Tobacco and Public Health - TCSC Indonesia

MICHAEL J. THUN AND JANE HENLEY 29
Lung cancer mortality increased enormously in women smokers over the 26-year
period. Not shown in Fig. 2.1 is that the death rate from lung cancer remained essentially
constant over this interval among women who had never smoked (Garfinkel
1981; Thun et al. 1997). Consequently, the relative risk associated with current cigarette
smoking in women increased from approximately 2 in 1960–64 to nearly 11 in
1982–86. The protracted increase in lung cancer among women smokers contradicted
the hypothesis of the early 1950s, that women might be less susceptible than men to
the adverse effects of smoking, and refuted the theory proposed by R. A. Fisher that the
absence of increasing lung cancer among women smokers in the 1950s was evidence
that smoking did not cause lung cancer (Fisher 1958). Instead, it supported Doll’s prediction
(Doll et al. 1980), that as successive birth cohorts of women smoked more intensively
from earlier ages, their lung cancer risk would approach that of male smokers.
An analogous picture of the progression of the epidemic is apparent in the widening
gap in overall survival between cigarette smokers and lifelong non-smokers from the
first to the second half of the British Doctors Study. Figure 2.2 illustrates the probability
of survival to various ages beyond 40 years among male British doctors who never
smoked tobacco, or who currently smoked cigarettes during the first or second 20-year
interval of follow-up (Doll et al. 1994). During both time periods, the percentage surviving
was higher among men who had never smoked than among those who smoked
regularly. The percentage surviving to age 70 was 58 per cent among current cigarette
Lung cancer death rate per 100 000
400
350
300
250
200
150
100
50
0
CPS-I 1960–64
CPS-I 1965–68
CPS-I 1969–72
CPS-II 1982–86
45–49 50–54 55–59 60–64 65–69 70–74 75–79
Age (years)
Fig. 2.1 Age-specific lung cancer death rates among women who currently smoked cigarettes
when enrolled in CPS-I and CPS-II (from Garfinkel and Stellman 1988).