Nov 29 In eight European and Scandinavian
countries, 270,000 people are diagnosed every year with cancers
caused by smoking, according to a European study.
Smoking is known to be a major contributor to a variety of
cancers, including lung, colon and bladder cancers, and
understanding how great the burden of smoking is on cancer rates
is important for developing prevention strategies, said Antonio
Agudo, the lead author of the study.
"These results tell us that (the) contribution of tobacco
smoking to cancer is substantial, and that, in spite of
substantial efforts put forward to reduce smoking in European
countries, the overwhelming importance of cigarette smoking on
cancer risk is still of public health concern, and a priority
from the point of view of prevention," said Agudo, a researcher
at the Catalan Institute of Oncology in L'Hospitalet de
He and his colleagues, as part of the European Prospective
Investigation into Cancer and Nutrition (EPIC), gathered
information on more than 440,000 residents of Denmark, France,
Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden
and the United Kingdom.
The researchers, whose findings appeared in the Journal of
Clinical Oncology, began tracking the participants between 1992
and 2000. None had been diagnosed with cancer.
Over an average of 11 years of follow up, the team found
that 14,563 people who were exposed to tobacco smoke developed a
type of cancer considered to be fully or partly caused by
tobacco exposure. This is equivalent to 270 diagnoses out of
every 100,000 people.
Current smokers were 2.6 times as like as those who had
never smoked to develop a tobacco-related cancer and ex-smokers
had 1.5 times the risk.
Nearly 4,500 people were diagnosed with colon or rectal
cancer, about 3,000 with lung cancer and 1,850 with lower
urinary tract cancer. Other types of tobacco-related cancers
were less common but included stomach, cervix, mouth, kidney,
pancreas and a form of leukemia.
Although each of these cancers has been associated with
smoking, not all of the cases were caused by it.
The researchers calculated the "attributable fraction," or
the proportion of cancer cases likely blamed on cigarettes, and
determined that, overall, 35 percent were caused by smoking.
For some types of cancers, such as lung and larynx, the vast
majority - more than 80 percent - were caused by smoking. A
smaller proportion of others, such as kidney cancers at eight
percent and pancreatic cancers at 13 percent, were caused by
Across the eight countries with data available on both men
and women, about 1.5 million new cancer cases are diagnosed each
year - half of them tobacco-related.
Given the proportion of those attributable to smoking, the
group calculated that 270,000 cancer cases each year in those
countries are due to cigarettes - a number that Agudo said was
"not far from our expectations."
Prabhat Jha, a professor at the University of Toronto who
was not involved in the study, said the findings are consistent
with estimates of how many deaths are caused by smoking in
Europe but said the numbers could be underestimates.
He added that in wealthy countries, such as those in Europe
and North American, the rates of smoking-related cancers and
deaths have declined substantially, while cancer rates in China
and India are rising.
Nevertheless, "This study should support greater EU efforts"
to curb smoking, he added.
(Reporting from New York by Kerry Grens at Reuters Health,
editing by Elaine Lies)