General Information About Lip and Oral Cavity Cancer
The oral cavity extends from the skin-vermilion junctions of the anterior lips to the junction of the hard and soft palates above and to the line of circumvallate papillae below and is divided into the following specific areas:
- Anterior two thirds of tongue.
- Buccal mucosa.
- Floor of mouth.
- Lower gingiva.
- Retromolar trigone.
- Upper gingiva.
- Hard palate.
The main routes of lymph node drainage are into the first station nodes (i.e., buccinator, jugulodigastric, submandibular, and submental). Sites close to the midline often drain bilaterally. Second station nodes include the parotid, jugular, and the upper and lower posterior cervical nodes.
Precancerous lesions of the oropharynx include leukoplakia, erythroplakia, and mixed erythroleukoplakia. Leukoplakia, the most common of the three conditions, is defined by the World Health Organization as “a white patch or plaque that cannot be characterized clinically or pathologically as any other disease.” The diagnosis of leukoplakia is one of exclusion; conditions such as candidiasis, lichen planus, leukoedema, and others must be ruled out before a diagnosis of leukoplakia can be made.
The prevalence of leukoplakia in the United States is decreasing; this decline has been related to reduced tobacco consumption. Although erythroplakia is not as common as leukoplakia, it is much more likely to be associated with dysplasia or carcinoma.[1,4]
Early cancers (stage I and stage II) of the lip and oral cavity are highly curable by surgery or by radiation therapy, and the choice of treatment is dictated by the anticipated functional and cosmetic results of treatment and by the availability of the particular expertise required of the surgeon or radiation oncologist for the individual patient.[5-7] The presence of a positive margin or a tumor depth of more than 5 mm significantly increases the risk of local recurrence and suggests that combined modality treatment may be beneficial.[8,9]
Advanced cancers (stage III and stage IV) of the lip and oral cavity represent a wide spectrum of challenges for the surgeon and radiation oncologist. Except for patients with small T3 lesions and no regional lymph node and no distant metastases or who have no lymph nodes larger than 2 cm in diameter, for whom treatment by radiation therapy alone or surgery alone might be appropriate, most patients with stage III or stage IV tumors are candidates for treatment by a combination of surgery and radiation therapy. Furthermore, because local recurrence and/or distant metastases are common in this group of patients, they should be considered for clinical trials. Such trials evaluate the potential role of radiation modifiers or combination chemotherapy combined with surgery and/or radiation therapy.
Patients with head and neck cancers have an increased chance of developing a second primary tumor of the upper aerodigestive tract.[10,11] A study has shown that daily treatment of these patients with moderate doses of isotretinoin (13-cis-retinoic acid) for 1 year can significantly reduce the incidence of second tumors. No survival advantage has yet been demonstrated, however, in part due to recurrence and death from the primary malignancy. An additional trial has shown no benefit of retinyl palmitate or retinyl palmitate plus beta-carotene when compared to retinoic acid alone.[Level of evidence: 1iiDii]
The rate of curability of cancers of the lip and oral cavity varies depending on the stage and specific site. Most patients present with early cancers of the lip, which are highly curable by surgery or by radiation therapy with cure rates of 90% to 100%. Small cancers of the retromolar trigone, hard palate, and upper gingiva are highly curable by either radiation therapy or surgery with survival rates of as much as 100%. Local control rates of as much as 90% can be achieved with either radiation therapy or surgery in small cancers of the anterior tongue, the floor of the mouth, and buccal mucosa.
Moderately advanced and advanced cancers of the lip also can be controlled effectively by surgery or radiation therapy or a combination of these. The choice of treatment is generally dictated by the anticipated functional and cosmetic results of the treatment. Moderately advanced lesions of the retromolar trigone without evidence of spread to cervical lymph nodes are usually curable and have shown local control rates of as much as 90%; such lesions of the hard palate, upper gingiva, and buccal mucosa have a local control rate of as much as 80%. In the absence of clinical evidence of spread to cervical lymph nodes, moderately advanced lesions of the floor of the mouth and anterior tongue are generally curable with survival rates of as much as 70% and 65%, respectively.[13,14]
Other PDQ summaries containing information related to lip and oral cavity cancer include the following:
- Neville BW, Day TA: Oral cancer and precancerous lesions. CA Cancer J Clin 52 (4): 195-215, 2002 Jul-Aug. [PUBMED Abstract]
- Kramer IR, Lucas RB, Pindborg JJ, et al.: Definition of leukoplakia and related lesions: an aid to studies on oral precancer. Oral Surg Oral Med Oral Pathol 46 (4): 518-39, 1978. [PUBMED Abstract]
- Scheifele C, Reichart PA, Dietrich T: Low prevalence of oral leukoplakia in a representative sample of the US population. Oral Oncol 39 (6): 619-25, 2003. [PUBMED Abstract]
- Shafer WG, Waldron CA: Erythroplakia of the oral cavity. Cancer 36 (3): 1021-8, 1975. [PUBMED Abstract]
- Cummings CW, Fredrickson JM, Harker LA, et al.: Otolaryngology - Head and Neck Surgery. Saint Louis, Mo: Mosby-Year Book, Inc., 1998.
- Harrison LB, Sessions RB, Hong WK, eds.: Head and Neck Cancer: A Multidisciplinary Approach. 3rd ed. Philadelphia, PA: Lippincott, William & Wilkins, 2009.
- Wang CC, ed.: Radiation Therapy for Head and Neck Neoplasms. 3rd ed. New York: Wiley-Liss, 1997.
- Jones KR, Lodge-Rigal RD, Reddick RL, et al.: Prognostic factors in the recurrence of stage I and II squamous cell cancer of the oral cavity. Arch Otolaryngol Head Neck Surg 118 (5): 483-5, 1992. [PUBMED Abstract]
- Po Wing Yuen A, Lam KY, Lam LK, et al.: Prognostic factors of clinically stage I and II oral tongue carcinoma-A comparative study of stage, thickness, shape, growth pattern, invasive front malignancy grading, Martinez-Gimeno score, and pathologic features. Head Neck 24 (6): 513-20, 2002. [PUBMED Abstract]
- Day GL, Blot WJ: Second primary tumors in patients with oral cancer. Cancer 70 (1): 14-9, 1992. [PUBMED Abstract]
- van der Tol IG, de Visscher JG, Jovanovic A, et al.: Risk of second primary cancer following treatment of squamous cell carcinoma of the lower lip. Oral Oncol 35 (6): 571-4, 1999. [PUBMED Abstract]
- Papadimitrakopoulou VA, Lee JJ, William WN Jr, et al.: Randomized trial of 13-cis retinoic acid compared with retinyl palmitate with or without beta-carotene in oral premalignancy. J Clin Oncol 27 (4): 599-604, 2009. [PUBMED Abstract]
- Wallner PE, Hanks GE, Kramer S, et al.: Patterns of Care Study. Analysis of outcome survey data-anterior two-thirds of tongue and floor of mouth. Am J Clin Oncol 9 (1): 50-7, 1986. [PUBMED Abstract]
- Takagi M, Kayano T, Yamamoto H, et al.: Causes of oral tongue cancer treatment failures. Analysis of autopsy cases. Cancer 69 (5): 1081-7, 1992. [PUBMED Abstract]