Smoking and Lung Cancer

Everyone knows that smoking causes lung cancer. But how big are your risks of getting lung cancer if you smoke and what is it about tobacco smoking that causes lung cancer?

For some illnesses caused by smoking, smokers have a 50% or a 100% greater chance if getting that illness than never smokers. Stomach cancer and pneumonia are like that. A 100% greater risk doesn’t mean 100% chance of getting the illness, it means double the chances of getting the illness as compared with the chances if you never smoked.

For lung cancer, the increased risks are much greater. So a man who continues to smoke until he dies is has 2300% increased risk of dieing of lung cancer: I.e. he is 23 times more likely to die of lung cancer, as compared with if he had never smoked. Of course, the overall size of that risk is influenced by how common the disease is. A lifelong non-smoker has less than half of one percent chance of dieing of lung cancer by the age of 75. A smoker who quits smoking by age 40 has a 6% chance of dieing of lung cancer by age 75. If the smoker keeps smoking until they die or reach age 75, then they have a 16% cumulative risk of dieing of lung cancer. These risks are amazingly big, when one remembers that for the smoker to get lung cancer they also have to survive and not be killed by one of the other common illnesses caused by smoking (e.g. COPD, heart-attack etc).

Smoking causes lung cancer because the smoke itself contain known carcinogenic chemicals such as benzo(a)pyrene and NNK. As these chemicals are deposited into the lungs year on year they cause DNA damage, oxidative stress and inflammation, which promote the initiation and growth of tumors. It is essentially the DNA damage, and the inability of the body to repair that damage, that results in cells starting to divide and multiply in a deviant way that ends up growing into a malignant tumor. Because the lungs are such essential organs for life (ie. healthy lungs are necessary for breathing) and because lung cancer is not easy to detect and cure at an early stage, lung cancer is very often fatal, with a 5-year survival rate around 15%. In many cases the cancer metastasizes and affects other organs of the body.

Great efforts continue to try to develop new methods of detection and cure for lung cancer. But right now the best interventions we have are those that prevent it occurring in the first place, by reducing initiation of smoking or enabling addicted smokers to quit before they develop lung cancer. By far the best thing you can do to dramatically reduce your risks of developing lung cancer, is to avoid all inhalation of tobacco smoke.

If you are interested in reading about the health effects of smoking in greater detail I recommend a recent chapter on that topic by Foulds and colleagues (2008) that can be downloaded from: http://www.tobaccoprogram.org/staffarticles.htm

The 2004 US Surgeon General’s Report is an extremely comprehensive review of the effects of smoking on health which can be accessed in various formats at:
http://www.surgeongeneral.gov/library/smokingconsequences/

Labels: cigarette smoking, jonathan foulds, lung cancer

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Lung Cancer, Spiral CT and Tobacco Industry Funding

An interesting article was published in the New York Times yesterday, revealing that one of the studies reporting the most positive effects on the potential of spiral CT in detecting early stage lung cancer, was funded by the tobacco industry. The article raises questions about the motivations from the tobacco industry to fund such a study, and the reasons for lung cancer researchers accepting research funding to investigate lung cancer screening from the tobacco industry.

In fact, the story is a little more complicated. The study was part funded by an organization called, “Foundation for Lung Cancer: Early Detection, Prevention & Treatment”. The New York Times examined tax records and discovered that this foundation is mainly funded via a grant from Ligett Group, which makes a number of brand-name cigarettes. The article suggests the possibility that the foundation may have been set up to hide the original source of the funding, and numerous senior cancer researchers and journal editors stated that they were shocked to find out that the research had been funded by a tobacco company.

Within the medical research community there is wide acceptance of pharmaceutical company funding for research and educational purposes. While we are all aware of cases of unethical behavior by pharmaceutical companies, their overall mission is to improve health and is entirely consistent with that of academic medical researchers. The tobacco industry, on the other hand, has a long history of trying to misuse research to sell more cigarettes: virtually the only legal consumer product that is lethal to the user when used as intended. So many academic institutions (including my own, the School of Public Health at the University of Medicine and Dentistry of New Jersey) have an explicit policy of not seeking or accepting funding from the tobacco industry, other than that resulting from a law suit against the industry. The other issue brought up by the NY Times article is that of disclosure of funding sources. There is a sense that while we all may have a right to earn a living as we see fit, when it comes to medical research and informing the public about health matters, we should try to be up front in disclosing the sources of our funding.

Sometimes this is more difficult than you might expect. For example, for some time now I have taken to sending a rather long statement about my own funding to journals when I submit a paper for publication. But the journal editors make the decision as to what is most relevant to print as a statement of funding or potential conflict of interest. I have submitted the same statement to Healthline.com and requested more than once over a period of almost 9 months that it be placed on my blog home-page in the interest of transparency, but the site hasn’t yet managed to post it. So sometimes its harder to be transparent than one might think. I happen to feel this is an important issue and so I’m attaching my own funding statement to the bottom of this article. I hope that eventually the healthline managers also take this issue seriously and get round to updating my bio as requested.

You can find the New York Times article at:
http://www.nytimes.com/2008/03/26/health/research/26lung.html?pagewanted=2&_r=2&th&adxnnl=1&emc=th&adxnnlx=1206536513-CFXEqFJHZcmgnSxsKwMNfw

Funding statement. This statement provides a brief summary of the sources of funding for Jonathan Foulds PhD

Jonathan Foulds is primarily funded by a grant from New Jersey Department of Health and Senior Services. His other recent research funding (also as P.I.) is from the Cancer Institute of New Jersey, the Rutgers Community Health Foundation and the Robert Wood Johnson Foundation. He has worked as a consultant, as a promotional speaker and received honoraria from pharmaceutical companies involved in production of tobacco dependence treatment medications (e.g. Pfizer, Novartis, GSK, Celtic Pharma) as well as a variety of agencies involved in promoting health (e.g. W.H.O., N.I.H., etc). Some of these agencies have provided sponsorship funds for educational events conducted by the program he directs. The program he directs (Tobacco Dependence Program at UMDNJ-School of Public Health) conducts trainings and charges health professionals and their organizations for providing these. He has also worked as an expert witness in litigation, including for plaintiffs in law suits against tobacco companies. He has not received any funding from the tobacco industry other than deposition fees from defendants attorneys in litigation against the tobacco industry (i.e. while acting as a witness for the plaintiffs). He is paid for writing a regular column on a health website: http://www.healthline.com/blogs/smoking_cessation/ .

Labels: cigarette smoking, funding, jonathan foulds, lung cancer, spral CT, tobacco industry

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Buy cigarettes on the internet? Expect a large invoice.

As many states raise the excise tax on cigarettes, smokers in high-tax states are sometimes tempted to go online and save money by ordering from an out-of-state discount store to avoid paying the tax.

Many states (34 by 2006) have now passed laws governing these types of sales, and at least 5 have banned direct to consumer shipment of cigarettes. Because of the myriad of complex state and federal laws affecting this aspect of business, many of the (over 700) vendors selling cigarettes on the internet have been found to be in breach of at least one state law. This breach makes them open to prosecution, and one of the common requirements during such prosecutions is that they turn over records of all their orders and deliveries. When the state gets access to this information, it can be used to bill these individuals for unpaid taxes. I’ve known smokers who received a bill for thousands of dollars in unpaid cigarette excise taxes after purchasing online for a long time. I also read a newspaper article about a woman who received a bill for her husband’s unpaid taxes for internet cigarette purchases, after the husband had died of lung cancer. Whether or not you agree with this practice, you should at least be aware of the risks. Rather than run the risk, why not make a serious attempt to quit smoking? Think of all the other things you could buy on the internet with the money you save on cigarettes!

Labels: cigarette sales, cigarette tax federal health insurance children, jonathan foulds, online

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How have New York and New Jersey reduced smoking?

From 1992-2002 cigarette smoking prevalence in New York City remained relatively stable, with around 21-22% of adults being smokers. However, in 2002 the city began to implement a comprehensive five-point tobacco control plan, as follows:
1. Increased city cigarette tax from 8c to $1.50 per pack.
2. Implement comprehensive smoke-free workplace legislation (including bars and restaurants).
3. Educate healthcare providers to provide treatment for smokers.
4. Provide free nicotine patches via the quitline.
5. Implement a comprehensive TV-based anti-smoking media campaign designed to motivate quit attempts.

The New York City effort was also helped by wider national tobacco control activities, New York state media activities, and steeper increases in cigarette taxes in near-bye New Jersey, which served to reduce options for cross-border purchasing.

The result was a decrease in adult smoking prevalence from 21.5% in 2002 to 17.5% in 2006, amounting to 240,000 fewer smokers in the city. Youth smoking also decreased from 14.8% to 11.2% from 2003-2005 in New York City.

The state-wide ban on smoking in workplaces or public places, implemented in 2003, resulted in an 8% drop in hospital admissions for myocardial infarctions, and a direct healthcare cost saving of $56 million in one year.

In addition to the direct benefits to the health of the people of New York, these policies have improved health among future generations by reducing youth smoking onset, improved the state’s and city’s budget by bringing in additional cigarette tax revenues, allowed the people of New York to go out in greater numbers to enjoy the excellent bars and restaurants without having to inhale carcinogens or stink of tobacco, and increased the income to those establishments as more people started to use them after they went smoke-free.

It is hard to imagine better, more cost-effective public policy, other than by boosting the return on investment by investing even more heavily in tobacco control policy implementation (as New York State recently decided to do). Other cities and states would do well to observe the lessons and implement similar policies designed to reduce smoking.

Meanwhile, in my home state of New Jersey, we have also had considerable success in reducing adult cigarette smoking prevalence from around 21% in the 1990s to 17.4% in 2005. In 2004 the average adult in the US consumed 69 packs of cigarettes per year, whereas the average adult in New Jersey consumed 43 packs. Among high-schoolers, the prevalence of monthly cigarette smoking also reduced from 21% in 2001 to 16% in 2006.

New Jersey has also implemented a comprehensive tobacco control program including the highest state cigarette tax in the country, comprehensive smoking cessation services, youth-led tobacco control activities, age-of-sale increased to 19 years, and then implementation of comprehensive smoke-free workplace legislation in 2006.
Data and information on changes in tobacco use in New Jersey can be found at: http://www.state.nj.us/health/as/ctcp/research.htm

Further details about changes in smoking in New York City can be found at:
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5624a4.htm

A summary of reductions in heart attacks in New York can be found at:
http://www.ajph.org/cgi/content/abstract/97/11/2035

Labels: cigarette smoking, jonathan foulds, New Jersey, New York

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Why Chantix may reduce alcohol consumption.

Some of those people who have posted comments on my blog have commented that when they were using Chantix (varenicline) their interest in drinking alcohol or smoking marijuana also decreased. There are a couple of obvious potential mechanisms for that effect. Firstly, we are all familiar with the association between smoking tobacco and other substance use. Smokers are much more likely to take other substances than non-smokers, and when a smoker has a drink it often increases their desire to smoke and vice versa. So Chantix may reduce other substance use simply by helping take out cigarettes as a trigger. In addition, there have been reports that in a small but significant proportion of cases, Chantix use has coincided with a period of low mood or depression. So it is plausible that those affected in this way may lose part of their taste or enthusiasm for a number of activities they had previously enjoyed (including alcohol).

But there is also some evidence from studies of experimental rats, which suggests that varenicline (Chantix) may have a more direct effect on alcohol consumption. Last year, Dr Pia Steenland and colleagues at University of California published a paper in the prestigious journal, “Proceedings of the National Academy of Sciences” Their study found that animals who became used to drinking ethanol (alcohol) and were then treated with varenicline showed reduced alcohol-seeking behavior, and reduced alcohol consumption, without having any effects on water or sugar consumption. The authors concluded that,
“The finding that varenicline decreased ethanol consumption in chronically exposed ethanol-consuming rats suggests that varenicline may serve as a therapeutic treatment to reduce alcohol consumption in alcoholic subjects; however, this remains to be examined.”

This means that these results in animals are suggestive of a potential effect in humans, but proper clinical trials in humans will be needed. So these reports of reduced interest in drinking alcohol among people taking Chantix for smoking cessation, may have a real pharmacological basis that may ultimately be clinically useful for people with alcohol problems.

The full study can be viewed at:
http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17626178

Labels: alcohol problem relapse, champix, Chantix, jonathan foulds, smoking cessation, varenicline

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Wearing the patch prior to quitting

The normal recommended way to use the nicotine patch is to choose a “Target Quit Day”, smoke your last cigarette and get rid of all your tobacco the night before it, and then start wearing the patch instead of smoking on the morning of your quit day. The nicotine patch helps with smoking cessation by reducing the severity of nicotine withdrawal symptoms and cravings.

The labeling on the nicotine patch recommends against smoking (or using any other nicotine products) while wearing the patch. I’ve discussed previously that there is now good evidence suggesting that using another nicotine replacement therapy (e.g. nicotine gum or inhaler) while wearing the patch may aid smoking cessation. This month a new study was published by Drs Shiffman and Ferguson from Pittsburgh, which suggests that wearing nicotine patches for at least two weeks prior to the target quit date actually increases quit rates one month and six months later. Shiffman and Ferguson combined the data from four randomized trials comparing outcomes for those wearing the patch while smoking before trying to quit, with those wearing placebo or no patches prior to the quit day. The results found that those who wore the patch for at least two weeks before their quit day were almost twice as likely to still be not smoking six months later.

It seems that smoking while wearing the patch for a few weeks doesn’t really add anything to the usual risks of smoking. But perhaps the main question is why this helps people quit? We don’t know for certain but I suspect that wearing the patch while smoking for a couple of weeks serves to reduce the rewarding effects of smoking. The continuous supply of nicotine from the patch desensitizes nicotine receptors and ensures that only a few receptors are ready to be stimulated at any one time. This may reduce the down-stream stimulation of the brain’s reward pathway (and release of dopamine) when the person smokes. Perhaps a couple of weeks of less rewarding smoking is enough to weaken the strength of the addiction?

As mentioned above, this is not yet normal practice, but it shows that a more flexible approach to the use of nicotine replacement therapy can often obtain better results.

Reference:
Shiffman S, Ferguson SG. Nicotine patch therapy prior to quitting smoking: a meta-analysis.Addiction. 2008 Apr;103(4):557-63.

Labels: jonathan foulds, nicotine patch, smoking cessation

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Smoking and lung function

Chronic obstructive pulmonary disease (COPD) is characterized by gradually worsening airflow obstruction interfering with normal breathing, leading to disability and death. Between a quarter and a half of long term smokers develop COPD. Smokers are 13 times more likely to die from COPD than never-smokers, and in recent years more women than men are killed by COPD in the United States.

Relatively quick and simple lung function tests can detect likely lung damage (spirometry) from about age 35 onwards – i.e. after about 20 years of smoking. One of the standard measures is known as “FEV-1” which is the persons maximum total “Forced Expiratory Volume in one second”. To measure this, you take as deep a breath as you can and then blow it as forcefully as you can into a machine, which measures the total volume blown out in one second. For most of us our lung function declines very slowly with age from about age 25, such that it is still pretty good even into our 80s and beyond. Smoking speeds up that decline, leading to disability and death at a younger age, particularly in those susceptible to COPD. Stopping smoking at any age slows down the decline in lung function to that of a never smoker. We also know from the US Lung Health Study that lung function actually improves in the few years immediately following stopping smoking. For people who smoke or have any breathing problems, it makes sense to have your lung function checked. Note that in most cases it will be normal. This should not be interpreted as a sign that you can keep smoking without harming your health. It just means that your lung function hasn’t been impaired yet, and of course says nothing about your risks of cancer, cardiovascular disease etc.

An interesting paper was just published in the BMJ by Dr Gary Parkes and colleagues, showing that smokers who had their lung function measured and explained to them in a specific way, including feedback on their “lung age”, were more likely to have quit smoking a year later than those who had their lung function measured and fed back in the standard way (14% vs 6%). The “lung age” is the age of the average person who has an FEV1 equal to that individual. A typical middle-aged smoker has the lung age of someone 10 years older.

You can access the whole article by Dr Parkes for free at:
http://www.bmj.com/cgi/content/full/bmj.39503.582396.25v1

The single best thing a smoker can do to improve their lung function and live a longer healthier life is to stop smoking.

Labels: cigarette smoking, FEV1, jonathan foulds, lung function, smoking cessation

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Marlboro Snus Isn’t Really Snus

In some prior posts I’ve talked about the type of smokeless snuff tobacco that is very popular in Sweden, called “snus”. This product has captured considerable attention because in that country more men now use it than smoke cigarettes, and because it is lower in toxins and carcinogens than other forms of smokeless tobacco (such that it doesn’t cause oral or lung cancer, but probably does cause pancreatic cancer, though less than smoking). It has also captured the attention of multinational tobacco companies, and is currently being test marketed in many countries, including the US.

Swedish snus is a moist snuff product (50% water) that delivers a comparable amount of nicotine to a cigarette. However, it appears that most of the versions being test-marketed in the US have very low nicotine delivery. Marlboro snus, in particular, appears to be a quite different product from Swedish snus. It is relatively dry (12% water), has a low pH, and therefore delivers an amount of nicotine to the blood that is less than 20% of that delivered by leading brands of Swedish snus (e.g. General) or US smokeless (e.g. Copenhagen) or cigarettes. On analyzing some of the data on Marlboro snus, and trying to understand why Philip Morris have produced a product with such low nicotine delivery, Dr Helena Furberg (from University of North Carolina) and I suspect that the product may be designed to fail. If you have tried any of the new smokeless tobacco products being test-marketed in the US or other countries (e.g Taboka, Camel snus, Marlboro snus, Ariva, Exalt, Skoal Dry, Revel, etc) I’d be interested to hear what you thought of them and their marketing.

If you are thinking of switching from smoking to a safer form of nicotine delivery, then far better to miss out the tobacco products altogether and move onto a product with reasonable nicotine delivery but no carcinogens, like 4mg nicotine gum. Some of the NRT products are now being sold in much better flavors than the original. They are not intended for long-term use, but if you feel you want to keep taking nicotine in a form that won’t kill you, this is a better choice than some unregulated tobacco product with unknown ingredients and nicotine delivery.

If you’d like to read the full article on Marlboro snus, with links to other data, it can be accessed at:
http://www.harmreductionjournal.com/content/5/1/9

Labels: jonathan foulds, marlboro snus, nicotine regulation reduction smoking smokeless, tobacco

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