Tobacco and Public Health - TCSC Indonesia

steady increase in lung cancer occurrence among smokers, although this was based on
only 36 lung cancers. The age standardized rate increased from 0.00 per 1000 among
the 3093 non-smokers, to 1.14 per 1000 among the 5203 men recorded as smoking 25 g
or more of tobacco daily. A similar, but less steep, rise was seen in mortality from coronary
thrombosis (from a rate of 3.89 in non-smokers, to 5.15 in the heaviest smokers).
In the Hammond Horn study, men with a history of regular cigarette smoking had a
substantially higher death rate from all causes (based on 4854 deaths), from coronary
heart disease (1328 deaths), and from lung cancer (167 deaths) than men who had
never smoked regularly.
A second report from the British Doctors Study was published in 1956, based on 84
confirmed cases of lung cancer. This, too, demonstrated a steady increase in the annual
death rate from lung cancer with increasing amount smoked (Doll and Hill 1956). The
annual death rate in men who smoked at least 25 g (approximately 25 cigarettes) per
day was 1.66 per 1000, over 20 times the death rate of the non-smokers (0.07 per
1000). Greater cigarette consumption was also associated with higher death rates from
chronic bronchitis, peptic ulcer, and pulmonary tuberculosis, although the trend was
statistically significant only for chronic bronchitis.
Of interest is that the principal investigators of the earliest cohort studies did not initially
expect that cigarette smoking would prove to be the cause of the increasing lung
cancer incidence in the United Kingdom and United States. When Doll first began
work on the British case-control study in 1948, he suspected that ‘motor cars and the
tarring of roads’ were a more likely explanation than cigarette smoking (Doll 1998a).
However, both Doll and Hill were impressed by the results of the case-control study,
and in their 1950 publication concluded that ‘smoking is a factor, and an important
factor, in the production of carcinoma of the lung’ (Doll and Hill 1950). Hammond
and Horn, both of whom were smokers at the time, remained skeptical of the earlier
case-control studies that associated lung cancer with cigarette smoking. When they
began the first ACS cohort study, they considered it equally plausible that automotive
exhaust, dust from tarred roads, and/or air pollution from coal and oil furnaces might
be partly or wholly responsible (Hammond and Horn 1952; Hammond 1953).
However, the results of their Nine State Study (Hammond 1954; Hammond and Horn
1958a, b) persuaded Hammond and Horn to stop smoking and to focus ACS attention
on tobacco use as an important cause of cancer and other diseases.
Growing scientific consensus
MICHAEL J. THUN AND JANE HENLEY 23
Sufficient scientific evidence had accumulated by the late 1950s that at least six scientific
consensus groups concluded that cigarette smokers had higher lung cancer death
rates than non-smokers. These expert reviews were convened by health ministries in
the United Kingdom (Medical Research Council 1957), United States (Burney 1959),
Canada (National Cancer Institute of Canada 1958), Sweden (Swedish Medical
Research Council 1958), and The Netherlands (Netherlands Ministry of Social Affairs