Smoking: The Single Greatest Preventable Cause of Cancer Deaths
NEW YORK OCT 12, 2005 (Reuters Health) - In the year 2000, about 1.4 million cancer deaths, or more than one in every five cancer deaths worldwide, were caused by smoking, "making it possibly the single largest preventable cause of cancer death," Dr. Maji
"Although smoking is widely recognized as a major cause of cancer, there is little information on how it contributes to the global and regional burden of cancers in combination with other risk factors that affect background cancer mortality patterns," Dr. Ezzati and colleagues point out in the October 10th issue of the International Journal of Cancer.
To estimate site-specific cancer mortality caused by smoking in the year 2000, they analyzed data from two unique data sources -- the American Cancer Society's Cancer Prevention Study II and the World Health Organization and International Agency for Research on Cancer (IARC) cancer mortality databases.
There were an estimated 1.42 million cancer deaths worldwide in 2000. Twenty-one percent of total global cancer deaths were attributed to smoking.
Of these, 1.18 million were among men and 0.24 million among women. "The proportion of cancer deaths caused by smoking is more than 40% for men in many regions of the world like North America and Europe," Dr. Ezzati said. A total of 625,000 smoking-caused cancer deaths occurred in the developing world and 794,000 in industrialized regions.
"Currently there are slightly larger cancer deaths caused by smoking in the industrialized countries of North America, Europe, and Western Pacific," Dr. Ezzati observed, "but the rise in smoking in the developing world in the past two to three decades is expected to shift the burden to the developing world."
Lung cancer is by far the most noticeable cancer caused by smoking with about 850,000 or 71% of all lung cancer deaths caused by smoking. The next important cancers in terms of number of deaths caused by smoking are the cancers of the upper aerodigestive tract (mouth, oropharynx, and esophagus).
These estimates of smoking-attributable cancer mortality "provide an important baseline" for evaluating how tobacco control programs may contribute to reducing the global and regional burden of cancers, Dr. Ezzati and colleagues conclude.
Int J Cancer 2005;116:963-971.