BETEL-QUID AND ARECA-NUT CHEWING - IARC Monographs

BETEL-QUID AND ARECA-NUT CHEWING 87
Table 35. Numbers of oral cancers and prevalence per 1000 population in a
study in Mainpuri district, India a
Habit
No tobacco Mainpuri tobacco Other kinds of tobacco
No. of
cases
Gupta et al. (1980) followed a random sample of 10 287 individuals in Kerala
(Ernakulam district) for a period of 10 years (1966–77) in house-to-house surveys, with
a follow-up rate of 87%. Chewing betel quid with tobacco was a common habit in that
area, and all 13 new cases of oral cancer were diagnosed among either chewers only or
chewers who also smoked. The person–years method was used for data analysis and
incidence rates were age-adjusted (Table 37).
Apparently healthy subjects aged 35 years or older in rural Kerala were included from
1995–98 in an intervention trial, in which 59 894 individuals formed the screened group
and 54 707 formed the non-screened group. Those in the screened group who chewed
betel quid with tobacco, smoked or drank alcohol were advised to stop their habit; 31 and
44% of subjects in the screened and non-screened groups, respectively, reported no
tobacco (chewing betel quid with tobacco or smoking) or alcohol habit. About 3 years
after the start of the study, 47 cases of oral cancer (incidence, 56.1/100 000 person–years)
were identified in the screened group and 16 (incidence, 20.3/100 00 person–years) in the
non-screened group (Sankaranarayanan et al., 2000).
(c) Case–control studies
Prevalence No. of
cases
Prevalence No. of
cases
No habit 27 0.18 59 4.51 32 0.80
Alcohol drinking 0 0 6 6.59 2 1.08
Smoking 54 0.57 78 8.12 47 1.76
Drinking and smoking 9 1.56 30 11.45 2 0.58
Total 90 0.36 173 6.60 83 1.15
a From Wahi (1968)
Prevalence
Case–control studies for oral (comprising gum, floor of the mouth, buccal mucosa
and palate; the tongue may also be included) and other cancers and their association with
chewing betel quid with or without tobacco are described in Table 38 and the dose–
response relationships found in these studies are summarized in Table 39. [Data for men
and women were combined and relative risks were calculated by the Working Group of
IARC Monographs Volume 37 from the data given in the papers published up to 1985,
unless provided by the authors]. The derived relative risk estimates for use of betel quid
ranged from 0.1 to 45.9 in different studies.
A case–control study was reported by Shanta and Krishnamurthi (1959), consisting of
206 cancers of the buccal mucosa and the floor of the mouth and 278 randomly selected