Tobacco and Public Health - TCSC Indonesia

416
TOBACCO USE AND RISK OF ORAL CANCER
smokers of blond tobacco. Smoking cessation resulted in a decrease in risk after
5 years’ abstention.
Merletti et al. (1989) from Italy reported a four- to sixfold increased risk among
subjects with medium or high tobacco consumption in both males and females.
A trend in increasing risk with duration of smoking was observed in men, but not in
women. As reported by Franceschi et al. (1990), younger age at start of smoking was
found to be associated with a higher risk in this study, and smoking cessation is associated
with a sharp risk reduction. Subjects smoking black cigarettes had a higher risk,
while use of filter cigarettes showed no clear risk difference.
Marshall et al. (1992) reported the results from a case–control study in western
New York, and they found that, while the risk associated with cigarette smoking did
not increase in strict dose–response fashion, it was sizably and significantly elevated
from those who had 21–30 pack-years of smoking (OR = 2.7, 95% CI 1.2–6.0) to those
who had more than 70 pack-years of smoking (OR = 5.7, 95% CI 2.7–12.1).
Using data from a multicenter population-based case–control study of oral cancer
risk factors in the US (1065 cases and 1182 controls), Day et al. (1993) examined the
Black-White differences in the risk of oral cancer associated with tobacco smoking.
The study found that the patterns of risk among smokers were generally similar among
blacks and whites. After controlling for alcohol consumption, the risk was almost
doubled for those who smoked 20–39 cigarettes per day, and tripled for those who
smoked 40 or more cigarettes per day. The alcohol-adjusted OR for current smokers
was higher among Whites (OR = 3.6, 95% CI 2.6–4.8) than among Blacks (OR = 2.3,
95% CI 1.1–4.7), but this difference was not statistically significant. The risk declined
sharply with cessation of smoking for both racial groups, with little elevation in risk
even for those who had quit smoking 1–9 years earlier.
Tobacco smoking was also found to be significantly associated with the risk of
second cancers of the oral cavity and pharynx in a nested case–control study by
Day et al. (1994). The effects of smoking was found to be more pronounced than those
of alcohol in this study. Current smokers relative to never and former smokers had an
OR of 4.3 (95% CI 1.6–12). The alcohol-adjusted ORs for smoking rose with duration
and intensity of smoking. Risk, however, was significantly reduced 5 years after smoking
cessation.
Bundgaard et al. (1995) in Denmark also reported an increased risk of oral cancer
associated with increasing lifetime kilogram cigarette smoking (P trend < 0.001) and
with current daily amount of smoking (P trend < 0.001). For those who had a lifetime
consumption of cigarettes greater than 235 kg, the OR was 6.3 (95% CI 3.1–12.9). The
OR was 5.8 (95% CI 3.1–10.9) for those with current consumption of more than
20 cigarettes per day.
A dose–response relationship was observed for daily grams of cigarette smoking in a
case–control study by Andre et al. (1995) in France. The study found that those who
smoked more than one packet of cigarettes a day had a risk that was 13 times higher