Oral cancer overview
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Oral cancer overview On the Web |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Simrat Sarai, M.D. [2]
Overview
Oral cancer or mouth cancer is a type of head and neck cancer and is any cancerous tissue growth located in the oral cavity. Oral cancer is a malignant growth that affects any part of the oral cavity, including the lips, gums, tongue, inside lining of the cheeks, roof of the mouth and floor of the mouth. It may arise as a primary lesion originating in any of the tissues in the mouth, by metastasis from a distant site of origin, or by extension from a neighboring anatomic structure, such as the nasal cavity. Alternatively, the oral cancers may originate in any of the tissues of the mouth, and may be of varied histologic types.[1]
Classification
Oral cancer can be classified into three types based on the potential to spread to other parts of the body such as malignant tumors, precancerous conditions, and benign tumors.
Pathophysiology
Genes involved in the pathogenesis of oral cancer include tumor suppressor genes (TSGs), particularly in chromosomes 3, 9, 11, and 17.
Causes
Common causes of oral cancer include premalignant lesion, tobacco, alcohol, human papillomavirus, and hematopoietic stem cell transplantation.
Differentiating Oral cancer from other diseases
Oral cancer must be differentiated from actinic keratosis, dermatologic manifestations of oral leukoplakia, erythroplasia, lichen planus and mucosal candidiasis.
Epidemiology and Demographics
The prevalence of oral cancer is estimated to be 91,200 cases annually. Each year the incidence of oral cancer is estimated to be 37,000 cases per 100,000 individuals in United States. Oral cancers are the sixth most common cancers in the world.
Risk factors
The most potent risk factor in the development of oral cancer is alcohol intake and tobacco use. The other risk factors include male gender, age over 55 year, ultraviolet light, Fanconi anemia, dyskeratosis congenita, HPV infection, graft-versus-host disease(GVHD), mouthwash and irritation from dentures.
Screening
The goal of oral cancer screening is to detect mouth cancer or precancerous lesions that may lead to mouth cancer but no studies have proved that oral cancer screening saves lives. People with a high risk of oral cancer may be more likely to benefit from oral cancer screening.
Natural History, Complications and Prognosis
Depending on the extent of the tumor at the time of diagnosis, the prognosis may vary. The 5-year survival rate for oral cancer diagnosed early is 75% compared to 20% for oral cancer diagnosed late.
Staging
According to the TNM staging system by the American Joint Committee on cancer, there are four stages of oral cancer based on the tumor size, lymph nodes involved, and metastasis.
History and Symptoms
Symptoms of oral cancer include a white or red patch in the mouth, mouth pain, bleeding in the mouth, numbness in the tongue, difficulty chewing or swallowing, ear pain, difficulty moving the jaw or tongue, loose tooth, persistent bad breath and, weight loss.
Physical Examination
Common physical examination findings of oral cancer include a lump or thickening in the oral soft tissues, soreness, difficulty chewing or swallowing, ear pain, difficulty moving the jaw or tongue, hoarseness, numbness of the tongue or swelling of the jaw that causes dentures to fit poorly.
Laboratory Findings
Some patients with oral cancer may have elevated liver function tests, abnormal urea and electrolyte measurements, elevated calcium levels, elevated serum ferritin, alpha-antitrypsin, and alpha-antiglycoprotein levels may be increased in high-stage cancer of oral cavity while those at any stage of disease have increased haptoglobin levels.Prealbumin levels are decreased slightly in persons at any stage.
CT
Head and Neck CT scan may be diagnostic of oral cancer.
MRI
Oral MRI scan may be diagnostic of oral cancer.
Other Imaging Findings
A PET scan may be diagnostic of spread of oral cancer.
Other Diagnostic Studies
Biopsy of the tumor tissue is diagnostic of oral cancer. Other diagnostic studies for oral cancer include endoscopy, indirect pharyngoscopy, laryngoscopy, exfoliative cytology, barium swallow, chest x-ray and bone scan.
Medical Therapy
The predominant therapy for oral cancer is surgical resection, radiation therapy or a combination of both. Adjunctive chemotherapy/radiation/chemoradiation may be required.
Surgery
Surgery is the mainstay of treatment for oral cancer.
Primary Prevention
Effective measures for the primary prevention of oral cancer include tobacco cessation, alcohol cessation, eating variety of fruits and vegetables, and avoiding excessive sun exposure.