Epidemiologic study of 6000 villagers oforal precancerous lesions in Bilugyun:preliminary report

KHIN MAUNG LAY, KYAW SEIN, AUNG MYINT, SUNN K O K O AND J, J, PINDBORG 1

Institute of Dentat Medicine, Rangoon, Burma and Royat Dentat College and University Hospital (Rig.sho.spitalet), Copenhagen, Denntark

Lay, K, M,, Sein, K,, Myint, A,, Ko, S, K, & Pindborg, J, J,: Epidemiologic study of 6000villagers of oral precaneerous lesions in Bilugyun: preliminary report, Gommunity Dent,Oral Epidemiol, 1982: 10: 152-155,

Abstraet - A house-to-house survey of 11 villages selected by randoi'n sampling was earried out inBilugyun, Ghaung-zone township, Mon State of South Eastern Burma to study the prevalenee oforal precaneerous lesions and smoking and ehewing, A total of 6000 villagers who were above 15years at the time of this study were examined. The prevalenee of preleukoplakia was 0,3%,leukoplakia 1,7%, lichen planus 0,4%, leukokeratosis nieotina palati 2,3, erythroplakia 0,1%,submucous fibrosis 0,1 %, and cancer 0,03%, A correlation was done between habits and lesions.

Key words: candidiasis, oral; erythroplakia; leukokeratosis nieotina palati; leukoplakia, oral;lichen planus; preeaneer; smoking; submueous fibrosis; tobaeeo,

Khin Maung Lay, Institute of Dental Medicine, Rangoon, Burma, >;

Accepted for publieation 3 August 1981, I

The Union of the Socialist Republic of Burma is anext door neighbor of India, where oral habits suchas smoking and chewing habits are common andwhere the incidence of oral cancer is also thehighest in the world. This alarming condition inIndia thus is of concern in Burma and has motiv-ated us to carry out a survey of oral precancerouslesions in Burma, where similar oral habits arefound,

Burma lies in South East Asia between latitudes9,58' N and 28.31' N and longitudes 92' 10' E and101' 108 E. Burma is bordered by Bangladesh andIndia on the northwest, China on the northeast,and Laos and Thailand on the southeast. TheAndaman Sea and the Bay of Bengal lie to the southand southwest.

Burma has an area of 678033 km'̂ and apopulation of 32.57 million in 1978 with thepopulation growth rate of 2.2%. Children under 15years of age make up 40.4% of the population; 15-59-year-olds make up 53,5% and 60-year-olds andolder make up 6,1 %.

According to the new constitution, Burma isadministratively divided into seven states andseven divisions. The present survey was carried outin one of the states of Southeastern Burma, knownas the Mon State,

MATERIAL AND METHODSEXAMINATION PROGEDURES

The survey was earried out on the island of Bilugyun, which issituated just opposite the Moulmein, the capital of Mon Slate,between latitudes 16,5' and 16,2' N and longitudes 97,5' and97,8' E (Fig, 1), The climate of the region is Iropical,

Basic sampling population units were fixed around 6000inhabitants aged 15 years and above. The primary units in thesampling seheme were villages. All households of the selectedvillages were eonsidered seeondary units of the scheme. Allhousehold members aged 15 years and above were consideredbasic units of the sampling plan,

A house-to-house, instead of only the selected houses, surveywas ehosen as the survey method. Small villages assumed to bedeveloped were preferred for inelusion in the sampling frame,'Villages with more than 400 households were excluded fromthe sampling frame.

0301-5661/82/030152-04 S 02,50/0 '" 1982 Munksgaard, Copenhagen

Oral preeaneer in Burma 153

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Fig. 1. Map of Burma indicating wilh arrow the island wherethe study was made.

After using lhe constraints mentioned above, 25 villages outof 45 on the island remained eligible for selection. From the 25villages, 10 villages were randomly selected.

History forms were eompleted by trained clerks before theelinieal examination. The lesions were photographed in colorand eoded for location according to the WHO Oral Muco,salDiseases Manual (7),

Glinical examinations of lhe oral mucosa were done by fbtirtrained dentists, assisted by four reeord clerks, A pilot surveywas carried out in a similar locality on 1000 individuals of theKaren State, To achieve better comparability all the availablelesion eases previously examined individually by each team(one dentist and one reeord clerk) were again examinedsimultaneously by all teams in the presence of one of theauthors (J, J, P,) who had done similar studies in otherparlsofSoutheast Asia, Discussions were held in lhe field in order loachieve a standardized approach,

ORAL HABITS

Smoking habits - Gheroots and cigarettes are quite eommon inBurma, followed by pipes and cigars. Though il eannoi bestated for sure when the smoking habit started in Burma, many

believe that pipes were first introduced inlo Burma followed byeheroot smoking. Strangely enough, paintings of pipes may beseen among the wall paintings of the Pagan period (107-1325A, D,), but nothing is mentioned about pipes in the stoneinscriptions of that period. There are writings about thecheroot in the literature of the Kon-baung period (1752-1885A, D,),

Chewing Itabi/s - The belel leaf, known as "Kun-ywet" inBurmese, is the leaf of the betel vine with the botanical namepiper betel belonging to the family piperaceae, a native plant ofIndia, Sri Lanka, Burma and Malaysia, A betel quid contain-ing the betel nut-areea nut and other ingredients is collectivelyknown as "Kun-ya" or simply "Kun", Kun is frequentlymentioned in Burmese literature, showing how indispen,sable itwas and still is in almost all religious and social ceremonies.

The tradition goes back some hundred years, A marbleinscription from 1248 A, D, reads: "Ananta pinnya says. . .And hereby I offer two alms bowls, two betel nuts and leafweighing one-and-a-quarter tieals of brass to the guardians ofthe field. . .", Also from the literature and references made tothe betel box, it is evident that this artiele was an integral unitof the royal regalia. The social status or the official rank ofahost in the olden days could be easily ganged by the type andquality of the betel whieh he used.

RESULTSTable 1 gives information on the prevalences foundamong the 6000 villagers. Only one patient wasfound with candidiasis.

Table 2 gives the distribution according to ageand sex of the seven lesions and conditions men-tioned in Table 1. It is striking that men are aflectedby leukoplakia three times more often than women.The same is true for leukokeratosis nieotina palati.In contrast to these iindings, submucous fibrosis isseen four times more frequently among womenthan among men.

Table 3 gives information about the location ofsix of the lesions. It is interesting to note that bothpreleukoplakia and leukoplakia are more frequent-

I'able 1, Oral lesions by percentage

Lesion

PreleukoplakiaLeukoplakiaLichen planusf>eukokeratitis

nieotina palaliErythroplakiaSubniucous

librosisOral cancer

Number

1910123

1405

52

Percentage

0.31.70.4

2.30.1

0.10.03

154 LAY, SEIN, MYINT, K O AND PINDBORG

Table 2, Oral lesions by age and sex

Male Female Total Aver, age s,d.Age range

M F

PreleukoplakiaLeukoplakiaLiehen planusLeukokeratitis

nieotina palatiErythroplakiaSubmueous

fibrosisOral cancer

137711

1063

12

162412

342

40

1910123

1405

52

53,554,541,2

53,546,4

45,4075,50

19,114,915,7

15,020,3

15,807,8

25-8127-8225-59

19-8252-73

3070-81

18-7518-7515-75

19-7625-27

34-68

Table 3, Loeation of oral lesions

Loeation

CommissureRightLeft

Bueeal mucosaRightLeft '-

Labial mucosaRightLeft

Alveolarridge

Floor of themouth

TonguePalate 'Pterygomandibular

pliea & glossopalatalareh

Preleukoplakian

36

46

-1

1, - '

--

-

%

14,328,6

19,028,6

'-4,8

4,8

_--

-

Leukoplakian

1719

1724

-1

5

1127

-

%

16,518,5

16,523,3

-1,0

4,9

1,011,76.8

-

Liehenplanus

n %

--

11 31,413 37,1

--

1 2,9

--3 8,6

7 20,0

Erylhroplakian

--

36

--

-

--1

%

--

3060

--

-

--10

-

Submueousfibrosis

n

12

36

--

-

---

2

%

7,114,3

21,442,8

--

-

---

14,3

Oralcancer

n %

--

--

--

-

-1 204 80

- _

Table 4, Correlation of oral lesions with habits

Oral habit

ChewingAreea nut . 'Tobaeeo

SmokingPipeSmoking (any) • .

MixedPipe + areea nutSmoking + areea nut

Leukoplakia

524

'; 4589

2748

plan'

61_

•• 3 5

30

-52

Pereentage of persons with oral lesionsLeukokeratitis

Lichen nieotina Erythro- Submueouspalati plakia fibrosis

OralCaneer

72

m

80% 50%-

40%60%

40%40%

40%

20%80%,

• ' -

50%50%

-_

Oral preeaneer in Burma 155

ly found in the left than in the right side of thecommissures and buecal mucosa. Special attentionshould also be paid to the fact that four of the fiveoral cancers were located to the palate.

In Table 4 an attempt has been made to correlatethe lesions with chewing and smoking habits. Ofthose having leukoplakias, 52% chewed areea nutand only 4% chewed tobacco with areea nut. In thesame individuals, 45% smoked a pipe and 89% hadother smoking habits. Concerning mixed habits,27% of the leukoplakia patients smoked a pipe andchewed areea nut and 48% had other smokinghabits and chewed areea. Thus, it is apparent thatpatients with leukoplakias often have several smok-ing and chewing habits.

presetit survey. The prevalence of subtnucousfibrosis in our study is lower than in Gujarat (0.2%)and Kerala (0.4%) but is higher than in Andhra(0.04%). It is first time that submucous fibrosis hasbeen reported from Burma.

The reason for differences in prevalence ratesbetween Burma and India may be due to differ-enees in methods of blending tobacco and dif-ferences in mixtures for Burmese cheroot making.Burmese cheroots contain small pieces of porouswood chips in the mixture, which reduces theamount of tobacco.

Acknowledgment - This work was supported by WHO and theMinistry of Health, Burma,

DISCUSSIONWhen compared with reports from other studies,the prevalence of preleukoplakia in the presentstudy is lower than in Gujarat, Kerala and Andhrain India (4) with 4.1 %, 2.4% and 2.9%, respeetively.

Leukoplakia had a similar prevalence as in theIndian study. As for lichen planus, the prevalence isslightly higher than in Gujarat (0.1 %) and Andhra(0.3%), but lower than in Kerala (1.0%). Leuko-keratosis nieotina palati shows a much higherprevalence when compared with the figures fromGujarat and Kerala (0.2 and 0.3 %), but not as highas Andhra (9.5%) where reverse smoking is aprevalent habit. This habit was not found in the

REFERENCES1, Butma: Infbrmation and Broadcasting Department, Ran-

goon, Ministry of Infbnnalion, Printing and PublishingCorporation, Bmnia 1977,

2, Country Proftle, Burma; DGHS, Burma 1979; February,3, Eiving conditions in Burma. Regional Offiee for South-east

Asia of the World Health Organization 1973; May,4, Miiii'i'A, F, S,, PiNi)i!()R(;, J, J, lit H,'\MNKR, J, E,, III: Oral

cancer and precancerous conditions in India. Munksgaard,Copenhagen 1971,

5, NwE, M, K,: Sein-mya-nyo-ywet-tha-nat-phet (Burmese cherootleaf). (Burmese), Burma Translation Soeiety 1976,

6, SiciN, K, B,: The Guardian Magazine 1977: Dee,: 17-18,7, World Health Organization: Guide lo epidemiology and

diagnosis of oral mucosal diseases and conditions. CommunityDent. Otal Epidemiol. 1980: <9,' 1-26. ,