Buccal Carcinoma of the Head and Neck

Surgical anatomy of the buccal region

• The buccal mucosa:
  • Is the mucosal lining of the inner surface of the cheek
  • The area extends from:
    • The oral commisure anteriorly to the retromolar trigone posteriorly:
      • The junction between the buccal mucosa and retromolar trigone:
        • Is an arbitrary line drawn from the maxillary tuberosity to the distobuccal aspect of the mandibular third molar (or its anticipated position if not present)
  • The inferior and superior boundaries of the area are delineated by:
    • The mandibular and maxillary gingivobuccal sulci, respectively
• The buccal mucosa is not exposed to masticatory loads:
  • So is covered by a lining mucosa with nonkeratinizing stratified squamous epithelium:
    • The mucosa is firmly attached to the underlying buccinator muscle
    • Minor salivary glands are located within the cheek (submucosa)
• The parotid duct:
  • Pierces the buccinator muscle to enter the oral cavity adjacent to the second maxillary molar tooth
• Sensory innervation to the area:
  • Is via the buccal branch of the mandibular division of the trigeminal nerve
• Lymphatic drainage of the site:
  • Is via the ipsilateral facial and submandibular nodes:
    • To the deep cervical chain
• The thickness of the cheek, from mucosal lining to external skin:
  • Is 1 cm to 3 cm
• Epidemiology
  • The buccal mucosa is the most common site for oral cancer:
    • In South East Asia:
      • Up to 40% of oral cancers arising at this site
    • This contrasts with North America and Western Europe:
      • Where buccal carcinoma only accounts for 2% to 10% of oral carcinomas
  • The consumption of betel quid:
    • Is socially and culturally embedded in the countries of South East Asia:
      • It is responsible for the difference in site predilection
    • The ingredients of betel quid (paan / paan masala) varies throughout South East Asia:
      • The main ingredients include:
        • The piper betel leaf
        • Slaked lime
        • Spices
        • Tobacco
        • Areca nut
    • For many years, the tobacco content alone was credited as being the carcinogenic agent in betel quid:
      • However it is now recognized that the areca nut is also carcinogenic:
        • As well as being the main etiological agent in:
          • Oral submucous fibrosis
      • Individuals who consume betel quid frequently have a preference regarding which side they chew betel:
        • This corresponding to the side of tumor development
      • There is a strong association with smoking and alcohol consumption:
        • In populations where betel chewing is not prevalent
• The male-to-female ratio:
  • In Western countries approximates 1:1:
    • However in South East Asia the ratio reflects the consumption of betel quid
  • In India, the male-to-female ratio is approximately 4:1
  • In the Taiwanese population, where betel quid use occurs primarily in the male population:
    • The ratio may be as high as 27:1
• Buccal carcinoma typically occurs over the age of 40 years:
  • Although it may occur in younger patients:
    • Particularly when associated with the habit of betel chewing
• Presentation:
  • Buccal carcinoma may be described as:
    • Verrucous, exophytic or ulceroinfiltrative in character

• Presentation of buccal carcinoma of the oral cavity:
  • Patients may present with:
    • Pain
    • An intraoral mass
    • Ulceration
    • Trismus
  • Patients who chew betel often have areas of:
    • Erythroleukoplakia of the buccal mucosa or submucous fibrosis and consequent trismus:
      • Making the detection of invasive squamous cell carcinoma difficult
  • Advanced buccal carcinomas may extend into adjacent sites to include:
    • External skin, mandible or maxilla
  • It is not unusual for patients to present with advanced disease:
    • 40% or more presenting with stage III / IV disease
    • Palpable lymphadenopathy on presentation:
      • May be as high as 57% for T3 / T4 lesions
    • Occult nodal metastasis:
      • May be present in 26% of those who are clinically N0 at presentation:
        • Tumors greater than T2, are poorly differentiated, have a poor lymphocytic response or are thicker than 5 mm:
          • Are more likely to demonstrate cervical metastasis
      • Tumors are usually well differentiated
• Work up:
  • Biopsies of buccal carcinomas should be of sufficient depth to help the pathologist give an indication of depth of invasion:
    • Since this will help decide on management of the neck
  • Buccal carcinoma may rapidly extend to adjacent sites:
    • Thus accurate imaging is required:
      • Most patients will require MRI / CT imaging:
        • Augmented with ultrasound scan if necessary to help in the assessment of depth of primary and cervical lymphadenopathy
• Treatment
  • Primary site:
    • Traditional treatment of buccal carcinoma is:
      • Surgery with postoperative radiation therapy (PORT) for selected patients
    • T1 / T2 disease:
      • Can typically be resected perorally
    • T3 / T4 disease:
      • May require facial access incisions and bony resection of the maxilla and / or mandible
    • The primary tumor should be resected with:
      • A 1 cm margin and up to 2 cm if skin is involved
      • The buccinator muscle:
        • Should be included as the deep margin at the very least
      • The parotid duct:
        • May need to be repositioned or ligated
      • External skin should be taken with the specimen:
        • If there is any evidence clinically or on imaging that it is involved
      • Partial maxillectomy or mandibular resection (rim (marginal) or segmental) may be required.
    • Small T1 tumors:
      • May be resected and reconstructed by primary closure
      • Healing by secondary intention may be considered:
        • However postoperative trismus may be anticipated:
          • Unless vigorous mouth opening exercises are conducted
      • Split thickness skin grafts may be used:
        • The use of silicone sheets to stabilize the graft being useful
        • The use of a skin graft to reconstruct deeper resections:
          • May leave a very thin cheek with potentially poor aesthetics
      • Local flaps such as:
        • The buccal fat pad or temporoparietal fascial flap:
          • May be used for reconstruction if tumor extension does not compromise their use
      • Microvascular free flap reconstruction with a radial free forearm flap or anterolateral thigh flap:
        • Restores the thickness of the cheek and if external skin is involved:
          • The flaps can be bipaddled to provide reconstruction of mucosal and skin surfaces
    • T4 tumors requiring segmental resection of the mandible:
      • May require composite free flap reconstruction
    • Reconstruction with a radial free forearm flap:
      • Has been shown to give better postoperative mouth opening than reconstruction with a split skin graft or buccal fat pad

• Radiotherapy:
  • As a single treatment modality for T1 / T2 tumors has been advocated:
    • However, a change of practice from radiotherapy to surgery at Memorial Sloan Kettering Cancer Center was associated with improved prognosis
  • Brachytherapy or external beam irradiation may be considered
• Management of the Neck:
  • Regional spread of disease in buccal carcinoma is usually to:
    • The ipsilateral level I and II lymph nodes
  • Patients with palpable lymphadenopathy or pathological nodes on imaging:
    • Should have a comprehensive neck dissection:
      • Although if pathological nodes are only located in level I, a level I to III selective neck dissection (SND) may be considered
    • Nodes in the region of the facial artery as it crosses the mandible:
    • Should be removed with the neck dissection specimen
  • Patients with a cN0 neck:
    • With a T2 or greater primary tumors or tumors with a thickness greater than 5 mm:
      • Should have an elective neck dissection:
        • Some institutions will conduct an elective neck dissection (END) if the tumor is 3 to 4 mm thick or if histological examination of the tumor demonstrates lymphatic infiltration
• PORT:
  • The indications for postoperative radiotherapy to the loco-regional area are similar to other sites:
    • Notably two or more nodes in the neck, extracapsular spread (ECS), positive margins or stage III / IV disease
  • The beneficial role of PORT in selected patients with buccal carcinoma has been demonstrated by several authors:
    • Some authors suggest that PORT should be considered even in stage I and II disease, or tumors greater than 10 mm thick
• Recurrence:
  • Recurrence rates for buccal carcinoma are 26% to 80%:
    • Usually occurring within two years
  • Involvement of the parotid duct and buccinator:
    • Have not been found to be significant indicators of recurrence
  • Factors that influence recurrence include:
    • Tumor thickness and tumor differentiation