Second Hand Smoke

Around one in a hundred deaths worldwide is due to passive smoking, which kills an estimated 600,000 people a year, World Health Organization (WHO) researchers said on Friday.

In the first study to assess the global impact of second-hand smoke, WHO experts found that children are more heavily exposed to second-hand smoke than any other age-group, and around 165,000 of them a year die because of it.

"Two-thirds of these deaths occur in Africa and south Asia," the researchers, led by Annette Pruss-Ustun of the WHO in Geneva, wrote in their study.

Children's exposure to second-hand smoke is most likely to happen at home, and the double blow of infectious diseases and tobacco "seems to be a deadly combination for children in these regions," they said.

Commenting on the findings in the Lancet journal, Heather Wipfli and Jonathan Samet from the University of Southern California said policymakers try to motivate families to stop smoking in the home.

"In some countries, smokefree homes are becoming the norm, but far from universally," they wrote.

The WHO researchers looked at data from 192 countries for their study. To get comprehensive data from all 192, they had to go back to 2004. They used mathematical modeling to estimate deaths and the number of years lost of life in good health.

Worldwide, 40 percent of children, 33 percent of non-smoking men and 35 percent non-smoking women were exposed to second-hand smoke in 2004, they found.

This exposure was estimated to have caused 379,000 deaths from heart disease, 165,000 from lower respiratory infections, 36,900 from asthma and 21,400 from lung cancer.

For the full impact of smoking, these deaths should be added to the estimated 5.1 million deaths a year attributable to active tobacco use, the researchers said.

While deaths due to passive smoking in children were skewed toward poor and middle-income countries, deaths in adults were spread across countries at all income levels.

In Europe's high-income countries, only 71 child deaths occurred, while 35,388 deaths were in adults. Yet in the countries assessed in Africa, an estimated 43,375 deaths due to passive smoking were in children compared with 9,514 in adults.

Pruss-Ustun urged countries to enforce the WHO's Framework Convention on Tobacco Control, which includes higher tobacco taxes, plain packaging and advertising bans, among other steps.

"Policy-makers should bear in mind that enforcing complete smoke-free laws will probably substantially reduce the number of deaths attributable to exposure to second-hand smoke within the first year of its implementation, with accompanying reduction in costs of illness in social and health systems," she wrote.

Only 7.4 percent of the world population currently lives in jurisdictions with comprehensive smoke-free laws, and those laws are not always robustly enforced.

In places where smoke-free rules are adhered to, research shows that exposure to second hand smoke in high-risk places like bars and restaurants can be cut by 90 percent, and in general by 60 percent, the researchers said.

Studies also show such laws help to reduce the number of cigarettes smoked by smokers and lead to higher success rates in those trying to quit.

Great American Smokeout

2010 American Cancer Society Great American Smokeout Facts at a Glance

• This year, the Great American Smokeout will be held November 18.

• Quitting and avoiding tobacco products is one of the most important steps to creating a world with less cancer and more birthdays. It helps Americans stay well by reducing their risk of cancer.

• The Great American Smokeout is designed to motivate and empower smokers with personalized tools, tips, and support to help them quit for good.

• The Society hosted its first Great American Smokeout in 1976 as a way to inspire and encourage smokers to quit for one day.

• Smokeout does more than urge smokers to quit for a single day -- it encourages people to help create a world with less cancer and more birthdays by committing to making a long-term plan to quit for good and/or by supporting laws that help protect communities from tobacco.

• The American Cancer Society and its nonprofit, nonpartisan advocacy affiliate, the American Cancer Society Cancer Action NetworkSM (ACS CAN), have been successful in protecting the public from cigarettes and secondhand smoke:
• Today, nearly 75 percent of the United States population is covered by 100 percent smoke-free workplace and/or restaurant and/or bar laws, despite aggressive efforts by tobacco companies to defeat such laws.*
• Thirty-five states, the District of Columbia, the Northern Mariana Islands, and Puerto Rico now protect nonsmokers by prohibiting smoking in workplaces, and/or restaurants, and/or bars.*
• Forty-seven states and the District of Columbia have increased their cigarette taxes since 2000.*

• In 2007, 39.8 percent (13.4 million) of adult current everyday smokers had stopped smoking for at least one day during the preceding 12 months because they were trying to quit. **

• Tobacco use remains the single largest preventable cause of disease and premature death in the United States.*

New Cancer Drug Shows Promise

An experimental cancer drug is proving effective in treating the lung cancers of some patients whose tumors carry a certain genetic mutation, new studies show.

Because the mutation can be present in other forms of cancer -- including a rare form of sarcoma (cancer of the soft tissue), childhood neuroblastoma (brain tumor), as well as some lymphomas, breast and colon cancers -- researchers say they are hopeful the drug, crizotinib, will prove effective in treating those cancers as well.

In one study, researchers identified 82 patients from among 1,500 patients with non-small-cell lung cancer, the most common type of lung malignancy, whose tumors had a mutation in the anaplastic lymphoma kinase (ALK) gene.

Crizotinib targets the ALK "driver kinase," or protein, blocking its activity and preventing the tumor from growing, explained study co-author Dr. Geoffrey Shapiro, director of the Early Drug Development Center and associate professor of medicine at Dana-Farber Cancer Institute and Harvard Medical School, Boston.

"The cancer cell is actually addicted to the activity of the protein for its growth and survival," Shapiro said. "It's totally dependent on it. The idea is that blocking that protein can kill the cancer cell."

In 46 patients taking crizotinib, the tumor shrunk by more than 30 percent during an average of six months of taking the drug. In 27 patients, crizotinib halted growth of the tumor, while in one patient the tumor disappeared.

The drug also had few side effects, Shapiro said. The most common was mild gastrointestinal symptoms.

"These are very positive results in lung cancer patients who had received other treatments that didn't work or worked only briefly," Shapiro said. "The bottom line is that there was a 72 percent chance the tumor would shrink or remain stable for at least six months."

The study is published in the Oct. 28 issue of the New England Journal of Medicine.

In recent years, researchers have started to think of lung cancer less as a single disease and more as a group of diseases that rely on specific genetic mutations called "driver kinases," or proteins that enable the tumor cells to proliferate.

That has led some researchers to focus on developing drugs that target those specific abnormalities. "Being able to inhibit those kinases and disrupt their signaling is evolving into a very successful approach," Shapiro said.

The good news is that drugs such as crizotinib seem to work well in patients with the mutation, noted Dr. Roman Perez-Soler, chairman of the department of oncology at Montefiore Medical Center and professor of medicine and molecular pharmacology at the Albert Einstein College of Medicine in New York City. But the bad news is that it means that patients who don't have the specific mutation won't be helped.

Only an estimated 2 percent to 7 percent of non-small-cell lung cancers have the ALK mutation, according to the study.

"This is great news for people with this type of tumor," Perez-Soler said. "Researchers have identified a group of patients, unfortunately a small group, who because of a very specific genetic abnormality are extremely sensitive to these targeted treatments and as a result of that can benefit from this drug without toxicity. It's very encouraging."

In a second study in the same journal, crizotinib was effective in a 44-year-old man with inflammatory myofibroblastic tumor, a rare form of sarcoma, which is also driven by the ALK abnormality, said Shapiro, who was senior author of that paper.

Still, there are caveats. Over time, tumors can adapt to such targeted therapy, eventually rendering it ineffective, experts said. In fact, a third study in the same journal identified ways in which lung cancers had already started to mutate and overcome crizotinib.

Moreover, while drugs targeting a specific tumor genotype are promising, there could be so many different genotypes that it would be impractical to come up with drugs targeting all of them, Perez-Soler said. Still other tumors might be fueled by multiple abnormalities.

"Many cancers may be much more complicated," he said. "And every tumor is different. Each one has a number of sophisticated ways to overcome interventions to block growth, and some may be better prepared than others to do that. That is why you see heterogeneity in the response to the drug. There is no such thing as identical twins when we talk about tumors."

Researchers are currently enrolling patients for a larger, Phase III clinical trial of crizotinib, Shapiro said. The study was funded by Pfizer, which is developing crizotinib for clinical application, and by grants from the U.S. National Cancer Institute, among others.

Lung cancer remains one of the most deadly cancers and new treatments are desperately needed, the researchers said. "Advanced lung cancer still remains a very lethal disease," Shapiro said. "It's the biggest cancer killer of both men and women in the U.S. and worldwide, and the unmet clinical need is extreme."