44% of cancer patients continue smoking after diagnosis

Nearly half of cancer patients who smoked when they received their diagnosis continued smoking afterward, according to an analysis by Samsung Seoul Hospital researchers.

The study examined 46,834 smokers diagnosed with cancer using National Health Insurance Service data from 2015 to 2022. It found that 17,418 people, or 37.2%, continued smoking conventional cigarettes, while 3,507, or 7.5%, switched to e-cigarettes. In total, 44.7% still smoked after their diagnosis.

Among those who switched to e-cigarettes, 2,252 people, or 64.2%, continued smoking both conventional and electronic cigarettes. By comparison, 25,909 patients, or 55.3%, quit smoking completely.

The research team from Samsung Seoul Hospital’s Cancer Hospital analyzed the patients’ outcomes over a median period of 4.2 years. The researchers said those who quit after their cancer diagnosis had a 36% lower risk of cardiovascular disease, including myocardial infarction, than patients who continued smoking. The analysis accounted for factors including age, sex, income, cancer type, treatment method and smoking levels before diagnosis.