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WASHINGTON – It may be riskier on the lungs to smoke cigarettes today than it was a few decades ago — at least in the U.S., says new research that blames changes in cigarette design for fueling a certain type of lung cancer.
Up to half of the nation’s lung cancer cases may be due to those changes, Dr. David Burns of the University of California, San Diego, told a recent meeting of tobacco researchers.
It’s not the first time that scientists have concluded the 1960s movement for lower-tar cigarettes brought some unexpected consequences. But this study, while preliminary, is among the most in-depth looks. And intriguingly it found the increase in a kind of lung tumor called adenocarcinoma was higher in the U.S. than in Australia even though both countries switched to so-called milder cigarettes at the same time.
“The most likely explanation for it is a change in the cigarette,” Burns said in an interview — and he cited a difference: Cigarettes sold in Australia contain lower levels of nitrosamines, a known carcinogen, than those sold in the U.S.
That’s circumstantial evidence that requires more research, he acknowledged.
But anti-smoking advocates are citing the study as Congress considers whether the Food and Drug Administration should regulate tobacco, legislation that would give the agency power to decide such things as whether to set caps on certain chemicals in tobacco smoke.
Smokers once tended to get lung cancer in larger air tubes, particularly a type named “squamous cell carcinoma.” Then doctors noticed a jump in adenocarcinoma, which grows in small air sacs far deeper in the lung. Initial studies blamed introduction of filtered, lower-tar cigarettes. When smokers switched, they began inhaling more deeply to get their nicotine jolt, pushing cancer-causing smoke deeper than before.
Burns’ study, presented at a meeting of the Society for Research on Nicotine and Tobacco, took a closer look. He compared smoking behaviors of different age groups over four decades — how much they smoked, when they started, when they quit — and how cancer-risk changed.
The risk of squamous cell carcinoma stayed about the same over those years, Burns found. But adenocarcinoma rose. It makes up 65 percent to 70 percent of newly occurring U.S. lung cancer cases, but no more than 40 percent of Australia’s lung cancer, he said.
While the nation’s total lung cancer cases have inched down as the number of smokers has dropped in recent years, the study suggests an individual smoker’s risk of getting cancer is higher.
It’s well known that cigarettes differ from country to country, because of different tobacco crops grown locally and smokers’ varying tastes. Nitrosamines are a byproduct of tobacco processing and levels vary for several reasons, including differences in curing practices.
Australian cigarettes contain about 20 percent of the nitrosamine content of U.S. cigarettes, making the chemical a prime suspect, concluded Burns, who has been scientific editor of several surgeon general reports on tobacco.
That doesn’t rule out a role for deeper inhaling, cautioned Dr. Michael Thun of the American Cancer Society: “There’s several strong suspects in the lineup. They may have acted in combination.”
Philip Morris USA spokesman David Sutton called the study speculative and hard to evaluate until it’s published in a medical journal, something Burns plans to do.
Still, Philip Morris, which supports FDA tobacco regulation, began taking steps with its growers in 2000 that have yielded “significantly lower” nitrosamine levels in recent years’ supplies, Sutton said.
Be careful in assuming lower-nitrosamine cigarettes are less lethal, said Dr. Neal Benowitz of the University of California, San Francisco, a well-known tobacco expert. Lung cancer is only one of tobacco’s many risks — it causes heart disease and other killer diseases, too.
“If you reduce someone’s (lung cancer) risk by 10 percent, that’s not really meaningful for an individual,” he said. “The goal still is to get them to stop.”
AmericanHealthOptions reminds that Zero Nicotine is one of top smoking cessation aids.
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GENEVA – Dozens of countries urged the World Health Organization to change its criteria for declaring a pandemic, saying the agency must consider how deadly a virus is — not just how far it spreads across the globe.
Fearing a swine flu pandemic declaration could spark mass panic and economic devastation, Britain, Japan, China and others asked the global body on Monday to tread carefully before raising its alert. Some cited the costly and potentially risky consequences, such as switching from seasonal to pandemic vaccine, even though the virus so far appears to be mild.
Although no formal changes were made Monday, WHO said it would listen to its members’ requests.
“It’s certainly something we will look at very closely,” said Dr. Keiji Fukuda, WHO’s flu chief.
The alert for swine flu is now at phase 5, which means the virus is spreading unchecked inside at least two countries in a single region. Under the existing rules, phase 6 indicates outbreaks in at least two different regions of the world and that a pandemic is under way.
“We need to give you and your team more flexibility as to whether we move to phase 6,” Britain’s Health Secretary Alan Johnson told WHO Director-General Dr. Margaret Chan, a public health veteran who has made combatting the outbreak her top priority since the new virus appeared in North America last month.
Chan warned that swine flu could pose a grave threat to humanity even though the fatality rate is low, with 76 known deaths out of 8,829 confirmed cases in 40 countries. That total does not include Greece, which reported its first confirmed case on Monday.
“This virus may have given us a grace period, but we do not know how long this grace period will last,” Chan said. “No one can say whether this is just the calm before the storm.”
Japan reported the largest jump from just four cases over the weekend to more than 170 cases, health officials said Tuesday. Most involved teenagers who had not traveled overseas.
Spain and Britain have the highest numbers of cases in Europe, reporting 103 and 101 cases, respectively.
A pandemic announcement would likely have severe economic consequences: It could trigger expensive trade and travel restrictions such as border closures, airport screenings and quarantines.
Governments also fear mass panic, social disruption and overwhelmed health systems. Extraordinary measures such as large-scale pig slaughters like the recent one in Egypt could be taken, even if they aren’t scientifically justified.
Mexico, which has suffered the most deaths and virtually shut down its economy for several days in response to the outbreak, urged WHO to reconsider its pandemic scale.
“People don’t understand what 4, 5 or 6 means,” Mexico’s Health Minister Jose Angel Cordova told reporters. “They think that when you go to a higher level things are worse.”
U.S. Health and Human Services Secretary Kathleen Sebelius told The Associated Press she wanted more information on the proposal before taking a position, but she was impressed how many countries supported it. Still, in a speech to the assembly she noted that each day 26,000 children will die from poverty and preventable diseases. Swine flu is a long way from causing that kind of devastation.
So far the virus appears to be mild, though scientists are concerned that many of the more severe symptoms have turned up in younger people, especially in Mexico. Flu is normally most dangerous to babies and the elderly.
WHO chief Chan noted that the disease could combine with other flu strains, including the lethal H5N1 bird flu virus which hasn’t spread much among humans.
The signal for starting pandemic vaccine production has yet to be given, but it is essential that countries use their stockpiles of drugs wisely, she said. WHO has said two anti-viral drugs, Tamiflu and Relenza, have been effective against the new swine flu.
“It is absolutely essential that countries do not squander these precious resources through poorly targeted measures,” Chan said.
Chan and U.N. Secretary-General Ban Ki-moon are scheduled to meet with senior representatives of pharmaceutical companies Tuesday to discuss the vaccine question. The U.N. declined to name the companies but major vaccine producers include Sanofi-Aventis, GlaxoSmithKline and Baxter International.
Key issues include: how soon can a pandemic vaccine be produced, and how much of it will be available to each country. Many governments, including Britain, have already signed large advance orders, potentially depriving poorer countries of a chance to buy their own stock.
AmericanHealthOptions reminds that most common medication for fighthing against swine flu is Tamiflu.
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