Tests Show More Swine Flu Immunity In Older Folks
Scientists think its because older people have been exposed to other viruses in the past that are more similar to swine flu than more recent seasonal flus.
But the results come from complicated lab work and calculations, and its not yet clear how safe older people actually are from the new infection, federal officials said.
“We cant say,” said Dr. Anne Schuchat of the U.S. Centers for Disease Control and Prevention. So older people are advised to take the same precautions as their children and grandchildren.
In the new analysis, CDC scientists mixed the new swine flu virus with blood samples taken in the past from people in the United States and Europe to check for antibodies that would guard against infection. The samples were taken from healthy people before the new flu surfaced.
Significant protection was seen in one in three of the samples from people 60 and older, but in less than one in 10 of samples from younger adults. CDC officials said those results likely could be applied to Europe and the U.S., but they need to do more testing to find out if this would hold true in Mexico.
The number of samples was small, and the lab test hasnt been verified, so cautious CDC scientists werent willing to say it shows a clear-cut immunity in older people.
However, it could have implications for how well different people do when exposed to the swine flu virus. Also, if the government pushes swine flu shots later this year, it might mean only one dose is necessary for senior citizens.
CDC officials say the Asian flu in 1957 – which was a pandemic – and some other flu viruses after, have become common seasonal flu strains. But scientists believe that before 1957, the kind of flu that infected the country each winter was more like the new swine flu, at least in the way patients immune systems responded.
That would help explain why the new flu seems to be hitting younger people harder than older folks. Usually, the vast majority of flu-related hospitalizations are elderly people. But with the new virus, about 40 percent of those hospitalized have been in the 18 to 50 age group. For all cases – not just those hospitalized – more than 60 percent have been in people younger than 25.
But some people born before 1957 have still been getting sick from the swine flu, and health officials are urging older people to take the same precautions as everyone else.
More than 5,700 confirmed and probable cases have been reported in the United States. CDC officials say that not all people who get sick from the virus get tested, and its possible that more than 100,000 Americans have had the infection. Worldwide, roughly 11,000 cases have been reported, with at least 85 deaths.
The CDC on Thursday said it knows of nine U.S. deaths associated with the outbreak, but news reports suggest there have been at least 10.
But New England, New York and New Jersey seem to have more swine flu activity, she said.
“Just like weather, this is a local occurrence” that varies by region, said Schuchat.
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On the Net:
The CDC report: http://www.cdc.gov/mmwr
Study: Diabetes Drug Lowers Amputation Risk
About half of the patients were given fenofibrate, a drug available generically and sold as Antara, Fenoglide, Lipofen and others. The other half got fake pills. After five years, 115 patients had at least one lower limb amputation because of diabetes.
Diabetes can damage nerves and blood vessels. In severe cases, this leads to amputation. About one diabetes patient in 10 loses part of a leg.
The study, first published in 2005, aimed to see if fenofibrate prevented heart disease. It didnt.
But in this new analysis, experts found patients on fenofibrate had a 36 percent lower risk of a first amputation than those on placebo.
Patients who lost part of their legs were more likely to have heart disease, smoking, skin ulcers or previous amputations. Amputations were labeled minor if they were below the ankle and major if they were above the ankle.
The risk of minor amputations in patients without large vessel disease, the narrowing of blood vessels, was nearly 50 percent lower in the group taking fenofibrates. The risk of a major amputation was not substantially different between the two groups. Taller people were also more likely to suffer amputations.
The results were published Friday in the medical journal Lancet. The study was paid for by Laboratoires Fournier SA, now part of Solvay Pharmaceuticals, which makes fenofibrates, and the National Health and Medical Research Council of Australia.
After the studys first results, many doctors switched to statins to cut their patients heart disease risks and dropped fenofibrates.
“Fenofibrates may be re-entering the game,” said Sergio Fazio of Vanderbilt University Medical Center, who co-authored an accompanying commentary in the Lancet. “Fenofibrates cannot possibly take the place of statins, but they may earn a place next to them in diabetes treatment.”
The studys authors said their findings could change the standard treatment for avoiding amputations.
“(Fenofibrates) is the first therapy that has been shown to reduce these amputations,” said Anthony Keech of the Royal Melbourne Hospital in Australia and one of the papers authors.
Victoria King of the charity Diabetes UK said the study could help doctors find more ways of reducing diabetes-related amputations.
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On the Net:
http://www.lancet.com
Can A Mop Fight Swine Flu? Docs Say Probably Not
When hundreds of children fell ill with the virus at a Queens high school last month, authorities promptly closed the building and spent days disinfecting desks and tables and running the ventilation system on full blast.
Alarmed union officials called for the same response – evacuation and a vigorous scrub-down – when flu cases popped up this week at the citys massive jail complex on Rikers Island.
But while such cleansing efforts are undoubtedly reassuring to the public, they probably do little to control the spread of the disease, health experts said.
“It never hurts to be cleaner,” said the citys health commissioner, Dr. Thomas Frieden, “but the main way flu spreads is people not covering their mouth or nose when they cough or sneeze.”
As frightening as it can be, the influenza virus is not a hardy one. Once it leaves the body of an infected person, it usually dies within a few hours.
Any surface left alone for 24 hours is unlikely to have influenza, said Dr. Paul Biddinger, associate director of the Center for Public Health Preparedness at the Harvard School of Public Health.
“Plus, you can wipe down the surfaces today, and then someone comes in coughing and sneezing and youre infected again,” he said. “Unless you are willing every hour and every day to wipe down surfaces, it isnt going to do much good.”
The mops relative ineffectiveness in halting the spread of the swine flu virus is illustrative of a larger problem facing public health authorities trying to contain the infection: Outside of developing a vaccine, there isnt much that can be done to halt the bugs spread.
Authorities have cautioned doctors against trying to ward off infection by prescribing antivirals such as Tamiflu, warning it could deplete the supply of the medication before they know whether the epidemic is serious or could give rise to a drug-resistant form of the virus.
In the U.S., public health officials have rejected restrictions on travel and public gatherings as draconian and probably worthless, now that the virus has spread worldwide.
“Nobody wants to see a repeat of overreacting when there is no real emergency,” said Dr. Stephen S. Morse, professor of clinical epidemiology at the Mailman School of Public Health at Columbia University, citing the governments rush to inoculate people during a swine flu scare in 1976.
Some cities have reacted to outbreaks by closing schools. But even that step is questionable, experts said.
In most cases, he said, shutting a school once children have gotten ill means authorities have acted too late to halt the spread.
The U.S. Centers for Disease Control and Prevention initially advised school systems to close if outbreaks occurred, then reversed itself, saying the apparent mildness of the virus meant most schools and day care centers should stay open, even if they had confirmed cases of swine flu.
Experts have studied all sorts of other methods of trying to control flu infections, from bathing hospital waiting rooms in ultraviolet lighting for eradicating germs to using aerosolized saline droplets to interrupt transmission. Nothing has proven effective enough to try on a large scale.
The best defense, repeated again and again by doctors in recent weeks, is for people to wash their hands frequently, avoid touching their eyes, noses and mouths, cover their mouths when they sneeze or cough and stay home if they feel ill.
“Youve heard this a million times,” Morse said, “but its good advice.”
Astrazeneca E-mails Show Debate On Seroquel Risks
They say their claim is backed by internal documents released Wednesday as part of ongoing lawsuits against the company brought by patients alleging they were harmed by the blockbuster drug for schizophrenia and bipolar disorder.
Some of the internal e-mails and other documents, released late Tuesday to The Associated Press, show efforts to keep public information about Seroquel positive amid a spirited debate between the companys scientists and its marketing executives.
Ed Blizzard, a Houston attorney whose firm is helping to represent about 6,000 Seroquel plaintiffs, said data showing Seroquel was “not very effective” and had serious side effects “was either spun or skewed or outright concealed.”
AstraZeneca spokesman Tony Jewell said that since the drug was approved in late 1997, the label or detailed package insert has stated that diabetes, high blood sugar and weight gain have been observed in patients in clinical studies.
He noted that the U.S. Food and Drug Administration in the past several years has approved Seroquel as safe for new uses – bipolar mania, then bipolar depression and then an extended-release version.
Other internal e-mails and planning documents suggest the company pondered uses for which Seroquel was not approved by the Food and Drug Administration, including in dementia patients, though none of the documents indicate the company actually marketed the drug for those uses.
Doctors are allowed to prescribe drugs for unapproved uses, but drugmakers cant promote them for those uses.
A strategic plan dated 2000 suggested a “key success factor” would be to “broaden Seroquel use on and off label,” specifically targeting educational programs “to share off label data.”
Jewell said in an e-mailed statement that the documents do not recommend “inappropriate promotion” of the drug and refer to intentions to seek approval for additional indications. The statement also points out physicians often prescribe atypical antipsychotics like Seroquel off-label.
Blizzard challenged that in a conference call. “The only way they can broaden its use off-label is by marketing it to physicians,” he said.
Seroquel was AstraZenecas No. 2 drug in sales last year, with revenue of $4.5 billion.
Blizzard said U.S. District Judge Anne C. Conway in Orlando, Fla., who has been coordinating pretrial details of nearly 6,000 federal Seroquel lawsuits, recently ordered them returned to the federal courts where they were filed.
In a chain of e-mails in one document, a scientistific safety committee in June 2000 recommended removing “limited” before the words “weight gain” in the list of Seroquel side effects, because many patients gained significant weight.
Marketing staff suggested trying other explanations, such as whether patients took other drugs that could be blamed. One marketing executive, Medical Affairs Manager Richard Owen, then wrote that such a change “is potentially damaging to Seroquel.”
The change in the drugs label was finally made in 2002. That was after Barry Arnold, the vice president for clinical drug safety, complained repeatedly to the physician in charge of Seroquel drug safety about “Commercial (executives) having such an influence.”
Yet soon after the label change, AstraZeneca trademarked the term “weight-neutral” as a slogan for Seroquel, Blizzard noted. He said data showed about one-quarter of patients taking Seroquel increased their weight by more than 7 percent.
Later in 2002, Simon Hagger, global brand manager for Seroquel, e-mailed nearly 20 marketing staffers to say “we are under clear instruction from the highest level within AstraZeneca at this time not to discuss details surrounding trial 41,” outside the company. That patient study, concluded that year, found elevated levels of blood sugar.
Scientists to Inquiry Mexican Towns Flu Mystery
Scientists are returning next week to La Gloria, a pig-farming village in the Veracruz mountains where Mexicos earliest confirmed case of swine flu was identified. They hope to learn where the epidemic began by taking fresh blood samples from villagers and pigs, and looking for antibodies that could suggest exposure to previous swine flu infections.
Some experts say its pointless to worry about what happened in La Gloria now that the swine flu virus has spread around the world. But others argue that a thorough investigation could be key to preventing future epidemics.
And Mexico has another reason to care: If it can somehow rule out the possibility that La Glorias pigs infected humans, then it can tell the world it wasnt to blame for the epidemic – that the never-before-seen H1N1 swine flu virus came from somewhere else.
More than half of La Glorias 3,000 residents fell ill with flu symptoms weeks before the new virus was identified. Many found it hard to breathe, burned with fever and ached all over. About 450 of the sickest residents were diagnosed with acute respiratory infections and sent home with antibiotics and masks.
Mexican health officials initially downplayed the outbreak, saying the villagers suffered from regular flu. A 5-year-old boy was the only confirmed swine flu case among 43 villagers whose mucous samples were taken in early April. By then, most other villagers had recovered, and the virus was gone from their systems.
But some disease experts suspect swine flu was circulating more widely in La Gloria.
“I cannot understand it. I could almost bet that there were more infections related to this virus” in La Gloria, Dr. Carlos Arias told The Associated Press. Arias is leading a group of flu detectives from the Biotechnology Institute and the veterinary school of the National Autonomous University of Mexico back to the village at the invitation of the Veracruz state government.
Pigs – like people – get the flu, usually over the winter months. This new swine flu virus is unusual in that it also has infected humans and at this point has become a full-blown human flu.
La Glorias villagers believe they were sickened by the surrounding commercial pig farms, which they accuse of polluting their air and water with pig waste. But the pork industry wants a closer look at pigs raised in the villagers backyards, which may not have been vaccinated or cared for with swine flu-prevention in mind.
Arias said his team also will examine environmental and sanitary conditions in homes where pigs are raised, and make recommendations to the Veracruz government aimed at reducing the potential for human infections.
“It would be very interesting to look at the evolution of this virus and where or how easily the virus originates, reassorts and reassociates genes in an environment like La Gloria,” he said. “But also maybe that would mean that we would have to change the conditions of farming animals.”
Virginia-based Smithfield Foods, Inc., which jointly owns 72 farms in the surrounding La Gloria, said it carefully vaccinates its herd, and has found no signs or symptoms of any kind of swine flu in its herd or its employees anywhere in Mexico.
But those samples were taken weeks after most villagers had recovered from their infections – perhaps too late for the virus to show up. Even after a person or pig recovers, however, antibodies remain in their blood, evidence of the bodys immune response to the infection. And if swine flu antibodies are teased out of pigs in La Gloria, it would suggest, though not definitely prove, that the virus jumped from swine to humans there, Arias said.
Other scientists believe the new strain could have been circulating in humans long before it reached La Gloria. The new strains ancestry has ties to a pig farm in North Carolina where in 1998, scientists discovered that pig, bird and human viruses had combined in pigs to form a new strain of swine flu that also infected a handful of humans.
Most of the current strain can be traced to that combination, about 10,000 generations of the virus ago. At some point along the way, it combined with other flu strains and jumped back into humans – just when and where exactly may never be known, CDC officials have said.
A federal government research team also plans to return to La Gloria, to review health records, interview residents and search for antibodies. The boys positive test result “has to lead us to go back and look closer,” said Dr. Ethel Palacios, deputy director of Mexicos swine flu monitoring effort.
Labs capable of testing for the new swine flu strain have focused on helping sick people rather than find scientific evidence pointing to the starting point of the epidemic, which has now sickened more than 10,000 people around the world and killed 80, mostly in Mexico.
Apax, Warburg Pincus Said to Mull Bids For Drugmaker Ratiopharm
Ratiopharm, the worlds fourth-largest maker of generic medicines, may fetch as much as 3 billion euros ($4 billion), said one of the people, who declined to be identified because the details are private. Sale advisers will probably be appointed this month, the people said.
Drugmakers seeking to expand in the growing $75 billion market for lower-priced copied medicines may also be interested in Ulm-based Ratiopharm, the people said. The Merckles are selling assets to repay about 5 billion euros of debt left after the suicide of family elder Adolf Merckle on Jan. 5.
“The generics market is attractive as it has good growth propects with the upcoming patent cliff in 2011-2012 and growing purchasing power in emerging markets,” said Britta Holt, a director at Fitch Ratings in London who specializes in the health-care industry.
Founded in 1973, Ratiopharm was Germanys first generic- drug company. It sells more than 750 versions of branded medicines, including a copy of Bayer AGs original aspirin painkiller, and competes with Novartis AGs generic-drug unit and Stada Arzneimittel AG in its home market.
Banks Competing
London-based Apax owns generic-drug companies Qualitest and Vintage Pharmaceuticals in the U.S. New York-based Warburg Pincus, with about $25 billion in assets under management, also invests in the health-care industry and holds stakes in Alita Pharma and Archimedes Pharma.
Private equity firm TPG Inc. may also consider bidding for Ratiopharm, one person said. Spokespeople for Warburg and TPG in London declined to comment, as did a spokesperson for Apax in Germany.
Buyout firms have not been active in deal-making over the past six months amid a dearth of financing for takeovers.
Announced private-equity deals dropped by 67 percent in the first three months of 2009 as buyout firms coping with losses shied away from making new commitments. Deals totaled $20 billion in the first quarter compared with $60.1 billion in the same period last year, Bloomberg data show.
Banks competing to manage the transaction include the Merckle familys lenders Commerzbank AG, Deutsche Bank AG, UniCredit SpA and Royal Bank of Scotland Group Plc.
Teva, Sanofi
Israels Teva Pharmaceutical Industries Ltd. and Sanofi- Aventis SA may also be bidders for Ratiopharm, people familiar with the situation said in November.
Teva, the worlds largest generic-drug maker, wants to increase market share in Germany and is “examining and exploring every tool to grow,” Chief Executive Officer Shlomo Yanai said in a May 5 interview. Teva has more than $2.5 billion in cash to make acquisitions and could raise more funding if necessary, Yanai said.
Sanofi spokesman Jean-Marc Podvin said the company does not comment specifically on its merger and acquisition strategy.
Merckle asset sales may also include drug wholesaler Phoenix Pharmahandel AG and cement maker HeidelbergCement AG. Ludwig Merckle, Adolf Merckles eldest son and sole heir, is seeking about 400 million euros in loans to buy time to arrange the disposals.
Vivien Kremer, spokeswoman for the Merckles VEM Vermoegensverwaltung GmbH investment unit that controls Ratiopharm, declined to comment.
Gates Fights China Fakes, Drug Failure to Stem Malaria Disaster
The bout of the mosquito-borne disease, for which he tested positive, is his second in a month. The first left him comatose and in danger of dying, before medicines curbed the attack. Coursing through Sarons veins may be the strain so dangerous that health officials –and the billionaire Bill Gates — are racing to stop it from spreading before it kills millions.
In Pailin, a flood of counterfeit pills from China and elsewhere is helping to breed a superbug that resists even the most-effective medicine. The development threatens to unleash a global malaria “disaster” and undo decades of work to reduce illness, destitution and death, said Arjen Dondorp, a Thailand- based researcher.
“Its a time bomb,” said Dondorp, the deputy director of the Wellcome Trust-Mahidol University Oxford Tropical Medicine Research Programme, with headquarters in Bangkok.
The World Health Organization plans to defuse the bomb with a screening and treatment program to contain and eliminate the resistant strain. The effort, in and near Pailin, may begin next month. The program is backed by $23 million from the Bill & Melinda Gates Foundation, based in Seattle.
“Theres more money put into baldness drugs than is put into malaria,” Gates told an audience in February, in Long Beach, California. “Because the disease is only in the poor countries, it doesnt get much investment. You cant get the economies in these areas going because it just holds things back so much.”
Doom Scenario
The risk of failure raises what Dorndop calls a “doom scenario.” In that sequence of events, migrant workers would first carry the bug to Thailand, Myanmar and India. Later the strain would spread to Africa, which already has 90 percent of the worlds malaria cases.
“We rang the warning bell in 2005 and nobody believed us,” said Pascal Ringwald, the Geneva-based WHOs leading specialist in the malaria parasites ability to resist drugs. “Many people were skeptical.”
The doom scenario may be a decade away from materializing, giving the world time to prevent it, said Charles Delacollette, the head of WHOs Mekong Malaria Programme, which covers Cambodia, Laos, Myanmar, Thailand, Vietnam and part of China.
“We dont have many alternatives” to the antimalarial drug artemisinin, to which the parasite is becoming resistant in western Cambodia, Delacollette said in an interview in Bangkok. “That drug should be protected.”
Interpol Operations
Chemical analysis of pills bought in Cambodia, Laos, Myanmar, Thailand and Vietnam found several other pharmaceutical ingredients, charcoal, and a precursor of the illicit drug ecstasy, according to an account of Operation Jupiter published in the journal Public Library of Science Medicine. Also present were spores and pollen from trees common in southern China, suggesting that at least some of the drugs were made there, the authors said.
“The evidence we have at the moment suggests China and India are sources of fake medicines, including in the case of China, fake anti-malarials,” said Paul Newton, a University of Oxford researcher who monitors counterfeit malaria drugs from an office in Vientiane, Laos.
Market Forecast
Interpols actions hardly dented the global market for counterfeit pharmaceuticals, which may reach $75 billion in 2010, an increase of more than 90 percent from 2005, according to estimates by the Center for Medicine in the Public Interest, a nonprofit organization based in New York. WHO says fakes, typically cheaper than real drugs, may account for as much as 30 percent of all medicines in developing nations.
“Were talking about sophisticated, big syndicates, people who are very well organized,” said Aline Plancon, the Interpol officer who coordinated the operations. “Its just insane. Theyre making too much money, theyre betting too much on the health of people. Well do it again and again.”
Deadly Disease
Malaria strikes about 250 million people each year and kills more than 880,000, making it the worlds most lethal mosquito-borne disease, according to WHO.
Glaxosmithkline Offers 50 Million Doses Of Pandemic Vaccine to Who
The offer was made during a meeting between U.N. officials, vaccine makers and other health experts to discuss how to provide vaccines to poor countries if the swine flu outbreak goes global. But it has not been finalized by either GlaxosmithKline PLC or WHO.
On Tuesday, U.N. head Ban Ki-moon and WHO chief Margaret Chan appealed to drugmakers to save some of their pandemic vaccines for poor nations. Several vaccine makers in developing countries have also offered to share some of their vaccines, but their production capacity is limited.
Glaxo spokesman Stephen Rea said that in addition to the vaccine donation, the company will also reduce its pandemic vaccine prices for developing countries.
No pandemic vaccine exists yet, but pharmaceuticals say they can begin production immediately once they get the vaccines key ingredient, a “seed stock” based on the virus. That is being developed by the United States Centers for Disease Prevention and Control, and should be available by mid-July, WHO said.
Once vaccine makers receive the seed stock, a vaccine should be available in several months.
Glaxo has also signed agreements with various countries to provide them with pandemic vaccine as soon as its available. It has promised to provide 60 million doses for Britain, 12.6 million doses for Belgium and 5.3 million doses for Finland. It is also waiting to finalize a deal with France that would provide them with 50 million vaccines.
So far, other big vaccine makers have not followed suit with offers to donate. Swiss pharma giant Novartis AG said its position remained unchanged since the question of vaccine access for poor countries first came to the fore in connection with the H5N1 bird flu.
“Its pretty much the status of discussions two years ago,” spokesman Eric Althoff said.
“I dont think that all of the answers are there yet.”
Early Treatment With Anti-aids Drugs Cuts Demise Rate In Half
In the past, doctors focused first on controlling the AIDS- related illness and delayed prescribing antiviral drugs lest the combination cause side effects or be hard for patients to manage, said Andrew Zolopa, director of the AIDS clinical trial unit at Stanford University School of Medicine.
In the U.S., 60,000 to 70,000 new cases of AIDS are diagnosed each year, and half of the patients have advanced disease, Zolopa said in a telephone interview. His findings, published today in the journal PlOS One, may resolve a long- running issue in AIDS treatment by showing that patients have a better chance of surviving if theyre given antiviral drugs from the start.
“This study makes clear that these medications are life- saving in this patient population,” said Brad Hare, medical director of the Positive Health Program at San Francisco General Hospital, run by the University of California, San Francisco, in a May 15 phone interview. “In people who are very sick from their HIV, initiating treatment as quickly as possible — even during treatment for another infection — can be life-saving.”
Zolopa, lead author of the new study, said he started the research because he was unable to answer a question from doctors at Stanford Hospital. They wondered if they should treat HIV- infected patients with antiviral drugs if they were already being treated for infections like pneumonia or meningitis. These drugs have become the mainstays of AIDS treatment.
I Dont Know
“My response was always the same: I dont know,” said Zolopa. “Id come by, see the patient and say well treat the infection first, get him out of acute crisis and let him go home. Then wed do an assessment and make sure he was ready to start and comply with antiretroviral drugs.”
“That answer was wrong,” Zolopa said.
By the time patients would come back for a follow-up appointment and get started on the new medications, as many as three months could go by, and their immune systems might be further compromised, leaving them more susceptible to new problems, Zolopa said.
In Zolopas study, 282 HIV-infected patients who sought treatment between 2003 and 2006 for an AIDS-related conditions such as pneumonia, meningitis, lymphoma or bacterial infections were treated with drugs. Many of the patients hadnt previously been diagnosed with HIV and didnt know they had it.
Deaths Within Six Months
In addition to being treated for their acute infection, half the patients were put on antiviral drugs within two weeks, while the others didnt start antiviral medication for an average of 45 days.
Most patients who died or got worse did so in the first six months, Zolopa said.
When Michael Saag learned last week that a burn patient in an Alabama intensive care unit was infected with the AIDS virus, he knew what to do because hed heard early results of this research.
Trauma doctors at the University of Alabama at Birmingham Hospital were treating the man with drugs to combat bacterial pneumonia. Saag, director of the Center for AIDS Research at the University of Alabama at Birmingham, found the man also had HIV and began giving him the antiviral drugs that have become the mainstay of AIDS treatment.
“These data are very compelling and in our neck of the woods, weve changed our practice,” Saag said in a May 14 telephone interview. “I think it will save some lives.”
— Editors: Donna Alvarado, Kurt Heine
Study Links Cigarette Adjustments to Rising Lung Risk
Up to half of the nations 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.
Its 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.
Thats 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 Australias lung cancer, he said.
While the nations total lung cancer cases have inched down as the number of smokers has dropped in recent years, the study suggests an individual smokers risk of getting cancer is higher.
Its 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 doesnt rule out a role for deeper inhaling, cautioned Dr. Michael Thun of the American Cancer Society: “Theres several strong suspects in the lineup. They may have acted in combination.”
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 tobaccos many risks – it causes heart disease and other killer diseases, too.
“If you reduce someones (lung cancer) risk by 10 percent, thats not really meaningful for an individual,” he said. “The goal still is to get them to stop.”