PURPOSE Cigarette smoking is associated not only with increased risk of cancer incidence, but also influences prognosis, and the quality of life of the cancer survivors. Thus, smoking cessation after cancer diagnosis is necessary. However, smoking behavior among Korean cancer-survivors is yet unknown.

MATERIALS AND METHODS We investigated the smoking status of 23770 adults, aged 18 years or older, who participated in the Health Interview Survey of the Korea National Health and Nutrition Examination Survey from 2007 to 2010. Data on the cancer diagnosis and smoking history were obtained from an interview conducted by trained personals. "Cancer-survivor" was defined as anyone who has been diagnosed with cancer by a physician regardless of time duration since diagnosis. Smoking status was classified into "never-smoker", "former-smoker", and "current-smoker". Former-smoker was further divided into "cessation before diagnosis" and "cessation after diagnosis".

RESULTS Overall, 2.1% of Korean adults were cancer-survivors. The smoking rate of Korean cancer-survivors was lower than that of non-cancer controls (7.8±1.3% vs. 26.4±0.4%, p<0.001). However, 53.4% of the cancer-survivors continued to smoke after their cancer diagnosis. In multivariate analysis, male gender [odds ratio (OR), 6.34; 95% confidence interval (CI), 2.62-15.31], middle-aged group (OR, 2.74; 95% CI, 1.12-6.72), the lowest income (OR, 4.10; 95% CI, 1.19-14.15), living with smoking family member(s) (OR, 5.49; 95% CI, 2.42-12.48), and the poor self-perceived health status (OR, 2.78; 95% CI, 1.01-7.71) were independently associated with persistent smoking among Korean cancer-survivors.

CONCLUSION The smoking rate among Korean cancer survivors is low. However, the smoking cessation rate after the cancer diagnosis is also low. This mandates comprehensive and systematic intervention for smoking cessation among cancer-survivors.