Tobacco and Public Health - TCSC Indonesia

GRAHAM G. GILES AND PETER BOYLE 489
reported: useable replies were obtained from relatives of 93 men and 16 women. Of the
women, 13 were non-smokers (Schairer and Schoniger 1943). The authors attempted
to collect control information by interviewing 700 men in Jena between the ages of
53 and 54, the average age of the lung cancer patients at death (53.9 years). It was a
study performed in Germany towards the end of the Second World War and only
270 men from Jena responded to the questionnaire. The authors showed great insight
in concluding that wartime conditions (particularly the rationing system) may have
favoured results from non-smokers. They reported a statistically significant difference
in non-smokers and heavy smokers among lung cancer patients on the one hand and
normal patients on the other. Realizing the possible errors in their material they concluded
that there was a considerable probability that lung cancer was far more frequent
among heavy smokers and far less frequent among non-smokers than expected. Their
data is such that an approximate relative risk can be calculated and the risk relative
to non-smokers was 1.9 among light smokers; 9.1 among moderate smokers, and
11.3 among heavy/excessive smokers. Again there appears to be a moderate dose–
response relationship. A further study from the Netherlands (Wassink 1948) identified
very similar associations between smoking and lung cancer.
Over the first few decades of the twentieth century, reports began not only to admit
that the incidence of lung cancer was increasing (Clemmeson and Buck 1947) but also
to associate the increase with smoking rather than better diagnosis or increased
longevity of the population (Anon 1942). These findings were largely ignored until
1950, when five case–control studies of the topic were published (Doll and Hill 1950;
Levin et al. 1950; Mills and Porter 1950; Schrek et al. 1950; Wynder and Graham 1950)
that included altogether over 2000 cases, the two largest studies having over 600 cases
each and an equivalent numbers of controls (Doll and Hill 1950; Wynder and Graham
1950). Their conclusions were virtually identical—that smoking, particularly cigarette
smoking, was an important factor in the production of lung cancer. The evidence from
these studies, however, failed to gain wide acceptance. Instead it attracted opposition,
not only from the tobacco industry but also from some other scientists because,
although an association between smoking and lung cancer had been demonstrated,
few were willing to accept it as evidence of a causal relationship, as at this time the
case–control design was considered by many to have too many defects for it to produce
reliable, unbiased findings (Sadowsky et al. 1953; Hammond 1954).
The methodological problems of case–control studies were to be overcome by using
another epidemiological design, and shortly after the publication of the first case–
control studies, the results of two prospective cohort studies came to hand (Doll and
Hill 1954; Hammond and Horn 1958). These two cohort studies essentially confirmed
the strong associations that had been shown between cigarette smoking and lung cancer
by the case–control studies, and gave additional information; e.g. with respect to the
dose–response relationship between the amount smoked and the risk of lung cancer
and the decrease in risk in those who were able to stop the habit.