Experts Highlight Inroads to Preventing Cancer

(HealthDay News) -- Scientists looking at everyday factors that influence cancer risk are finding important new clues that could affect cancer prevention strategies.

"Many of us believe that prevention is better than trying to identify drugs for people after they get cancer," said Dr. Peter Shields, deputy director of the Lombardi Comprehensive Cancer Center and interim chairman of the Department of Medicine at Georgetown University Medical Center in Washington, D.C. "As we understand risk factors better, it may be possible to personalize cancer prevention."

Shields moderated a Monday teleconference highlighting cancer prevention-related findings that are being presented at the annual meeting of the American Association for Cancer Research, in Denver.

One study found that two common gene variants do not protect individuals from the ill effects of smoking.

In the study, smoking boosted the odds for the two most common types of colorectal polyps: adenomas and hyperplastic polyps, although the association was stronger in the latter.

People who had smoked a pack of cigarettes a day for a year had a 68 percent increased risk for adenomas but a 238 percent increased risk for hyperplastic polyps. Those still smoking had the same risk for adenomas as former smokers but a more than threefold increased risk for the second type of polyp.

Polyps can be precursors to colon cancer, but if they're detected early, the disease can often be prevented.

There was also a slight though not statistically significant risk from "charred" (well done) meat.

"Susceptibility to smoking did not vary by this gene, and everyone needs to be concerned [about the risk of smoking]," said Andrea N. Burnett-Hartman, a doctoral student at the Fred Hutchinson Cancer Research Center in Seattle.

"This gene is not going to protect you from the carcinogenic effects of smoking, at least in colorectal tissue," she said. In terms of meat consumption, she added that "everything in moderation" remains a good rule.

Another study found that specific genetic variations in the cox-1 and cox-2 genes indicate different risks for colorectal cancer. This might help determine who would benefit from the cancer-prevention benefits of nonsteroidal anti-inflammatory drugs (NSAIDs).

Although NSAIDs, including aspirin and cox-2 inhibitors, have been shown to reduce the risk of colorectal cancer, that benefit may be nullified by an increased risk of heart disease seen in some cox-2 inhibitors such as Vioxx, which was removed from the market.

Other findings being presented at the society's meeting include:

• A tool that looks simultaneously at several genetic variants and family history might more accurately predict who is at risk for prostate cancer and who could benefit from more aggressive prevention efforts. Men who had at least 15 of the gene variants included in the tool were found to have a 34 percent increased risk of developing prostate cancer in a 20-year span, or 45 percent increased risk if they had a family history of the disease. But without the combination of genetic information, their risk would have been estimated at only 13 percent.
• Rats born to mothers who had been given folic acid supplementation during and after pregnancy were found to have experienced changes in DNA methylation in both the liver and the colon. DNA methylation is a process whereby genes can be turned off or on. Folic acid is recommended before and during pregnancy to prevent neural tube defects in babies. Folic acid intake in North America has soared since these recommendations were implemented in 1998.
• Abnormal collections of cells were found in the blood of 38 percent of people with chronic lymphocytic leukemia (CLL) as early as 10 years before their diagnosis -- something that could be a clue in the so-far fruitless search for causes of the disease. "Apparently, these cells are cranking out proteins years before people get CLL," said Dr. Neil Caporaso, a section chief at the U.S. National Cancer Institute. "We can try to understand what causes people to get these abnormalities and, more importantly, what causes somebody to progress from having relatively benign protein abnormalities to developing leukemia. We can search for environmental agents and genes that could cause this next step."

More information
The American Cancer Society has more on preventing cancer.

A Creamy Treat for "Lungevity"

Step one for preventing lung cancer: say no to tobacco. Step two: have a tablespoon of . . . Read more.

Nicotine Replacement May Help Smokers Quit Gradually

(HealthDay News) -- For smokers who want to cut down on the number of cigarettes they smoke, using nicotine replacement therapy not only helps them smoke less but makes it twice as likely that they will quit altogether, British researchers report.

Although using nicotine replacement therapy -- such as gum, inhalers, patches and lozenges -- as a way to reduce smoking is approved in Britain and other countries, it remains unapproved and controversial in the United States. Some think it sends the wrong message -- that cutting down on smoking is OK. Others think that because tobacco companies make other nicotine delivery devices, this approach is merely a boon to the tobacco industry.

"We looked at papers that took people who said, 'I don't want to stop smoking, but I am prepared to reduce my smoking,' " said lead researcher Dr. Paul Aveyard, from the School of Health and Population Sciences at the University of Birmingham. They were given either a nicotine replacement product or a placebo, "and twice as many in the active treatment groups quit smoking compared with the placebo side," he said.

The results are similar to studies on the use of nicotine replacement therapy among people who said they wanted to quit.

In addition, Aveyard said, there were no serious adverse effects from the use of nicotine replacement while people continued to smoke.

The findings were published online April 3 in BMJ.

For the study, Aveyard's team reviewed seven studies that compared the use of nicotine gum or inhalators with placebos to see which was more effective in gradually getting smokers to quit. The studies included a total of 2,767 people.

Over six to 18 months, 6.75 percent of those using nicotine replacement stopped smoking for six months -- double the proportion of those using placebos. The researchers said it meant that 3 percent of smokers quit who otherwise would not have.

Participants in the studies who used nicotine replacement also received regular behavioral support and monitoring, and the researchers said that this support may have been as important as the nicotine replacement itself.

Aveyard said that use of nicotine replacement would allow treatment of many more smokers than the small number who say they want to quit. "It potentially opens the door to treat almost all smokers with treatments that were formally reserved for people who are wanting to quit right now," he said.

Because most nicotine replacement drugs are available over-the-counter but are not approved in the United States for smoking reduction, Aveyard suggests that people who want to try this approach should first consult with their doctor.

Dr. Norman H. Edelman, chief medical officer of the American Lung Association, predicted that the topic is going to be widely discussed in the United States.

"In Britain, they are a little bit ahead of us," Edelman said. "Right now, the FDA approval for nicotine replacement therapy is as an aid to cessation. The next issue is whether we should use nicotine therapy to reduce smoking without worrying about whether people quit or not."

The American Lung Association says that it should be used to help people quit smoking, but the group has "not adopted the idea of using nicotine replacement therapy for risk reduction," Edelman said.

And whether the Food and Drug Administration will approve its use to cut down on smoking is unclear, he said.

"It's a hot potato topic," Edelman said. "Cigarette companies are manufacturing nicotine delivery devices of all kinds, and there is a tendency to be negative about that. Nobody feels kindly disposed to letting tobacco companies make nicotine delivery devices."

And using nicotine replacement to reduce smoking sends the message that you can benefit by just smoking less, and "the American Lung Association is very opposed to that," Edelman said. "We do not support risk reduction by just smoking fewer cigarettes."

In a related article in the Journal of Thoracic Oncology, researchers reported that programs to help people quit smoking are cost-effective even for people with lung cancer.

A research team led by Dr. Christopher Slatore, from the University of Washington in Seattle, found that a smoking cessation program started before lung resection surgery was cost-effective both one and five years after surgery. They based their analysis on length of survival and improvement in the person's quality of life.

Although the results of the study apply only to people eligible for resection, all lung cancer patients should take part in smoking cessation programs, the researchers concluded.

More information
The American Lung Association has more on quitting smoking.

Newly Pregnant Smokers Have a 15-Week Window to Quit

(HealthDay News) -- Pregnant women who quit smoking before the 15th week of pregnancy reduce their risk of premature birth and having small babies to that of nonsmoking women, a new study finds.

It's known that smoking during pregnancy increases the risk of miscarriage, ectopic pregnancy, premature birth, small babies, stillbirth and neonatal death, but no study until now has determined whether stopping smoking in early pregnancy reduces the risks of small babies and premature births, the study authors said.

"Pregnant women who smoke should be encouraged and assisted to become smoke-free early in pregnancy," said lead researcher Dr. Lesley McCowan, an associate professor of obstetrics and gynecology at the University of Auckland in New Zealand.

Women who don't quit smoking by 15 weeks are three times more likely to give birth prematurely and twice as likely to have smaller babies, compared to women who stopped smoking, McCowan said.

The findings were published in the March 27 online issue of BMJ.

For the study, McCowan's team collected data on 2,504 pregnant women. Eighty percent did not smoke, 10 percent had quit smoking and 10 percent were current smokers.

There was no difference in the rate of spontaneous premature birth between women who did not smoke and those who had stopped by week 15 (4 percent vs. 4 percent). The same was true for having smaller babies (10 percent vs. 10 percent), the researchers found.

However, women who continued to smoke had higher rates of spontaneous preterm birth than woman who quit (10 percent vs. 4 percent) and higher rates of smaller babies (17 percent vs. 10 percent).

The study also found that women who stopped smoking weren't more stressed than women who continued to smoke, McCowan noted.

"Health professionals who care for pregnant women need to ask about smoking, advise about the importance of stopping, and, where possible, refer for extra support early in pregnancy to assist women to become smoke-free," she advised.

Dr. Richard Frieder, an associate clinical professor of obstetrics and gynecology at the University of California, Los Angeles David Geffen School of Medicine, said the study authors didn't explain whether this difference in low birth weight and gestational age at delivery actually translates into a measurable difference in newborn health.

"We assume this to be true, but there was only about a half pound difference in birth weight and six days difference in gestational age. These numbers are not very impressive that one would think a big difference in neonatal health would be achieved. Still, we should assume that a half pound and six days more of gestation is better and that we should strive to help women stop smoking," he said.

There are other big issues at play when it comes to babies, women and cigarette smoke, Frieder added.

"Babies that live in 'smoking homes' have a much higher risk of respiratory ailments, such as asthma and pneumonia and SIDS. In addition, women are more susceptible to the cancer-causing effects of cigarette smoke than men. The tobacco industry specifically targets women, despite this well-known fact," he said.

More information
For more on smoking and pregnancy, visit the American Lung Association.

Secondhand Smoke Raises Stroke Risk for Spouses

(HealthDay News) -- Nonsmokers who are married to smokers run a significantly higher risk for experiencing a stroke, a new study suggests.

Researchers also found that ex-smokers married to men and women who still smoke carry an even greater risk for stroke. However, nonsmoking spouses of former smokers do not appear to bear any higher risk for stroke than those married to someone who had never smoked.

"This adds to the growing evidence that secondhand smoke is bad for you, and I hope that it will help people who want to stop smoking to know that it will probably be good for their spouse's health, too," said Maria Glymour, an assistant professor of society, human development and health at the Harvard School of Public Health in Boston. Glymour is also a health and society scholar in the department of epidemiology at Columbia University in New York City.

She and her team were expected to publish the findings in the September issue of the American Journal of Preventive Medicine.

Glymour pointed out that hers is one of the few studies to specifically focus on the potential link between secondhand smoke and stroke risk. She further noted that indications that the association is real and strong stem from a larger National Institute on Aging research effort that tracked a wide range of social factors and their relationship to stroke risk.

In that study, all 16,000-plus participants were 50 and older and married. All were categorized according to smoking habits, and observed for stroke incidence over an average of about nine years between 1992 and 2006.

Nonsmokers married to a current smoker were found to have a 42 percent increased risk for stroke, compared with those married to spouses who had never smoked. Similarly compared, ex-smokers married to a current smoker had a 72 percent increased risk for stroke.

As for those married to ex-smokers, Glymour and her team only observed that the former smokers had kicked their habit at some point one to 50 years before the start of the study. They could not pinpoint exactly how much time would need to elapse after a smoking spouse quits before their husband or wife's stroke risk fully dissipated.

"But we think the risk to the spouse probably starts to decline right away," Glymour noted. "And that would be consistent with what we already know about stroke and active smoking, which is that if you stop smoking your own health risks decline quickly."

Thomas J. Glynn, director of cancer science and trends at the American Cancer Society, said that he found Glymour's analysis to be "very reasonable."

"I agree that one might expect a fairly steep drop-off in stroke risk for the spouse once the smoking partner quits," he said. "We know, for example, that although it takes about 15 years of not smoking to halve your risk for lung cancer, with heart disease it may take not much more than one to two years of cessation to cut back one's own risk to basically that of a nonsmoker, depending on how long you had been smoking. So, this conclusion makes sense."

"And, in general, I would say that this study provides further valuable evidence of the general dangers of secondhand smoke, and, in particular, the great and often over-looked danger of heart disease, he said. And, of course, it emphasizes the need for anyone who smokes to stop smoking, and at a minimum to establish smoke-free zones in the home, or not smoke in the home at all."

More information
For more about secondhand smoke and health risks, visit the American Lung Association.