Surgery for Different Oral Cavity Sites

 

Numerous studies have reported five-year overall survival rates of 95 and 85 percent for early stage I and II oral cancers respectively6-8. In this section, I will outline the principles of management for different oral subsites:

 

The Lower Lip

Squamous cell carcinomas occur more commonly than basal cell carcinomas in the lower lip mainly as a result of chronic UV radiation. Lymph node metastasis to the neck is rare unless the tumour is thick.

One study has suggested that a mean tumour thickness of 5.6mm vs 3.8mm would be more likely to result in lymph node metastasis to the neck1.

As the study only included 27 patients the prognostic significance of this is uncertain.

In general, neck dissection is not required for T1 lower lip cancers. For T2 and larger cancers dissection of levels IA and IB should be considered as it is rare for lip cancers to metastasize to lower neck levels without first invading the facial, submental and submandibular lymph nodes 2.

 

Upper Lip

Cancers which arise from the upper lip and or commissure generally have a worse prognosis than the lower lip. These tumours tend to grow rapidly with invasion of the premaxilla or nasal tissues and are associated with spread to local cervical lymph nodes *25-27). Surgical resection may be complex because of the involvement of bone and need for functional as well as aesthetic reconstruction. Most defects which involve less than two thirds of the upper lip may be closed primarily whilst larger defects (up to three quarters) may be reconstructed Karapandzic 3 or Abbe-Estlander flaps.4

 

Prognosis for Lip Cancer 

This is generally good with the literature reporting 10-year recurrence-free survival rates of 94 and 78 percent for stage I and II disease respectively5 .

 

The Floor of Mouth

Early stage floor of mouth cancers can generally be excised with preservation of the lingual nerve, if oncologically possible. Defects may be closed primarily, covered with a skin graft or free vascularised tissue such as the radial forearm free flap. Early metastasis to the neck is common with midline tumours necessitating evaluation of both sides of the neck for treatment.

 

Tongue Cancer

I recommend surgery for tongue cancer where good function can be preserved. En-bloc partial glossectomy with or without Reconstruction can preserve speech and swallowing in early stage I and II disease with most patients returning to work in a phased manner around three months after surgery.

Historically, management of the neck in early tongue cancer has been controversial, however, it is now generally accepted that the majority of patients presenting with tumors equal to or greater than 3mm depth of invasion should have surgery in the form of a selective neck dissection incorporating neck levels one to four 9.

 

Buccal Mucosa Cancer

Buccal mucosal cancers rarely present early as they are often misdiagnosed as infection or trauma. The thin buccal mucosa allows access to the buccal space and muscle where tumours may invade deeply. Local spread to facial lymph nodes is common with particular emphasis on this area during surgery. Reconstruction may be challenging as the lining of the mouth, mandible, parotid gland and skin may be involved in an oncologically safe en-bloc resection. The radial forearm free flap provides abundant soft tissue and/or bone for oral rehabilitation post operatively. Trismus may be problematic after treatment which often includes adjuvant chemo-radiotherapy  because of the high recurrence rates 10and thus, jaw opening exercises, carried out in a long term basis will be required to maintain mouth opening.

 

Prognosis for buccal mucosal cancer

For early stage I disease three year disease survival rates of 75-85 percent have been reported with 65 percent for stage II cancers 11-14.

 

Lower Alveolar Ridge and Retromolar trigone Cancer

The retromolar trigone is a triangular region of tissue which sits just behind the lower third molar extending upwards to the maxillary tuberosity, soft palate and anterior tonsillar pillar on the medial aspect, with continuity with the gingivae and buccal mucosa on the lateral aspect.

Small tumours may therefore invade deeply into a number of soft tissue regions as well as the bone of the mandible and hence the incidence of occult lymph node metastasis is high 15-17.

Surgical treatment involves en-bloc resection and rim resection of the mandible as a marginal tissue plane. Where there is evidence of direct invasion of bone, segmental resection of the mandible will be necessary.

 

Prognosis for retromolar/lower alveolar ridge tumours

The five-year disease-free survival rate for this tumour group is approximately 70 percent 18-20.

 

Upper Alveolar Ridge/ Maxillary Cancers

Management is similar to lower alveolar ridge cancers with reconstruction based on the size of the defect. For large defects I prefer biological reconstruction rather than a prosthesis which does have a use in certain patient groups.

 
Further Reading
  1. McCombe D, MacGill K, Ainslie J, et al. Squamous cell carcinoma of the lip: a retrospective review of the Peter MacCallum Cancer Institute experience 1979-88. Aust N Z J Surg 2000; 70:358.
  2. Schantz SP, Harrison LB, Forasteriere AA. Tumors of the nasal cavity and paranasal sinuses, nasopharynx, oral cavity, and oropharynx. In: Cancer: Principles and Practice of Oncology, 5th, Devita VT Jr, Hellman S, Rosenberg, SA (Eds), Lippincott-Raven, Philadelphia 1997. p.753.
  3. Hanasono MM, Langstein HN. Extended Karapandzic flaps for near-total and total lower lip defects. Plast Reconstr Surg 2011; 127:1199.
  4.  Coppit GL, Lin DT, Burkey BB. Current concepts in lip reconstruction. Curr Opin Otolaryngol Head Neck Surg 2004; 12:281.
  5. McCombe D, MacGill K, Ainslie J, et al. Squamous cell carcinoma of the lip: a retrospective review of the Peter MacCallum Cancer Institute experience 1979-88. Aust N Z J Surg 2000; 70:358.
  6. Hicks WL Jr, Loree TR, Garcia RI, et al. Squamous cell carcinoma of the floor of mouth: a 20-year review. Head Neck 1997; 19:400.
  7. Matsumoto S, Takeda M, Shibuya H, Suzuki S. T1 and T2 squamous cell carcinomas of the floor of the mouth: results of brachytherapy mainly using 198Au grains. Int J Radiat Oncol Biol Phys 1996; 34:833.
  8. Rodgers LW Jr, Stringer SP, Mendenhall WM, et al. Management of squamous cell carcinoma of the floor of mouth. Head Neck 1993; 15:16.
  9. Byers RM, Weber RS, Andrews T, et al. Frequency and therapeutic implications of “skip metastases” in the neck from squamous carcinoma of the oral tongue. Head Neck 1997; 19:14.
  10. Strome SE, To W, Strawderman M, et al. Squamous cell carcinoma of the buccal mucosa. Otolaryngol Head Neck Surg 1999; 120:375.
  11. Nair MK, Sankaranarayanan R, Padmanabhan TK. Evaluation of the role of radiotherapy in the management of carcinoma of the buccal mucosa. Cancer 1988; 61:1326.
  12. Dixit S, Vyas RK, Toparani RB, et al. Surgery versus surgery and postoperative radiotherapy in squamous cell carcinoma of the buccal mucosa: a comparative study. Ann Surg Oncol 1998; 5:502.
  13. Diaz EM Jr, Holsinger FC, Zuniga ER, et al. Squamous cell carcinoma of the buccal mucosa: one institution’s experience with 119 previously untreated patients. Head Neck 2003; 25:267.
  14. Iyer SG, Pradhan SA, Pai PS, Patil S. Surgical treatment outcomes of localized squamous carcinoma of buccal mucosa. Head Neck 2004; 26:897.
  15. Tsue TT, McCulloch TM, Girod DA, et al. Predictors of carcinomatous invasion of the mandible. Head Neck 1994; 16:116.
  16. Hao SP, Tsang NM, Chang KP, et al. Treatment of squamous cell carcinoma of the retromolar trigone. Laryngoscope 2006; 116:916.
  17. Cleary KR, Batsakis JG. Oral squamous cell carcinoma and the mandible. Ann Otol Rhinol Laryngol 1995; 104:977.
  18. Mendenhall WM, Morris CG, Amdur RJ, et al. Retromolar trigone squamous cell carcinoma treated with radiotherapy alone or combined with surgery. Cancer 2005; 103:2320.
  19. Byers RM, Newman R, Russell N, Yue A. Results of treatment for squamous carcinoma of the lower gum. Cancer 1981; 47:2236.
  20. Huang CJ, Chao KS, Tsai J, et al. Cancer of retromolar trigone: long-term radiation therapy outcome. Head Neck 2001; 23:758.