Study reveals the genetic mutations suffered by smokers 
who go on to develop lung cancer
One genetic mutation occurs on average for every 15 cigarettes that a typical lung-cancer patient smokes, according to a study that has identified for the first time all of the mutations acquired during the lifetime of a cancer patient.
Scientists have completed a full genetic analysis of the genomes of cancer patients, and hope the information will lead to a fundamental understanding of the causes of cancer – and possibly drugs and treatments – by identifying the mutations that turn a healthy cell into a cancerous tumour cell.
They studied a lung-cancer victim who had built up about 23,000 DNA mutations in his lung cells that were linked with exposure to the toxins found in cigarette smoke and had accumulated over his lifetime.
They also looked at a patient with malignant melanoma, the most dangerous form of skin cancer, who had acquired 30,000 specific genetic mutations known to be associated with exposure to sunlight.
Scientists believe this new insight into the genetics of cancer will eventually lead to new drugs and tailor-made treatments that target the specific changes to the gene that help to trigger the disease, as well as new techniques for identifying secondary cancers that have evaded treatment in other parts of the body.
"For the first time, we have a comprehensive map of all mutations in a cancer cell," said Dr Peter Campbell of the Wellcome Trust Sanger Institute in Cambridge, which led the Cancer Genome project to decipher the entire DNA sequence of tumour cells in order to identify the mutations.
"The profile of mutations we observed [in the lung-cancer patient] is exactly that expected from tobacco, suggesting that the majority of the 23,000 we found are caused by the cocktail of chemicals found in cigarettes. On the basis of average estimates, we can say that one mutation is fixed in the genome for every 15 cigarettes smoked," Dr Campbell said.
The study, published in the journal Nature, involved the sequencing of the entire genome of a lung-cancer cell 60 times in order to be sure that all of the smallest mutations were identified. The scientists then compared the genome sequence with that of a healthy cell taken from the same patient.
A similar procedure was performed on the cells of a patient with skin cancer, which is how the researchers were able to show that the malignant skin cells contained changes that resulted from exposure to ultraviolet light, said Professor Mike Stratton at the Sanger Institute.
"These are the two main cancers in the developed world for which we know the primary exposure. For lung cancer it is cigarette smoke, and for malignant melanoma it is exposure to sunlight," Professor Stratton said.
"With these genome sequences, we have been able to explore deep into the past of each tumour, uncovering with remarkable clarity the imprints of these environmental mutagens [mutation-causing agents] on DNA, which occurred years before the tumour became apparent," he said.
Friday, December 18, 2009
15 cigarettes: all it takes to harm genes
-Steve Connor
Revolutionary case against tobacco use in Nigeria
-Alexander Chiejina
…Tobacco control bill yet to be passed by National Assembly 
Without a doubt, the health, economic, social, and environmental consequences of tobacco use in Nigeria and the continent are enormous.
Little wonder the World Health Organisation (WHO) recently revealed that African countries are experiencing a 4.3 percent annual increase in the rate of tobacco consumption. This has resulted in an upsurge of lung cancer and related cases which are now prevalent in the society.
It was against this background that experts, at a recent training for health reporters on cancer reporting organised by Journalists Advocacy on Tobacco and Health held recently at Ogba, Lagos urged that the trend should be checked.
Speaking at the event, Akinbode Oluwafemi, programme manager, Environmental Rights Action/Friends of the Earth (FoEN), noted that tobacco smoking is responsible for more than 85 percent of lung cancers. This, he explained, is because smoking-related cancer accounts for 30 percent of cancer-related deaths, adding that renowned journalists in the country like Steve Kadiri, Yinka Craig, Momoh Kubanji, Tina Onwudinwe and Beko Ransome Kuti lost their lives due to the health hazards associated with the consumption of cigarettes.
“Research findings have it that there are about 599 approved additives in a stick of cigarette. However, cigarette smoke has been proven to contain over 4000 toxic and cancer causing chemicals; carbon monoxide, nitrogen oxides, hydrogen cyanide, ammonia, to name but a few,” Oluwafemi disclosed. According to him, cigarette advertising, promotion and sponsorship such as ‘Welcome to London, cool feeling’ have made cigarette smoking appealing to a lot of youths, without some of these tobacco companies apprising the public of dangers associated with smoking.
Lending his view, Tosin Orogun, programme manager, Communications and IT, Africa Tobacco Control Regional Initiative (ATCRI), declared that the rise in cigarette smoking in the society is traceable to tobacco companies which increasingly target the developing world as barriers rise and smoking rates fall in more mature markets. “What we (ATCRI) have been trying to do is to facilitate the adoption, implementation and enforcement of effective in-country tobacco control policies, legislation and programs in Nigeria and across the continent,”
Orogun revealed. Already, a 2009 report on the implementation of smoke-free environments aimed at combating Global Tobacco Epidemic shows that five more countries (Djibouti, Egypt, Islamic Republic of Iran, Malaysia and Mauritius) meet the best practices for health warnings on cigarette packages. Three other countries (Israel, Romania and the United Arab Emirates), meanwhile, offer comprehensive help in the drive to eradicate tobacco consumption. In the same vein, only Panama has joined the small group of countries that ban all forms of tobacco advertising, promotion and sponsorship, even as more than 90 percent of people lack protection from tobacco industry marketing. Six more countries (Czech Republic, Estonia, Fiji, Finland, the Netherlands and Seychelles) have levied tobacco taxes higher than 75 percent of retail price.
Lastly, of the world’s 100 most populous cities, 22 are smoke-free. Sadly, though, reports from the recently concluded media summit hosted by the American Cancer Society ahead of the AORTIC cancer in Africa, stated that 55 percent of school students are not aware that secondhand smoke is harmful to health, and only 1 percent of Nigeria’s population are protected by strong smoke-free laws. This lays bare the fact that if nothing is done to hastily check public smoking in the country, the rising figures of cancer and other non-communicable diseases may remain.
The bill to ban cigarette smoking in public places which had its public hearing before the National Assembly 19 July this year should quickly be passed into law. A part of the bill which seeks to protect people from secondhand smoke, raise taxes on tobacco, enforce a level of ban on tobacco advertising, promotion and sponsorship would in the long run, save Nigerians from self- inducing cancer types.
Without a doubt, the health, economic, social, and environmental consequences of tobacco use in Nigeria and the continent are enormous.Little wonder the World Health Organisation (WHO) recently revealed that African countries are experiencing a 4.3 percent annual increase in the rate of tobacco consumption. This has resulted in an upsurge of lung cancer and related cases which are now prevalent in the society.
It was against this background that experts, at a recent training for health reporters on cancer reporting organised by Journalists Advocacy on Tobacco and Health held recently at Ogba, Lagos urged that the trend should be checked.
Speaking at the event, Akinbode Oluwafemi, programme manager, Environmental Rights Action/Friends of the Earth (FoEN), noted that tobacco smoking is responsible for more than 85 percent of lung cancers. This, he explained, is because smoking-related cancer accounts for 30 percent of cancer-related deaths, adding that renowned journalists in the country like Steve Kadiri, Yinka Craig, Momoh Kubanji, Tina Onwudinwe and Beko Ransome Kuti lost their lives due to the health hazards associated with the consumption of cigarettes.
“Research findings have it that there are about 599 approved additives in a stick of cigarette. However, cigarette smoke has been proven to contain over 4000 toxic and cancer causing chemicals; carbon monoxide, nitrogen oxides, hydrogen cyanide, ammonia, to name but a few,” Oluwafemi disclosed. According to him, cigarette advertising, promotion and sponsorship such as ‘Welcome to London, cool feeling’ have made cigarette smoking appealing to a lot of youths, without some of these tobacco companies apprising the public of dangers associated with smoking.
Lending his view, Tosin Orogun, programme manager, Communications and IT, Africa Tobacco Control Regional Initiative (ATCRI), declared that the rise in cigarette smoking in the society is traceable to tobacco companies which increasingly target the developing world as barriers rise and smoking rates fall in more mature markets. “What we (ATCRI) have been trying to do is to facilitate the adoption, implementation and enforcement of effective in-country tobacco control policies, legislation and programs in Nigeria and across the continent,”
Orogun revealed. Already, a 2009 report on the implementation of smoke-free environments aimed at combating Global Tobacco Epidemic shows that five more countries (Djibouti, Egypt, Islamic Republic of Iran, Malaysia and Mauritius) meet the best practices for health warnings on cigarette packages. Three other countries (Israel, Romania and the United Arab Emirates), meanwhile, offer comprehensive help in the drive to eradicate tobacco consumption. In the same vein, only Panama has joined the small group of countries that ban all forms of tobacco advertising, promotion and sponsorship, even as more than 90 percent of people lack protection from tobacco industry marketing. Six more countries (Czech Republic, Estonia, Fiji, Finland, the Netherlands and Seychelles) have levied tobacco taxes higher than 75 percent of retail price.
Lastly, of the world’s 100 most populous cities, 22 are smoke-free. Sadly, though, reports from the recently concluded media summit hosted by the American Cancer Society ahead of the AORTIC cancer in Africa, stated that 55 percent of school students are not aware that secondhand smoke is harmful to health, and only 1 percent of Nigeria’s population are protected by strong smoke-free laws. This lays bare the fact that if nothing is done to hastily check public smoking in the country, the rising figures of cancer and other non-communicable diseases may remain.
The bill to ban cigarette smoking in public places which had its public hearing before the National Assembly 19 July this year should quickly be passed into law. A part of the bill which seeks to protect people from secondhand smoke, raise taxes on tobacco, enforce a level of ban on tobacco advertising, promotion and sponsorship would in the long run, save Nigerians from self- inducing cancer types.
Wednesday, December 16, 2009
Tuesday, December 15, 2009
Wednesday, December 9, 2009
Smoking cessation offers measurable benefits for asthmatic patients
The Medical News
Asthmatic smokers may be able to reverse some of the damage to their lungs that exacerbates asthmatic symptoms just by putting down their cigarettes, according to research out of the University of Groningen in the Netherlands.
SOURCE
Airway Epithelial Changes in Smoking but not in Ex-Smoking Asthmatics
Am J Respir Crit Care Med. 2009 Oct 1. [Epub ahead of print]
Broekema M, Ten Hacken NH, Volbeda F, Lodewijk ME, Hylkema MN, Postma DS, Timens W.
Asthmatic smokers may be able to reverse some of the damage to their lungs that exacerbates asthmatic symptoms just by putting down their cigarettes, according to research out of the University of Groningen in the Netherlands.The research is published in the December 15 issue of the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.
"We found that exposure to cigarette smoke appears to increase the thickness of the epithelium, or lining, of the airways in the lung. This may be the underlying cause of the fact that smoking asthma patients experience more asthma symptoms, such as shortness of breath and phlegm production, compared to non-smoking asthma patients," said Martine Broekema, Ph.D., the lead author of the study.
Dr. Broekema and colleagues examined patients with asthma who were assessed each for the severity of their asthma and allergy, given questionnaires to determine the extent of their smoke-induced symptoms, and then underwent bronchial biopsies. Of the total of 147 patients, 66 never smoked, 46 were ex-smokers and 35 were current smokers.In addition to the changes in the epithelial thickness, Dr. Broekema found distinct differences between the current smokers and the ex- and non-smokers.
"In addition to the epithelial thickening, we found that cigarette smoke negatively affects levels of exhaled nitric oxide, making it an unreliable indicator of asthma severity in smokers," she said.
Current smokers also had more mucous-producing goblet cells in their epithelium and, the epithelial cell layer contained more mucus protein overall, when compared to never-smoking asthmatics. "These pathological findings were associated with the severity of phlegm production reported by the asthma patients, suggesting a causal relationship between the two. Smoking asthmatics also showed a distinct inflammatory profile in their lungs compared to never-smoking asthmatics, with a lower number of eosinophils and higher number of mast cells," said Dr. Broekema. "Furthermore, our data suggest that smoking cessation can reverse the thickening of the lining of the airways.
"To determine the role of exposure length on asthmatic lungs, the scientists divided the ex-smokers into two groups: those with fewer than the median 3.4 pack-year exposure and those with more than 3.4 pack-years.Interestingly, while they expected to find evidence of a dose-response effect between smoking and epithelial remodeling, no such association was apparent between the number of pack-years or duration of smoking cessation and epithelial remodeling.
"To our surprise, these two sub-groups of ex-smokers showed no difference in any outcome measure. These sub-analyses indicate that the amount of smoke exposure in the past does not influence our outcome measures," said Dr. Broekema. "This study shows again how important smoking cessation is for pulmonary health, and this appears to be especially true for asthmatic patients. The good news is that quitting appears to have a measurable benefit in these individuals."
SOURCE
Airway Epithelial Changes in Smoking but not in Ex-Smoking Asthmatics
Am J Respir Crit Care Med. 2009 Oct 1. [Epub ahead of print]
Broekema M, Ten Hacken NH, Volbeda F, Lodewijk ME, Hylkema MN, Postma DS, Timens W.
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