Oropharyngeal Cancer
Oral cancer – What is it?
Cancer is the second leading cause of death after cardiovascular disease and cancer of the oral cavity and pharynx accounts for 2.5% of all cases. Although oral and pharyngeal cancer is one of the most preventable of all cancers, the mortality rates are very high. The fact that it is most amenable to early detection emphasizes the importance of the clinician’s knowledge of risk factors and clinical manifestations for oral cancer.

Risk factors of Oropharyngeal cancer
Tobacco and alcohol have long been identified as major risk factors for oropharyngeal cancer and they may account for approximately three–quarters of all oropharyngeal cancers. The risk increases significantly when the heavy consumption of alcohol and smoking are combined. Some specifics on the risks of using tobacco are as follows:

• An increased risk of oropharyngeal cancer among both filter and non–filter cigarette, pipe, and cigar smokers, with the non–filter smokers experiencing twice the risk as filter smokers.
• Smokeless tobacco significantly increases the risk of oropharyngeal cancer.
• Sharp decreases in the risk of oropharyngeal cancer follow smoking cessation.
• Alcohol rules carcinogenic potential of tobacco in several ways: nutritional deficiencies associated with heavy drinking, the effects of contaminants and congeners in alcoholic beverages, the induction of microsomal enzymes that enhance the metabolic activation of tobacco or other carcinogens, and the capacity of alcohol to solubilise carcinogens or enhance their penetration in oropharyngeal tissues.
• Alcohol may also promote the deleterious effects of other possible cancer–causing factors such as oncogenic viruses (eg. human papillomavirus), sunlight (in the case of lip cancer), and mutations in the p53 tumor suppresser gene.
• Risk factors for different races are generally thought to be equal, but men (middle aged and old) are more likely to be afflicted than women.

Signs and Symptoms of Oropharyngeal cancer
Squamous cell carcinoma accounts for the vast majority of all malignant cases of oropharyngeal cancer and usually occurs in a number of high risk areas. These include

• The floor of the mouth.
• Ventro lateral tongue.
• The soft palate complex (including the soft palate proper, lingual aspect of retro molar trigone, and anterior tonsillar pillar).
• The lower lip.

Squamous cell carcinomas are sometimes preceded by mucosal changes known as pre–malignant lesions. Therefore, it is important that the clinician recognizes that lesions such as leukoplakia, erythroplakia, lichen planus, oral epithelial atrophy and sub mucous fibrosis, have the potential to become malignant.

Early Squamous Cell Carcinoma may present as

• White patch.
• Erythematous area.
• Fissure.
• Nodule.
• Ulcer, tending to have a rolled and inverted border with an indurated base and/or persisting more than two weeks.

More advanced lesions are marked by indurations, ulceration, and fixation and mobility of teeth. The extensive spread to local structures may produce symptoms such as tongue immobility, trismus, pathological fracture and disturbance of sensory or motor function. Ulceration of the lesion will produce infection and reactive hyperplasia of regional lymph nodes.

Investigations for Oropharyngeal cancer
As the clinician conducts a thorough patient history, and extra–oral and intra–oral examinations of a patient, some of the clinical appearances of oral cancer may be observed. To attain a definitive diagnosis of an oral condition, diagnostic tests, such as an oral biopsy, should be conducted or the patient should be referred to appropriate specialists.

Indications for biopsy

• When any lesion, not positively diagnosed by other methods, fails to heal spontaneously with conservative therapy( for example red, white, or pigmented lesions).
• Whenever symptoms are suggestive of neoplasia. All tumors suggestive of malignancy, as well as benign growths, should be examined histologically.
• Where there is any cystic lesion of the soft tissue or bone.
• Any medical or dental general practitioner is capable of removing suspect tissue and submitting it to a pathologist. However, biopsies of certain sites such as the floor of the mouth, soft palate, and external portions of the lips, can present esthetic and surgical considerations that are best evaluated by specialists such as oral and maxillofacial surgeons, otolaryngologists, or oral pathologists. Biopsies of the tongue, inner lip, and buccal and alveolar mucosa constitute less of a surgical problem and can be performed in a primary care office.

Several generalizations can be made when performing minor oral surgical procedures and biopsies

• Prophylactic antibiotics should be administered in patients with valvular heart disease and other conditions that predispose them to infective endocarditis, as well as patients with endoprosthesis (eg. prosthetic hip and knee replacements).
• The local anesthetic should contain a vasoconstrictor (eg. epinephrine) to minimize bleeding and retard the vascular absorption of the anesthetic.
• Topical lidocaine applied to the oral mucosa will reduce discomfort when the local anesthetic is injected.
• Post surgical hemostasis can be obtained by digital pressure with gauze, aluminum chloride, or silver nitrate, electrodessication is infrequently required.
• Commonly used surgical modalities include: Scalpel excision with chalazion clamp is most useful on mobile mucosa such as the lip, tongue, and buccal mucosa and in deep tissue sampling.
• Punch biopsy: Disposable punches in graduated sizes (2–6mm) are available. Normally do not require sutured closure and heal adequately in several weeks.

Treatment of Oral cancer
The treatment of oral cancer, depending upon the site and extent of the primary tumor and the status of lymph nodes, may include surgery alone, radiation therapy alone, or a combination of the two.