A View of Their Lung Damage May Help Smokers to Quit
TOBACCO IS the single most avoidable cause of death. Yet by the end of this century, smoking, if unchecked, will kill a billion people.
"That's one percent of all humans who have ever lived since the evolution of Homo sapiens," said Penn State science historian Robert Proctor.
Proctor calculated the smoking death toll in the October issue of a new journal, Nature Cancer Reviews. Even if every smoker on the planet were to quit tomorrow "the death toll would still be in the tens of millions," Proctor concluded in the study.
Of course, there's no indication that quitting will happen, given the steady rise in smokers worldwide, thanks to the U.S. tobacco industry's innovative marketing strategies to poor countries. Right now, there are 1.25 billion smokers in the world, or about one- third of the world's population age 15 and older. About 800 million of them are from developing countries, according to the World Health Organization. And while smoking rates are steadily declining in the wealthier nations, they are rising about 3.4 percent per year in developing countries, WHO says.
What's almost as stunning is the fact that lung cancer was once a rare disease. It was not even described medically until the 18th century, and only 140 cases had been reported in the world medical literature by 1898, Proctor said.
"It was so incredibly rare that when a doctor saw a case he would call in all the students to observe. He would tell them this would probably be the only case they would see - and that was as late as World War I," Proctor said.
Now, of course, lung cancer is the leading cause of cancer deaths in this country. In American men it accounts for 30 percent of all cancer deaths; in American women, 25 percent, according to the American Cancer Society. About one in five deaths from heart disease - the No. 1 killer in this country - are caused by tobacco, according to the American Heart Association. And then there are the 1.8 million Americans with emphysema, which is caused by smoking in 80-90 percent of cases. Worldwide, the only two major causes of death that are increasing rapidly are HIV and tobacco, according to the British anti-smoking group Action on Smoking and Health.
Given how hard it is for many people to quit smoking and how hard it is to detect lung cancer until it is advanced and not easily curable, all of this is depressing. But there was a small study published in October in the journal Preventive Medicine that gives some tiny reason for hope.
Researchers at Manhattan's Weill Medical College of Cornell University and Memorial Sloan-Kettering Cancer Center are part of a group of 11 metropolitan-area hospitals - including Stony Brook University Hospital - participating in a study to determine if low-dose CT scanning is effective in detecting early lung cancers.
Called New York Early Lung Cancer Action Program, the study is recruiting 10,000 people 60 and older who smoke or who used to smoke one pack a day for 10 years or two packs a day for five years and have never had cancer.
In an earlier study of 1,000 smokers, this special CT scan was shown to pick up early lung cancers missed 85 percent of the time by chest X-rays, the current means of detecting lung cancer. The purpose of this larger study is to see if that percentage holds true. Results are expected in 2003.
The researchers began noticing anecdotally that smokers in the study who had received their CT scan were more likely to quit or cut back on smoking. So, said Dr. Claudia Henschke of Weill Medical College, the principal investigator in the project, they decided to see if this was true.
In the Preventive Medicine study, the researchers in the New York cancer action program called 134 smokers in the study who had had the lung CT scan. Of those, 23 percent reported they had quit and 27 percent had cut back on their smoking after the scan. This is a lot higher percentage than the usual 7 percent smoking quit rate in the general population and about the same as that seen in people using the nicotine patch, Henschke and her colleagues said in the study.
In most cases, cancers were not found, but other lung changes - such as early emphysema - were powerful motivators, Henschke said. One woman told the researchers, "Every time I lit up I thought about what my lungs looked like," Henschke said.
It's easy to poke holes in a study like this: It's small, people can lie and someone who signs up for such a study may be already motivated to quit smoking. Nevertheless, it shows that if people see what they are doing to themselves, it can have an impact.
"Getting a visible glimpse of damage to your lungs is apparently a fairly powerful thing," said Dr. Robert Smith, director of cancer screening at the American Cancer Society.
Maybe more powerful than imagining 1 billion dead smokers.
Stony Brook Hospital is the Long Island site participating in NY-ELCAP. Researchers are especially interested in recruiting minorities. For more information call 866-NY-ELCAP.