EPIDEMIOLOGY OF ORAL CANCER

INTRODUCTIONMajor threat to public health in developing and developed sector.

Cancer is the second most common cause of death.

4 characteristic features:ClonalityAutonomyAnaplasiaMetastasis

EPIDEMIOLOGY OF ORAL CANCEROral Cancer is one of the ten leading cancer in the world.

In India it is a common cancer & is an important public health

problem (third commonest cancer).

Tongue is the most common site ( lateral borders).

90-95% of oral cancer are of the squamous cell ca type.

ICDS CLASSIFICATIONIn the ICDS (WHO – 9th version) classification oral cancer is under

140-145.

Includes- Squamous cell Carcinoma of lip(ICD140)Tongue (ICD 141)Gum (ICD143)Floor of mouth (ICD144)

ICD refers to the WHO international classification of diseases

About 2.5 lakh new cases occur every year in India, Pakistan, Bangladesh etc.

Study done in Mumbai, Pune, Chennai and Bangalore: Higher in males except in Bangalore.

Indian Oral Cancer – Buccal mucosa(65%), lower alveolus(30%) and retro molar trigone(5%) : as these constitute more than 60% of all cancers.

WHAT DOES THE NUMBERS SAY??

Age, gender and site distributionPredominant in older age group.5th & 6th decade of life.In developing countries as compared to industrialized countries it is 2.5 times more in males & 4 times in females .

Cancer Registries in India

Hospital based registry.

Population based- definite population.

Special purpose registry for epidemiological study in a radiation exposed area.

Etiology of Oral Cancer Tobacco

Alcohol

Exposure to sun

Diet and Nutrition

Fungal infections

Viral infections

Trauma and dental irritation

Genetic factors

TOBACCOIt is estimated that 47 % of Indians aged 15 years or more use tobacco in one form or other. High incidence rates in India is associated with addition of betel quid chewing where addition of tobacco to quid is a critical factor.

RECIPE FOR DISASTERTobacco leaves

curing (fire curing, sun curing) for partial drying

further drying

fermentation/sweetening for months upto 2 years. During this time moisture loss reduces weight of tobacco

TOBACCODerived from Nicotiana tabacum and Nicotiana rusticum.CONSTITUENTS: Nicotine Tar Carbon monoxide Nitrogen oxide Hydrogen cyanide and other ciliatoxics Metals Radioactive compounds

Constituents of TobaccoCONSTITUENTS ADVERSE EFFECTS

Polycyclic aromatic hydrocarbon Carcinogenesis

Nicotine Carcinogenic

Phenol Ganglionic stimulation and depression & tumour promotion

Benzopyrene Tumour promotion & irritation

CO Impaired O2 transport

Formaldehyde and oxides of N2 Toxicity to cilia and irritation

Nitrosamine Carcinogenic

TOBACCO PREPARATIONS

SMOKED TOBACCO

Bidi Chillum Chutta Cigarettes Dhumti Hookah Hookli

SMOKELESS TOBACCO

Khaini Mainpuri tobacco Mawa Mishri Paan Snuff Zarda Gutka Gudaku

BIDI0.2 to 0.3 gms of sun dried tobacco flakes are hand rolled.Nicotine 1.7 to 3.0 mgsTar 45to50mgs

CHILLUMA 14 cms straight conical clay pipeCoarsely cut tobacco pieces and a glowing charcoal is kept on top.It is held vertically and to prevent tobacco from entering mouth a pebble stone is introduced

CHUTTACured tobacco is wrapped in a dried tobacco leaf.It is also called as cigar

CIGARETTES1 gm of tobacco cured in the sun or artificial heat is covered with a paper

Nicotine 1-1.4mgTar 19-27mg

DHUMTIRolled leaf tobacco is used inside a leaf of jack fruit tree

HOOKAHTobacco smoke is drawn through the water in the base of hookah which cools and filters the smokeIt is also called water pipe or hobble-bubble

HOOKLIClay pipe of 7 to 10 cms long with a mouth piece and a bowl

KHAINIPowdered sundried tobacco, slaked lime-paste mixture occasionally with used with areca nut

MAINPURI TOBACCOTobacco, slaked lime, finely cut areca nut, camphor, cloves

MAWAThin shavings of areca nut + tobacco + slaked lime are wrapped in cellophane paper and tied in a shape of a ballIt should be vigorously mixed before consumption

MISHRIThe roasted tobacco is powdered + catechu(a residual extract obtained by soaking the heartwood of acacia catechu

PAANBetel leaf+ areca nut+ tobacco +lime+ cinnamon or coconut or cloves or sugar are wrapped in betel leaf

SNUFFFinely powdered air cured and fire cured tobacco leaves+ areca nut + lime carried in a metal containerIt is locally called MUKKU PODUMU

ZARDATobacco leaf is boiled in water along with lime and spices until evaporation. The residual tobacco is dried and coloured with dyes.

GUTKACrushed betel nut, tobacco, sweet or savory flavorings

GUDAKHUPaste of powdered tobacco, molasses, and other ingredients primarily used to clean the teeth.

ALCOHOLIt is an independent risk factor.

Synergistic effect of tobacco & alcohol .

Accounts for 75% of all oral & pharyngeal cancer .

Heavy drinkers who smoked over 20 cigarettes a day were observed to have 24 times

more risk of oral cancer.

Exposure to SunEffect of Solar Radiation – Sunlight- Chronic exposure to sunlight – cancer

of the lip.

Diet and Nutrition-Vitamin A, C, E & Antioxidant[β-carotene] , copper, zinc and manganeseshows protective effect against cancer.

Red chilli powder has emerged as a risk factor to cancer

Fungal Infections Dysplastic lesions [leukoplakia] with candidial infection have greater risk of malignancy.

Viruses Human herpes virus1(HHV1),Herpes simplex virus1(HSV1),Human immunodeficiency virus have been associated with squamous cell carcinoma(SCC).

Trauma and dental irritation Continuous irritation from jagged teeth and dentures poor oral hygiene are risk factors for oral cancer .

Genetic factors-Alterations in in many genes have been implicated in development and progression oral cancer. Eg:3p (FHIT), 9P

(CDKN2A)

Definition….

Precancerous lesion-Is defined as morphologically altered tissue in which cancer is more likely to develop than its apparently normal counter part.

Precancerous condition-Its is a generalized state associated with a significantly increased risk of cancer.

Precancerous lesions Precancerous condition

1. Leukoplakia

2. Erythroplakia

3. Leukodema

4. Smokers palate

5. Palatal erythema

1. Oral Sub mucous Fibrosis

2. Lichen planus

Precancerous lesions

Leukoplakia

Erythroplakia

leukedema Palatal erythema

Smokers palate

Precancerous condition

Oral submucous fibrosis Lichen planus

Squamous cell carcinoma (Epidermoid carcinoma)

Most malignant neoplasm in the oral cavity Can occur as:• Carcinoma of lip• Carcinoma of tongue• Carcinoma of floor of mouth• Carcinoma of buccal mucosa• Carcinoma of gingiva• Carcinoma of palate• Carcinoma of maxillary sinus

GLOBAL INITIATIVES IN PREVENTION AND CONTROL OF ORAL CANCER

THE CRETE DECLARATION ON ORAL CANCER PREVENTION 2005.

WHO FRAMEWORK CONVENTION ON TOBACCO CONTROL.

BLOOMBERG INITIATIVE TO REDUCE TOBACCO CONTROL.

CRETE DECLARATION

Provision of systemic epidemiological information on prevalence of oral cancer and cancer

risk specially in developing countries. Promotion of research (biological, behavioral and

psychosocial factors of oral cancer).

Integrating oral cancer information into national health surveillance system.

Dissemination of information.

Active involvement of oral health professionals.

Training of primary health care worker in screening.

Access to health facilities and provision of system for early detection and intervention.

WHO Framework convention on tobacco control

WHO FCTC treaty opened – 16th to 22 June 2003.

168 signatories.

Most widely embraced treaties in UN history.

Member states – strive in good faith to ratify, accept or approve it and

show political commitment not to undermine the objective set out in it.

Into force – 27 Feb 2005

Spread..

Cross border effect, trade liberalization and direct foreign investment.

Global marketing, promotion and sponsorship and international

movement of contraband and counterfeit cigarettes.

Assert importance of –

Demand reduction strategies.

Supply reduction provisions.

BLOOMBERG INTIATIVE TO REDUCE TOBACCO USE

This initiative funded by Bloomberg philanthropies, is 2 year contribution of US$125 million by Michael R

Bloomberg for global tobacco control.

In 15 developing countries (Bangladesh, Brazil, China, Egypt, India, Indonesia, Pakistan, Poland, Thailand).

5 key partner organizations-

Campaign for tobacco free kids.

Centre for disease control and prevention foundation.

John Hopkins Bloomberg School of Public Health Education/training.

WHO/TFI.

World Lung Foundation.

Prevention and control of oral cancerMainly focuses on modifying habits associated with the use of tobacco.

India- 4th largest consumer and 3rd largest producer of tobacco.

3 well-known approaches:

Educational

approach

Service

approach

Regulatory approach In India, Cigarette act 1975 – print warnings on cigarette packets.

National Cancer Control Programme, 1985 – health warning displays & banning of advertisements on tobacco products.

In countries like Italy, Norway, Portugal etc – ban on advertising tobacco products.

Regulatory/legistlative measures

Ban tobacco and alcohol use.

Ensure adequate legislation .

Ensure warnings on products sold .

Increase cost.

Avoid glorification of products through advertisements.

SERVICE APPROACHServices provided by the professionals.-In order to be suitable for screening certain criteria have to be metDisease is serious yet treatable in early stages.Facilities for diagnosis and treatment exists. Natural history of disease is known. Screening tool is inexpensive and safe.For early detection – Self examinationToludine Blue Vital Staining Other techniques used are – Biopsy Techniques.Exfoliative Cytology.

Educational approachDentist

See harmful effects

Counsel child and youth patients

Spend more time with patients

Treat women of childbearing age

Build patient’s interest in quitting

Speak with authority in community

DANGER SIGNALSAny persistent scaly white patch

Any lesion which increase in size

Non healing ulcer

Non healing extraction socket

Facial asymmetry

Oral numbness or pain during jaw movements.

Guide to Counseling for tobacco cessation (5A’s)Ask – use of tobacco

Advise – non users to never use and users to quit

Assess- the patient readiness to quit

Assist- with quitting

Arrange- for follow ups

Use of Pharmacotherapy

Nicotine replacement therapy

Antidepressants (Selegeline, Clonidine)

Counseling those unwilling to quit (5R)

CONCLUSION No Tobacco Day” is being observed on the 31st May.

The suffering, disfigurement and death due to oral cancer is easily avoidable since

the factors associated with the disease have been identified.

Another important aspect is its easy accessibility for diagnosis. This feature along

with the finding that oral cancer is generally preceded by precancerous lesions

provide an excellent opportunity for early detection and control.

For further reading, Refer..

1. Hiremath S. S. Textbook of Preventive and Community Dentistry. (2nd

edition). New Delhi: Elsevier; 2011

2. Soben Peter. Essentials of Preventive and Community Dentistry. 4th ed.