Cancer patients who continue smoking conventional cigarettes after diagnosis face a higher risk of cardiovascular events such as heart attack and stroke, as well as a higher risk of death, than those who quit, according to a new study. Switching to e-cigarettes is better than continuing with conventional cigarettes, researchers said, but falls short of quitting altogether.
Samsung Medical Center said on the 4th that the association was confirmed by a research team including professors Shin Dong-wook and Choi Hye-rim of the Department of Family Medicine, professor Kim Hong-kwan of the Department of Thoracic and Esophageal Surgery, and professor Kang Dan-bee of the Center for Clinical Epidemiology. Using National Health Insurance Service data, the team tracked 46,834 people who were smokers at the time of their cancer diagnosis between 2015 and 2022, following them for a median of 4.2 years.
Smoking is widely regarded as a root cause of disease, because the thousands of chemicals in tobacco smoke affect not only the lungs but also the heart, blood vessels and the body as a whole. Beyond lung cancer, it is known as a major risk factor for cancers of the larynx, esophagus and pancreas, for fatal cardiovascular and cerebrovascular conditions such as heart attack and stroke, and for respiratory diseases including chronic obstructive pulmonary disease (COPD) and asthma.
Of the study participants, 17,418, or 37.2%, kept smoking conventional cigarettes after their cancer diagnosis. More than half, 25,909 people or 55.3%, quit tobacco entirely, while the remaining 3,507, or 7.5%, switched to e-cigarettes. Among those who switched, 2,252 people, or 64.2%, were dual users who also continued smoking conventional cigarettes.
The analysis found that the overall risk of death among those who quit was about 8% lower than among those who kept smoking conventional cigarettes. The gap in the risk of major cardiovascular events, including heart attack and stroke, widened to about 36% between the two groups. The figures were adjusted for age, sex, income, cancer type, treatment method, pre-diagnosis smoking volume and comorbidities.
Those who switched to e-cigarettes had a 16% lower overall risk of death and a 28% lower risk of major cardiovascular events than those who kept smoking conventional cigarettes. That suggests e-cigarettes can serve as an alternative for patients who find it difficult to quit conventional cigarettes even after a cancer diagnosis. Still, a substantial share of those who switch are dual users who also smoke conventional cigarettes, and lung complications can occur, making complete cessation the clearly better option.
"The core of caring for cancer survivors is complete smoking cessation," the research team said. "For patients who cannot quit, switching to e-cigarettes can be carefully considered as a harm-reduction option."
