BETEL-QUID AND ARECA-NUT CHEWING - IARC Monographs

BETEL-QUID AND ARECA-NUT CHEWING 89
Table 37. Chewing and smoking habits and oral cancer in two cohort
studies, India
Habit
Ahmedabad a Ernakulam b
Number
re-examined c
New oral
cancers
Incidence
per 100 000
Person–
years
New oral
cancers
Chewing 3 266 1 31 23 416 9 23
Chewing and
smoking
16 881 6 36 8 476 4 32
Smoking 15 378 6 39 20 222 0 0
None 7 065 0 0 30 962 0 0
Age-adjusted
incidence per
100 000
a Industrial workers aged 35 years and over; data from Bhargava et al. (1975)
b House-to-house survey of individuals aged 15 years and over; data from Gupta et al. (1980)
c Approximately 2 years after the first examination
Chandra (1962) reported a study of 450 cases of cancer of the cheek (287 men, 163
women) and 500 hospital visitor controls (410 men, 90 women) conducted in 1955–59.
The proportion of betel-quid chewers was 5.6% and that of chewers of betel quid with
tobacco was 23.3% among male cases. Corresponding proportions among male controls
were 13.4 and 10.7%, respectively. The proportions among female cases were 18.4 and
43.5% and those among female controls were 16.7 and 18.9%, respectively.
In another case–control study, Shanta and Krishnamurthi (1963) reported on 882
cancer cases (628 men, 254 women) and 400 (300 men, 100 women) controls. Cancer sites
included lip (12 men, seven women), buccal mucosa (293 men, 152 women), anterior
tongue (69 men, 18 women), posterior tongue (48 men, four women), pharynx (130 men,
25 women), hypopharynx (18 men, 12 women) and oesophagus (57 men, 36 women). For
cancer of these different sites, the proportion of male cases who chewed betel quid without
tobacco ranged from 8.4 to 38.5% and that among male controls was 49.1%; the proportion
of female cases who chewed betel quid without tobacco ranged from 12.4 to 55.5% and
that among female controls was 55.5%. [The authors pointed out that most chewers of
betel quid without tobacco were occasional chewers and the percentage was high because
it was very hard to find Indians who had not chewed betel quid without tobacco at one time
or another. They opined that betel-quid and areca-nut chewing was of no statistical significance
in etiology and is only a reflection of habit in the general population.]
Hirayama (1966) reported a case–control study of oral and oropharyngeal cancers conducted
in India and Sri Lanka. The study included 545 cases of cancer of the buccal mucosa
(369 men, 176 women), 143 cases of cancer of the anterior tongue (117 men, 26 women),
37 cases of cancer of the palate (28 men, nine women), 102 cases of cancer of the oropharynx
(81 men, 21 women) and 440 controls (277 men, 163 women). The proportion of
men who chewed areca nut (reported as betel nut) was 0.8% for cancer of the buccal