E-Cigarette Use Gains Among Cancer Patients

Electronic cigarette use among cancer patients and survivors have increased in recent years, while conventional cigarette smoking rates have remained stable, a new study finds.

When the researchers analyzed data from the CDC's National Health Interview Survey (NHIS), which has tracked the nation's health for more than 6 decades, they found that roughly one in 10 survey respondents reporting a cancer diagnosis in surveys conducted from 2014 to 2017 had used e-cigarettes.

Cancer patients and former patients who were younger than age 50 were most likely to have used e-cigarettes, and use was highest in the later survey year of 2016-2017.

As shown in the study online in JAMA Oncology, the trend toward increasing e-cigarette use among the cohort with a cancer diagnosis appeared to be driven by former smokers, especially those younger than 50.

In a telephone interview, the study's lead researcher, Nina Sanford, MD, of the University of Texas Southwestern Medical Center in Dallas, said the NHIS data also raises concerns that e-cigarettes are not helping smokers kick the cigarette habit: "We saw a significant increase in e-cigarette use, especially among younger cancer patients, but there was no corresponding decline in smoking rates," she said.

The NHIS began asking participants about their e-cigarette use in 2014. In the new study, Sanford and colleagues analyzed survey data from 2014 to 2017 and used multiple logistic regression to define the adjusted odds ratio (AOR) and associated confidence intervals for the odds of using e-cigarettes, with year of survey response (2014-2015 vs 2016-2017) as the primary independent variable.

The analysis included 13,274 survey respondents who self-reported a cancer diagnosis. The median age was 68 (range 18-85), and 1,259 (9.5%) had used e-cigarettes.

"Although the rates of conventional smoking remained stable from 2014 to 2017 (50.7% to 51.9%, P=0.36), the prevalence of e-cigarette use increased from 8.5% to 10.7% (P=0.01), and later survey year (2016-2017) was associated with increased odds of e-cigarette use (AOR,1.26; 95%CI, 1.01-1.57)," the researchers wrote.

Among the other main findings:

• Age younger than 50 was also associated with higher odds of e-cigarette use (AOR, 3.79; 95% CI, 2.86-5.03)
• The positive association between later survey year (2016-2017) and e-cigarette use was seen only in participants younger than 50 (AOR, 1.71; 95% CI, 1.17-2.51) and not in those 50 or older (AOR, 1.05; 95% CI,0.82-1.35) (P=0.02 for age×year interaction)
• From 2014 to 2017, the prevalence of e-cigarette use among participants younger than 50 increased from 22.8% to 26.8% (P=0.01), compared with 6.0% to 8.0% (P=0.20) among participants who were age 50 or older

The prevalence of e-cigarette use among current and never smokers remained stable throughout the study period, but e-cigarette use among former smokers increased from 5.8% to 8.3% from 2014 to 2017.

Study limitations cited by the researchers included the self-reported nature of the data, the fact that most of the survey respondents included in the analysis were white, and the inability "to comment on whether e-cigarette use affected quantity of conventional smoking."

Sanford told MedPage Today that it is especially concerning that younger cancer patients and survivors are more likely to use e-cigarettes because there is, as yet, no long-term safety information of the relatively new tobacco products.

"We don't have the long-term data to tell us if e-cigarettes are carcinogenic and, if they are, to what degree," she said. "The jury is still out on their safety, especially for younger cancer patients, who potentially have longer lifespans."