Adherence to general medical checkup and cancer screening guidelines according to self-reported smoking status: Korea National Health and Nutrition Examination Survey (KNHANES) 2010-2012

Objectives The National Lung Screening Trial (NLST) revealed that low-dose computed tomography (LDCT) screening could reduce lung cancer mortality in heavy smokers. Lung screening with LDCT was implemented in July 2019 as part of the National Cancer Screening Program in Korea for heavy smokers who meet NLST criteria [smokers aged 55-74 years with 30 pack-years (PY) or more, excluding former smokers with more than 15 years since smoking cessation]. This study evaluated NLST-eligible heavy smokers' adherence to general medical checkup and cancer screening guidelines. Methods Using the Korea National Health and Nutrition Examination Survey (KNHANES) from 2010 to 2012, we compared adherence of Korean adults (55-74 years, n = 5,480) to general medical checkup and cancer (gastric, colorectal, breast, and cervical) screening guidelines according to self-reported smoking status. Smoking and PY data were available, but no data indicating when former smokers ceased smoking were available. Accordingly, smoking status was only classified as NLST (smokers with a history >= 30 PY) and non-NLST. Individuals who met NLST criteria were subdivided into current (NLST-current) and former smokers (NLST-former). Multivariable logistic regression was used to evaluate adherence to screening recommendations as a function of the study group (NLST-current, NLST-former, non-NLST) using possible covariates (sociodemographic factors, health-related behaviors, comorbidities, and self-reported health status). Results Weighted prevalence of NLST-current was 9.7%, of NLST-former was 9.6%, and of non-NLST was 80.7%. Overall screening rates were 70.7% (medical checkup), 59.1% (stomach cancer), 58.1% (colorectal cancer), 59.1% (breast cancer), and 48.9% (cervical cancer). Adherence to colorectal cancer screening and medical checkup was lower in NLST-current than non-NLST (AOR 0.59; 95% CI 0.44-0.78 for colorectal cancer; AOR 0.70; 95% CI 0.52-0.95 for medical checkup). Screening practices for other cancers were not different. Conclusions Current heavy smokers meeting NLST criteria were less likely to have colorectal cancer screening or general medical checkup. Understanding the screening practices of this target population might enable the development of more effective plans to implement lung screening and improve screening compliance for other cancers.