Definition of cancer: “Abnormal mass of tissue the growth of which exceeds and is uncoordinated with neighbouring tissue and growth persist in same exceesive manner even after the ceassation of the stimuli which evoked the change.” Cancer occurring in any part of oral cavity is termed as oral cancer.
Oral cancer is the sixth deadliest cancer in the world. While most cancer survival rates have increased over the past 40 years., the five year survival rate of oral cancer has remained below 50 %.
Risk Factors: Chemical irritants ( tobacco,alcohol , mouthwashes with high alcohol content ) Physical irritants ( Denture use, prolonged denture irritaion , irregular teeth or restoration, chronic cheek biting habits ) Nutritional factors ( defficiency of vitamin A and caretenoid supplementation)
Prolonged sun exposure Hormonal effects Viruses (HPV) Genetics Risk Factors:
Increased risk: Patient age 40 and older(95% of cases) 18-39 years of age combined with the following: Tobacco use Chronic alcohol consumption Oral HPV infection Highest risk: Patient age 65 and older with lifestyle risk factors Patients with history of other cancer
Signs and symptoms or oral cancer A sore in the mouth that doesn’t heal Persistent mouth pain. A lump or thickening in the cheek. A white or red patch on the gums, tongue, tonsil or lining of the mouth. A sore throst or feeling that soomething is caught in the throat that doesn’t go away. Difficulty in swallowing or chewing. Difficulty in moving the jaw or tongue.
Numbness of the tongue or elsewhere in the mouth. Jaw swelling that makes denture hurt or fit pooryly . Loosening of the teeth. Pain in the teeth or jaw. Voice change. A lump in the neck. Significant weight loss. Persistent bad breath.
1. Primary prevention
1. Primary prevention
Key Messages for primary prevention
2. Secondary prevention
Oral cancer screening: It is an examination performed by the dentist of the doctor to look for the signs of cancer or precancerous conditions in your mouth. The goal of oral cancer screening is to identify mouth cancer early, when there is a greater chance for a cure. It can be done by examination of mouth during a routine dental check up or by use of additional tests to aid in identifying areas of abnormal cells in the mouth.
Oral cancer screening:
Screening preparation
Points to remember when screening for oral cancer Tell your patient whar are you doing with each procedure and why?? Special attention should be focused on the lesions of lateral border of tongue and floor of mouth . Always note any changes in colour texture of all soft tissue or any swelling, if you detect an abnormality determine the history of the lesion if the abnormality has been of more than 2 weeks duration,take appropriate action to obtain a biopsy.
Follow up to ensure a definitive diagnosis of an abnormality. Teach your patient about signs and symptoms of oral cancer. If patient uses tobacco products provide appropriate counselling or refer patient for counselling . Remove all removable prosthesis before starting the examination.
Dianostic aids Standard screening aids (conventional intra and extra oral examination) Established screening adjuncts (oral cytology,oral brush cytology) Vital staining ( toluedine blue,methylene blue,lugol’s iodine)
Extra oral examination : General appraisal Skull Facial form Skin Eyes Neurological deficit Lymph nodes of head and neck TMJ Masticatory musscles
Intra oral Examination
Drawbacks of conventional examination: It cannot discrimate between the lesion that are progressive or malignant and those non progressive. It doesn’t identify all potentially premalignant lesions.
Oral Cytology It is the study of cells which exfoliate or abrade from body surface.When epithelium becomes seat of any pathology cells lose their cohesiveness and cells in deeper layers may shed along with superficial cells. Drawback: the sensitivity and specificity differs due to its subjectivity or due to poor technique in obtaining cells and smear preparation.
Brush Biopsy(Oral CDx ) It utilizes a stiff brush to colled the sample cells from the basal layer cells non invasively and assess the dysplasia by computer asssisted neural network.
Vital Stains: Toluedene blue: It is a topical dye,which gets concentrate in cells with abundant nucleic acid.It has high sensitivity for detecting carcinoma. Interpretation Dark blue colour :positive for lesions suspicious malignancy Light blue: positive for premalignant lesions proved otherwise by biopsy.
Advantages: Specify area for biopsy. Cheap and non invasive,disposable Has high sensitivity for carcinoma Disadvantages: Its sensitivity for identifying dysplasia is poor. The colour of the dye remains in the mouth for 4 to 6 hours. It may give false positive results(inflammatory and ulcerative conditions).
2. Methylene Blue It is a heterotropic aromatic chemical compound.At room temperature it is solid,odourless dark green powder which yields a blue colour when dissolve in water. Advantages: It is cheaper and less cyto toxic.
Disadvantage: the result is not confirmatory. Application: Early detection of suspected oral cancer Treat Alzhiemer disease Examine(RNA) or (DNA) under microscope.
3.Lugol’s iodine It consist of 10 parts of potassium iodide to 5 parts of iodine.Application of iodine results in brown or black colour staining in areas containing glycogen. In areas lacking glycogen iodine isn’t absorped and such areas remain colourless or turn yellow. Advantages: Used for non keratinized stratified squamous epithelium. It is simple,low costs. High sensitivity with low false negative Result are fast
Disadvantage: It is an irritant cause abdominal pain,heart burn and nausea. Allergic reaction to iodine. Less accurate when used in post menopausal women. Application: Used routinely for the patient with head and neck cancer. Heavy smokers and drinkers.
Velscope The velscope handpiece emits a safe blue light into the oral cavity causing tissue fluorescence from the surface of epithelium through to the basal membrane-where pre malignant changes typically start.
By utilizing special optical filters in the velscope hand piece the clinician is able to immediately view the different fluorescence signatures in the oral tissues to help differentiate between normal and abnormal cellular activity. Abnormal tissue typically appears as an irregular, dark area that stands out against the green fluorescence pattern of surrounding healthy tissue.
Advantages: It takes only 1-2 mins and is painless and non invasive,with no stains and rinses required. Improves the distinction between normal and abnormal tissues. Thorough visual and digital soft tissue examination. Useful benefit in the determination of surgical border and post surgical evaluation. It covers large surface area so small lesions can also be identified.
Disadvantage Heat from prolonged and close tissue examination may cause patient discomfort. Lack of methodologically sound clinical trails. Insufficient use of histologic and molecular mapping.