Upcoming Trials Seek to Determine Cancer-Related Health Effects of E-Cigarettes

A recent national consumer survey noted that 44 percent of Americans under the age of 35 consider electronic cigarettes, also known as e-cigarettes or e-cigs, to be less harmful to the lungs than traditional cigarettes. Two upcoming clinical studies at The Ohio State University Comprehensive Cancer Center — Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (The OSUCCC – James) aim to discover the health effects of using e-cigarettes and are currently still recruiting healthy volunteers.

“We have no idea where in the spectrum these are, in terms of safety,” Peter Shields, M.D., said in a press release. “Are they like cigarettes, or nothing like cigarettes? Do they affect people the same if they’ve never smoked, or a lot worse? We need to figure this out.”

Even the question of whether or not e-cigs contain toxic elements isn’t so simple. Shields, a thoracic oncologist, cancer control researcher and deputy director of The OSUCCC — James explained in an interview with CURE, “It’s not only whether there’s something ‘bad’ that’s there, but how much.”

An e-cigarette contains carriers for nicotine — propylene-glycol and glycerin – and flavoring. The carriers are considered safe when coming in contact with skin or when eaten. However, as Shields added, “We don’t know if they’re safe when inhaled. The lungs don’t have the same barriers as your skin and your stomach, to prevent from being harmed.”

There are also concerns about breakdown products, which depend upon how much electricity is applied and how heated the e-cig gets. Those breakdown products, according to Shields, are acrolein, acetaldehyde, and, “depending on how high the electricity goes, you could get something like formaldehyde.” Acrolein and acetaldehyde are not considered human carcinogens, but they are irritants. “Irritation is part of a cancer pathway, but those chemicals are just not strong enough by themselves to cause cancer in animals, at least.”

Formaldehyde, though, is, as Shields explained, “considered by some authorities and regulatory agencies as a human carcinogen for leukemia.” It’s uncertain if the levels of formaldehyde that an e-cig can produce are enough to be of concern.

Currently, most studies about these substances are done in laboratories, as machine studies. “They do their best to replicate how people smoke e-cigs, but that's really hard,” Shields said. At The OSUCCC — James, researchers are conducting human studies to better determine the health effects of e-cigs.

The first study will compare the lung tissue of non-smokers, e-cig users and traditional cigarette smokers. To directly assess the impact of tobacco and e-cigs on the lungs, researchers will be performing bronchoscopies on the volunteers. This medical procedure allows researchers to view the airways and collect a small sample of lung cells from fluid in the lungs.

The non-smoker volunteers in this study will also be asked to use an e-cig that uses no nicotine or flavor for one month before undergoing another bronchoscopy.

From the results of those studies, Shields said he hopes to see the levels of differences and determine “whether we need to do a bigger study to get a better handle on what is the comparison between those three groups.”

The second study will consist of two phases, a baseline phase and an eight-week clinical trial. Participants will complete questionnaires and provide urine and mouth cell samples. From there, participants will be randomized to one of two groups: an arm that will switch to e-cigs or an arm that switches to medicinal nicotine via gum or lozenges for eight weeks.

“This study,” Shields said, “is aimed at identifying how different methods of using tobacco impacts the exposures that happen when smoking the product or using e-cigs.”

Researchers at the OSUCCC — James hope that these trials will provide data to help science “catch up with the consumer market,” as Shields put it, “and determine whether e-cigs truly are a safer option than traditional cigarettes.

“The field is moving fastand we just don't know. Some of these questions, maybe we'll never answer,” Said Shields.