According to GLOBOCAN 2008, Oral Cancer ranks 11th among all cancers occurring around the world. Approximately two-thirds of patients in the developing countries of South and Southeast Asia, Eastern Europe and Latin America are affected by oral cancer. In India, oral cancer ranks among top three cancers showing highest incidences (age-standardized rate of 9.8 per 10000) and accounting for about 30% of all new cases annually. The overall 5-year survival rate for all stages of oral cancer is 60% with localised tumour showing better rates than one with regional or distant metastasis (spread).
- Smoking Tobacco: Cigarette, Bidi, Cigars, Chutta, different smoking pipes such as chillum, etc.
- Smokeless Tobacco: Betel quid, Paan, Supari, Khaini, Mishri, Zarda, Mawa etc.
Smoking increases the chance of developing oral cancer by 6 times, hookah and pipe by 16 times and bidi smoking by 36 times as compared to non- smokers. Similarly, chewing betel leaves, tobacco and lime increases the risk by six fold as compared to smokers and ten fold when its combination of both.
- Viruses such as Human Papilloma Virus (16 & 18), Epstein Barr Viruses, Herpes Simplex Viruses, Retroviruses.
Recent studies have shown and increase in number of HPV causing oral cancers. This usually seen in healthy non smokers segment of population in 25-50 years of age. Having multiple sex partners or engaging in oral sex with HPV infected partners is one of the reasons for contracting cancer. Weakened immune systems due to HIV/AIDS or Immune system suppressing drugs after organ transplants can also increase the risk.
- Diet and Deficiency States
- Sunlight or UV radiation effects
- Potentially Malignant Diseases such as leukoplakia. lichen planus, erythroplakia, oral submucous fibrosis etc
- Poor oral hygiene, faulty restorations, sharp teeth, ill fitting dentures
- Syphilis, Chronic Candidiasis
- Prior history of cancer
- Not established causes
- In Indian population oral cancer occurs 50 years and above, however, due to changes in personal habits and lifestyle it is seen occurring in younger population
- Males more frequently affected than females but the ratio is showing slow decline with increase in number of cases in females.
- Site at which oral cancer occurs has strong association placement of noxious irritants. Most commonly involved are lip, buccal mucosa, vestibule, alveolar ridge, hard palate, soft palate, tongue and floor of the mouth. The most common oropharyngeal site of involvement in Indian population is buccal mucosa followed by tongue.
- Classic features of oral malignancy include ulceration, nodularity, induration and fixation and cancer must be suspected especially when there is a single oral lesion persisting for more than 3 weeks.
WARNING SIGNS OF ORAL CANCER (as given by Crispian Scully)
- Red lesion (erythroplasia)
- Mixed red/white lesion, irregular white lesion, lump
- Ulcer with fissuring or raised exophytic margins
- Pain or numbness
- Abnormal blood vessels supplying a lump
- Loose tooth
- Extraction socket not healing
- Induration beneath a lesion, i.e., a firm infiltration beneath the mucosa
- Fixation of lesion to deeper tissues or to overlying skin or mucosa
- Lymph node enlargement
- Weight loss
- Key for prevention of oral cancer is early detection and treatment.
- Early diagnosis of potentially malignant lesions can reduce the chance of its transformation into malignancy.
- Thorough history (present, past medical/dental, habits, occupation, family) followed by physical examination is a must.
- Biopsy is a must in cases of oral cancer. Histopathological diagnosis is the gold standard however many other histotechniques can also be applied.
- DNA ploidy
- Serum and salivary biomarkers
- Optical systems
- Radiological imaging
- Primary prevention
- Surgery with or without neck dissection
- Dental rehabilitation