By Yeol Kim, MD, MPH, PhD, and Choon-Taek Lee, MD, PhD
Posted: August 14, 2019
Lung cancer is the leading cause of cancer death worldwide and also in South Korea. Besides avoiding smoking, it is widely accepted that lung cancer screening is possibly the most effective way to reduce lung cancer mortality; however, researchers have only recently provided scientific evidence to support this strategy. In 2011, The National Lung Screening Trial in the United States showed that screening with low-dose computed tomography (CT) targeted to high-risk smokers reduced lung cancer mortality by 20% compared to a control group who received general chest x-rays. More recently, in 2018, a Dutch-Belgian trial (NELSON) also yielded similar results supporting the reduction of mortality.
Based on previous studies, we started the Korean Lung Cancer Screening Project (K-LUCAS) in 2017 to evaluate the feasibility of implementing a population-based lung cancer screening program with the intent to reduce lung cancer mortality rates in South Korea.1 K-LUCAS is the first Asian population–based, nationwide, multicenter prospective lung cancer screening trial. A total of 13,692 people participated in K-LUCAS, which involved 14 hospitals in Korea. The results were promising. The proportion of early-stage lung cancer detection was three times higher in K-LUCAS than the total early-stage lung cancer cases in the national cancer registry.
Ingredients for Success
Lung cancer screening is only recommended for high-risk populations because the harm from participating in lung cancer screening (e.g., exposure to radiation and complications during diagnosis procedures) can be greater than the benefit (e.g., early detection of lung cancer) in low-risk nontarget populations. K-LUCAS also examined the feasibility of selecting appropriate participants based on questionnaires provided by national health screening programs or in smoking cessation clinics. Those questionnaires include questions on current smoking status, smoking history, medical history, and demographics. Questionnaire-based participant selection was evaluated to be an appropriate method in K-LUCAS.
The Korean National Cancer Screening Program (KNCSP) provided a regular cancer screening service for five major cancers (stomach, colon, breast, cervix, and liver), when people come to a certain age. KNCSP will now be expanded to include lung cancer screening.
Another key characteristic of K-LUCAS was the implementation of a network-based diagnosis-supporting system using a computer-aided detection program that aimed to improve nodule detection sensitivity and minimize diagnostic errors. The network-based diagnosis-supporting system was implemented to provide a diagnostic aid for general radiologists to improve quality control and for chest specialists to reduce their reading time. The screening results were standardized by the lung imaging reporting and data system (Lung-RADS) proposed by the American College of Radiology.2 The implementation of the network-based diagnosis-supporting system in K-LUCAS was also effective in keeping the specificity comparatively high while increasing the sensitivity of the screenings.
Finally, K-LUCAS provided mandatory smoking-cessation counseling to all currently smoking participants, as the negative results from lung cancer screening might have provided false reassurance to smokers to continue smoking.
Based on these promising results of K-LUCAS, the government of South Korea has decided to introduce a population-based lung cancer screening program beginning in July 2019.
Details of Implementation
The Korean National Cancer Screening Program (KNCSP) provided a regular cancer screening service for five major cancers (stomach, colon, breast, cervix, and liver), when people come to a certain age. KNCSP will now be expanded to include lung cancer screening. The National Health Insurance Service (NHIS) in Korea supports 90% of the cost of KNCSP as a part of the national social security system.
The national lung cancer program will send invitation letters to screening candidates who are current smokers between the ages of 54 and 74 with at least 30 pack-years of smoking history as reported on the questionnaires submitted in other national health screening programs. The screening interval will be 2 years. Within 2 years, the program plans to expand to ex-smokers with over 30 pack-year exposures. The low-dose CT screening cost per person will be approximately U.S. $100. The examinee will pay only 10% of the cost. Moreover, the lower 50% income group can undergo the lung cancer screening for free.
High-quality screening units throughout the country will be designated for the program based on the facility’s availability of CT with at least 16 channels, certified radiologists with credit for lung nodule evaluation, and physicians who can provide professional counseling for screening results. A web-based program will be available for certified screening units to support the diagnosis and to monitor the quality of the screening.
Challenges and Potential Next Steps
Most people and doctors are delighted to hear about the announcement of lung cancer screening; however, there have been already some disagreements regarding the implementation of this program that must be addressed.
First, many clinics argue that the criteria to qualify as a certified screening center are too strict. Second, concerns have been raised by pulmonologists and thoracic surgeons regarding the potential radiation hazard and morbidity of unnecessary medical or surgical procedures that would follow increased screenings. Finally, it is perceived by the general population and some politicians that screening that targets the population of current heavy smokers with more than 30 pack-years of smoking history is too narrow. Recently, the lung cancer incidence in never-smokers has been increasing rapidly and has become a hot social issue in Korea. Many individuals have insisted that these screenings should be expanded to never-smokers as well. However, there is no evidence of the effectiveness of lung cancer screening for never-smokers, so far. Moreover, the Korean NHIS and the Korean medical arena, in general, do not have the capacity to expand screening to never or light smokers at this time.
Ho Chang, a patient with lung cancer, said, “I personally welcome and am very much pleased with the expansion of the K-LUCAS program as a long-term smoker with more than 30 packs of cigarettes a year. As a result of my long smoking history, I developed lung cancer and have been treated as a patient for more than 5 years and 5 months. If I had been able to benefit from a program like K-LUCAS in the past, I think I would have hastened my decision to stop smoking; as a result, I could have minimized the risk exposure and the chances of getting lung cancer. I hope that this national lung cancer screening program is implemented well and that the number of deaths from lung cancer in Korea can be lowered.”
"As a result of my long smoking history, I developed lung cancer and have been treated as a patient for more than 5 years and 5 months. If I had been able to benefit from a program like K-LUCAS in the past, I think I would have hastened my decision to stop smoking; as a result, I could have minimized the risk exposure and the chances of getting lung cancer." –Ho Chang, Patient with Lung Cancer
As principal investigator of K-LUCAS, I hope that the introduction of this lung cancer screening program can reduce lung cancer mortality in Korea and also provide an opportunity for participants to think about their health seriously, including quitting smoking. ✦
About the Authors: Dr. Kim is a board-certified family physician at the Center for Cancer Prevention and Detection and the Smoking Cessation Clinic, Hospital, National Cancer Center. Dr. Kim is the principal investigator of K-LUCAS. Dr. Lee is with the Division of Pulmonology and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, and the Department of Internal Medicine and Respiratory Center, Seoul National University Bundang Hospital, Seoul, Korea.
1. Lee JH, Lim JT, Kim Y, Kim HY, Goo JM, Lee CT. Development of Protocol for Korean Lung Cancer Screening Project (K-LUCAS) to Evaluate Effectiveness and Feasibility to Implement National Cancer Screening Program. Cancer Res Treat. 2019 Feb 19. [Epub ahead of print].
2. Lee JW, Kim HY, Goo JM, et al. Radiological Report of Pilot Study for the Korean Lung Cancer Screening (K-LUCAS) Project: Feasibility of Implementing Lung Imaging Reporting and Data System. Korean J Radio. 2018;19(4);803-808.