Etiology and epidemiology of oral cancer.

1. EPIDEMIOLOGY
OF ORAL
CANCER

2. INTRODUCTION
Major threat to public health in developing and developed sector.
Cancer is the second most common cause of death.

3. 4 characteristic features:
Clonality
Autonomy
Anaplasia
Metastasis

4. EPIDEMIOLOGY OF ORAL CANCER
Oral 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.

5. ICDS CLASSIFICATION
In 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

6. 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??

7. Age, gender and site distribution
Predominant 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.

8. Etiology of Oral Cancer
 Tobacco
 Alcohol
 Exposure to sun
 Diet and Nutrition
 Fungal infections
 Viral infections
 Trauma and dental irritation
 Genetic factors

9. TOBACCO
It 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.

10. RECIPE FOR DISASTER
Tobacco 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

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

12. Constituents of Tobacco
CONSTITUENTS 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

13. TOBACCO PREPARATIONS
SMOKED TOBACCO
Bidi
Chillum
Chutta
Cigarettes
Dhumti
Hookah
Hookli
SMOKELESS TOBACCO
Khaini
Mainpuri tobacco
Mawa
Mishri
Paan
Snuff
Zarda
Gutka
Gudaku

14. BIDI
0.2 to 0.3 gms of sun dried tobacco
flakes are hand rolled.
Nicotine 1.7 to 3.0 mgs
Tar 45to50mgs
CHILLUM
A 14 cms straight conical clay pipe
Coarsely 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

15. CHUTTA
Cured tobacco is wrapped in a dried
tobacco leaf.
It is also called as cigar
CIGARETTES
1 gm of tobacco cured in the sun or
artificial heat is covered with a paper
Nicotine 1-1.4mg
Tar 19-27mg

16. DHUMTI
Rolled leaf tobacco is used inside a leaf
of jack fruit tree
HOOKAH
Tobacco smoke is drawn through the
water in the base of hookah which cools
and filters the smoke
It is also called water pipe or hobble-
bubble

17. HOOKLI
Clay pipe of 7 to 10 cms long with a
mouth piece and a bowl
KHAINI
Powdered sundried tobacco, slaked
lime-paste mixture occasionally with
used with areca nut

18. MAINPURI TOBACCO
Tobacco, slaked lime, finely cut areca nut,
camphor, cloves
MAWA
Thin shavings of areca nut + tobacco +
slaked lime are wrapped in cellophane
paper and tied in a shape of a ball
It should be vigorously mixed before
consumption

19. MISHRI
The roasted tobacco is powdered +
catechu(a residual extract obtained by
soaking the heartwood of acacia
catechu
PAAN
Betel leaf+ areca nut+ tobacco +lime+
cinnamon or coconut or cloves or sugar
are wrapped in betel leaf

20. SNUFF
Finely powdered air cured and fire
cured tobacco leaves+ areca nut + lime
carried in a metal container
It is locally called MUKKU PODUMU
ZARDA
Tobacco leaf is boiled in water along
with lime and spices until evaporation.
The residual tobacco is dried and
coloured with dyes.

21. GUTKA
Crushed betel nut, tobacco, sweet or
savory flavorings
GUDAKHU
Paste of powdered tobacco, molasses,
and other ingredients primarily used to
clean the teeth.

22. ALCOHOL
It 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.

23. Exposure to Sun
Effect 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 manganese
shows protective effect against cancer.
Red chilli powder has emerged as a risk factor to cancer

24. 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).

25. 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)

26. 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.

27. Precancerouslesions Precancerouscondition
1. Leukoplakia
2. Erythroplakia
3. Leukodema
4. Smokers palate
5. Palatal erythema
1. Oral Sub mucous Fibrosis
2. Lichen planus

28. Precancerous lesions
Leukoplakia Erythroplakia
leukedema Palatal erythema
Smokers palate

29. Precancerous condition
Oral submucous fibrosis Lichen planus

30. Squamouscell 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

31. 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.

32. 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.

33. WHO Frameworkconvention 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

34. 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.

35. BLOOMBERG INTIATIVETO 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.

36. Prevention and control of oral cancer
Mainly focuses on modifying habits associated with the use of tobacco.
India- 4th largest consumer and 3rd largest producer of tobacco.
3 well-known approaches:
Educatio
nal
approac
h
Service
approa
ch
Regulat
ory or
legal
approac
h

37. 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.

38. SERVICE APPROACH
Services provided by the professionals.-
In order to be suitable for screening certain criteria have to be met
Disease 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 examination
Toludine Blue Vital Staining
Other techniques used are –
Biopsy Techniques.
Exfoliative Cytology.

39. Educational approach
Dentist
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

40. DANGER SIGNALS
Any 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.

41. 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)

42. Counseling those unwilling to quit (5R)

43. 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.

44. 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.