Men worry about prostate cancer…women worry about breast cancer…everybody worries about colon cancer, skin cancer and brain cancer. But there’s another cancer that claims more Americans’ lives than those five other types combined. It’s lung cancer, the number-one cancer killer in the country, responsible for more than 157,000 deaths each year.
The good news: Recent advances in prevention and detection are helping in the battle against this fearsome disease. For instance, there’s a new screening tool that can cut the odds of dying from lung cancer by 20%. Is it right for you or for someone you love? For answers to that question and more, we turned to Peter Bach, MD, an epidemiologist and lung cancer specialist at Memorial Sloan-Kettering Cancer Center in New York City.
OVERDUE PREVENTION TACTIC
Not all cases of lung cancer are caused by cigarette smoking, but up to 90% are. The percentage of Americans who smoke has declined significantly over the past few decades, from 42% in 1965 to 19% in 2011…but it’s still way too high.
Public education campaigns and high cigarette taxes do help reduce smoking, but now the FDA is exploring a new tactic—regulating or even banning menthol cigarettes. The reason? Because menthol may make it easier to become addicted to smoking and harder to quit.
Why it has taken the FDA so long to consider regulating menthol is a mystery. Back in 2009, when the FDA banned the candy, clove and fruit flavorings that made cigarettes more palatable to young smokers, it also called for an investigation on the impact of mentholated cigarettes on public health. Two years later, the FDA’s advisory committee concluded that it is “biologically plausible” that adding menthol to cigarettes makes them more addictive, and that removing menthol from cigarettes would improve public health.
Menthol’s allure: The addition of menthol is a trick used by tobacco companies—in fact, the flavoring is added to all cigarettes, not just those not marketed as menthol. Menthol-flavored cigarettes have about 10 times more added menthol than regular cigarettes, but even at the lower levels, the menthol helps mask the harshness of tobacco and the irritation associated with nicotine. Without the added menthol, the harshness and irritation could be turnoffs for new smokers—making them less likely to stick with the dangerous habit.
Menthol works by stimulating the cold receptors on nerve endings in the mouth, nose and skin, creating a cooling sensation. When menthol is added at higher levels, the cooling sensation also is felt in the lungs. At the same time, menthol contains substances that enhance nicotine’s “bite,” a sensation that smokers seem to crave, further reinforcing smoking behavior.
The FDA is considering banning menthol because it lures smokers and keeps them, but other studies suggest that menthol also makes cigarettes more harmful. Last year, Bottom Line reported that smokers of menthol cigarettes had more than twice the risk for stroke as smokers of regular cigarettes (click here to read that report). People who smoke menthol cigarettes also show decreased elasticity and increased stiffness of the carotid arteries (the main arteries feeding the brain) compared with smokers of regular cigarettes. In addition, menthol’s cooling action slows respiration, increasing breath-holding time and, in turn, leading to greater exposure to the cigarette’s toxins. What’s more, the cilia (tiny hairlike structures in the airway that move things along) slow down when exposed to menthol, impairing clearance of toxins from the airway.
Our opinion: It’s way past time for menthol to be banned from cigarettes.
LIFESAVING SCREENING: FOR WHOM?
Lung cancer has one of the lowest five-year survival rates of all cancers mainly because it usually is diagnosed too late to be cured. About 90% of people who get lung cancer die because of it.
Recently, the US Preventive Services Task Force, an independent panel of experts in prevention and evidence-based medicine, sought to update its previous determination against routine lung cancer screening for smokers. The task force reviewed relevant studies, relying most heavily on the National Lung Screening Trial (NLST).
The NLST included more than 53,000 smokers who were randomly assigned to undergo three annual exams with either chest x-rays or low-dose CT scans. Findings: In each of the three rounds of screening, CT exams found more cancers than x-rays. In the first round alone, CT scans identified 270 people with lung cancer, compared with 136 in the x-ray group. CT screening reduced lung cancer deaths by 20%.
Based on these findings, a task force recommendation now in draft form advises annual CT screening for people at high risk—those between the ages of 55 and 79 who have a smoking history of at least 30 pack-years. (A pack-year is an average of one pack per day for one year. So, for example, if you smoked two packs each day for 15 years, you have a 30-pack-year history.) The recommendation applies even to ex-smokers who have quit smoking within the past 15 years. (The NLST did not look at ex-smokers who quit more than 15 years ago.)
If you fall in to the high-risk category, should you go get a CT scan? Probably—but there are several factors to consider first, Dr. Bach said, because the benefits to you may not be quite as great as the NLST findings suggest. The NLST was conducted at 33 academic medical centers around the country, all with expertise in diagnosing and managing lung cancer—whereas the same high-quality results may not be found outside of a top-notch academic community. Also, Dr. Bach believes that the task force’s estimate of 20,000 lives saved every year from annual CT screening is overly optimistic. He explained that his institution’s analysis of the data, using different statistical methods, estimates about 4,000 lives saved each year.
Why does it matter whether the true benefits are somewhat less than the NLST suggests? Because CT scans are not without risk. Although low-dose CT exposes you to much less radiation than a standard chest CT, it’s still much higher than the exposure you’d get from a regular chest x-ray. CT scans also may result in false-positive findings or incidental findings (abnormalities that don’t cause harm), both of which can lead to unnecessary invasive testing and anxiety.
Bottom line: If you clearly fall into the high-risk category (age 55 to 79 with a smoking history of at least 30 pack-years and less than 15 years since you quit), you should be aware of the screening option and seriously consider the trade-offs of benefits versus risks. “The most aggressive we should be is to suggest that such patients discuss screening with a doctor who is disinterested—meaning someone who is not the owner of a CT scanner or radiology center,” Dr. Bach said.
Lower-risk people should not be offered screening, in his opinion. “Outside of the high-risk group, the potential danger of radiation vastly exceeds the possible benefits of screening. That’s even more true for women than for men because the radiation also can contribute to breast cancer risk.”
Speaking of women, let’s consider the issue of gender as it relates to lung cancer risk. Lung cancer used to be considered primarily a man’s disease. But several years ago, the pendulum swung in the opposite direction when some studies suggested that female smokers were more susceptible to the harms of cigarettes than male smokers…and that women who had never smoked were more likely to get lung cancer than men who had never smoked.
However, those theories did not hold up in more rigorous studies. Most experts agree, Dr. Bach said, that lung cancer is neither predominantly a man’s disease nor a woman’s disease. Women and men have the same risk of developing lung cancer and dying from it…and it is the leading cause of cancer death for both men and women in the US.
HELP FOR SMOKERS AND EX-SMOKERS
If you smoke or used to smoke, visit these three important Web sites…
- The CDC’s Tips from Former Smokers public service campaign has been instrumental in convincing more than 100,000 smokers to drop their smoking habit.
- Click here to calculate your pack-years—an important number when considering whether CT screening is appropriate for you.
- Memorial Sloan-Kettering Cancer Center, one of the nation’s top cancer hospitals, has developed its own online tool that can help you decide whether you should be screened. The criteria used are slightly different than those developed by the task force—so it will be helpful to discuss the guidelines with your own doctor.