomes in patients with more advanced oral and oropharyngeal cancers.
Early oral cavity cancer
- Surgical resection, or brachytherapy in accessible well demarcated lesions. Re-resection should be performed to achieve clear histological margins if the initial resection has positive surgical margins.
- Clinically, N0 neck disease (levels I-III) should be treated prophylactically either by external beam radiotherapy or selective neck dissection (NB: the neck lymph node levels I-VI are defined in the separate article Cancers of the Head and Neck).
- Postoperative radiotherapy should be considered for patients who have positive nodes after pathological assessment.
- Concurrent administration of cisplatin chemotherapy with postoperative radiotherapy should be considered, especially in patients with extracapsular spread and/or positive surgical margins.
Advanced oral cavity cancer
- Patients with resectable disease who are fit for surgery should have surgical resection with reconstruction.
- Patients with node-positive disease should be treated by modified radical neck dissection.
- Elective dissection of the contralateral neck should be considered if the primary tumour is locally advanced, arises from the midline or if there are multiple ipsilateral nodes involved.
- Radical external beam radiotherapy with concurrent cisplatin chemotherapy should be considered when the tumour cannot be adequately resected, the patient's general condition precludes surgery, the patient does not wish to undergo surgical resection, or when nodal levels I-IV should be irradiated bilaterally.
- Patients with lymph node involvement should be treated with chemoradiotherapy followed by:
- N1 nodal disease: neck dissection where there is clinical evidence of residual disease following completion of therapy.
- N2 and N3 nodal disease: planned neck dissection.
- In patients medically unsuitable for chemotherapy, concurrent administration of cetuximab with radiotherapy should be considered.
- Postoperative radiotherapy should be considered for patients with clinical and pathological features that indicate a high risk of recurrence.
- Administration of cisplatin chemotherapy concurrently with postoperative radiotherapy should be considered, especially in patients with extracapsular spread and/or positive surgical margins.
For T1 and T2 lesions, radiotherapy using interstitial implants with or without external beam radiotherapy and surgical excision have equivalent results:
- The 5-year disease-free survival rate ranges from 80-90% for lesions treated with either modality (the long-term complications of radiation implants, including local necrosis and bone exposure, are more frequent than those associated with surgery).
- The 5-year survival rates for patients in stages III and IV are 30-50%, decreasing to 15-30% in patients with lymph node metastasis.
- The 5-year survival rate of treated squamous cell carcinoma (SCC) of the tonsillar region is 80% for stage I but 30% for stage IV.
- Patients with HPV-positive tumours have improved survival.
Cancer of the buccal mucosa
- The overall reported 5-year survival rates for buccal carcinoma are between 49% and 68%.
- About 90% of recurrences occur within the first 1.5 years after treatment. Local recurrence (reported rate 23%) is more common than regional recurrence (reported rate of 11%). Distant metastases are uncommon in buccal carcinoma.
Further reading & references
- Scully C, Bagan JV; Recent advances in oral oncology 2008; squamous cell carcinoma imaging, treatment, prognostication and treatment outcomes. Oral Oncol. 2009 Jun;45(6):e25-30. Epub 2009 Feb 26.
- Ayllon Barbellido S, Campo Trapero J, Cano Sanchez J, et al; Gene therapy in the management of oral cancer: review of the literature. Med Oral Patol Oral Cir Bucal. 2008 Jan 1;13(1):E15-21.
- National Cancer Institute (US); Lip and Oral Cavity Cancer Treatment
- Oral cancer - UK incidence statistics, Cancer Research UK
- Diagnosis and management of head and neck cancer, Scottish Intercollegiate Guidelines Network - SIGN (2006)
- Shiboski CH, Schmidt BL, Jordan RC; Tongue and tonsil carcinoma: increasing trends in the U.S. population ages 20-44 years. Cancer. 2005 May 1;103(9):1843-9.
- Muir C, Weiland L; Upper aerodigestive tract cancers. Cancer. 1995 Jan 1;75(1 Suppl):147-53.
- Gosselin EJ; Malignant Tumors of the Mobile Tongue, eMedicine, May 2009
- Graham S, Dayal H, Rohrer T, et al; Dentition, diet, tobacco, and alcohol in the epidemiology of oral cancer. J Natl Cancer Inst. 1977 Dec;59(6):1611-8.
- Andrews E, Seaman WT, Webster-Cyriaque J; Oropharyngeal carcinoma in non-smokers and non-drinkers: a role for HPV. Oral Oncol. 2009 Jun;45(6):486-91. Epub 2008 Nov 21.
- Brocklehurst P, Kujan O, Glenny AM, et al; Screening programmes for the early detection and prevention of oral cancer. Cochrane Database Syst Rev. 2010 Nov 10;11:CD004150.
- Scully C, Cancers of the Oral Mucosa, Medscape, Apr 2012
- Kelley DJ, Malignant Tumors of the Base of Tongue, eMedicine, Nov 2008
- Glenny AM, Furness S, Worthington HV, et al; Interventions for the treatment of oral cavity and oropharyngeal cancer: Cochrane Database Syst Rev. 2010 Dec 8;12:CD006387.
- Furness S, Glenny AM, Worthington HV, et al; Interventions for the treatment of oral cavity and oropharyngeal cancer: Cochrane Database Syst Rev. 2010 Sep 8;(9):CD006386.
- Oliver RJ, Clarkson JE, Conway DI, et al; Interventions for the treatment of oral and oropharyngeal cancers: surgical Cochrane Database Syst Rev. 2007 Oct 17;(4):CD006205.
- Kokat N; Malignant Tumours of the Tonsil, Surgical Treatment, eMedicine, Sep 2010
- Klem C et al; Buccal Carcinoma, eMedicine, Jun 2010
|Original Author: Dr Hayley Willacy||Current Version: Dr Colin Tidy|
|Last Checked: 18/03/2011||Document ID: 3941 Version: 3||© EMIS|
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