Current Status of the National Cancer Screening Program in Korea: History, Achievements, and Future Directions

Abstract

Cancer is the leading cause of morbidity and mortality worldwide. To reduce this burden, the Korean government established the National Cancer Screening Program (NCSP) in 1999, initially offering stomach, breast, and cervical cancer screening to Medical Aid Program (MAP) beneficiaries. By 2019, the NCSP had broadened both its eligible population and the range of cancers screened—stomach, liver, cervical, breast, colorectal, and lung—for both MAP recipients and health insurance beneficiaries. Since its inception, participation and adherence to recommended screening have risen steadily, driven by nationwide policy initiatives and expanded access. Over the past 2 decades, the NCSP has played a key role in reducing the incidence of stomach, liver, colorectal, and cervical cancers while increasing detection at precancerous stages, especially for cervical and colorectal cancers. Five-year relative survival rates for major cancers—most notably stomach, colorectal, and breast—have also improved substantially. Accumulated evidence, including cancer detection rates, stage distribution at diagnosis, and mortality reduction, underscores the program’s effectiveness in facilitating early detection and reducing cancer-specific deaths. Notably, Korea’s mortality-to-incidence ratio for major cancers remains well below the Organization for Economic Cooperation and Development average, illustrating the impact of the nation’s comprehensive cancer control strategies. Continued research, surveillance, and refinement of evidence-based screening guidelines will be critical to further enhancing the efficiency and effectiveness of the NCSP.

INTRODUCTION

Cancer is a leading cause of morbidity and mortality worldwide and thus imposes a substantial global health burden [1]. As 30% to 50% of all cancers are preventable, effective prevention and control strategies are essential [2]. Primary prevention measures, such as promoting healthier lifestyles and reducing exposure to carcinogenic infections, are crucial for lowering cancer incidence. However, these strategies cannot completely avert all cases [3]. Consequently, comprehensive cancer control efforts must incorporate early detection through screening to identify malignancies in asymptomatic individuals. Because malignant transformation often involves a prolonged latency period, screening is pivotal for detecting premalignant lesions before symptom onset [4]. Early detection enables timely intervention in the carcinogenic process, delays disease progression, and facilitates curative treatment when feasible and appropriate [4].

Implementation of cancer screening programs reduces cancer-specific mortality. Based on their demonstrated effectiveness, the United States Preventive Services Task Force (USPSTF) concluded that breast, lung, cervical, and colorectal cancer screenings offer considerable net benefits [5-8]. In Korea, a comprehensive free cancer screening program was first implemented in 1999 for stomach, breast, and cervical cancers among Medical Aid Program (MAP) beneficiaries. The program’s scope has gradually expanded to include additional cancer types and eligible populations. As of 2019, it provided screening for screening for 6 major cancers (stomach, liver, colorectal, breast, cervical, and lung) to both MAP and health insurance beneficiaries. Since its inception, the National Cancer Screening Program (NCSP) has been a notable contributor to the steady decline in cancer incidence and mortality in Korea over the past 20 years [9].

History of the National Cancer Screening Program

In Korea, cancer remains a major public health concern, with approximately 280 000 new cases diagnosed and nearly 83 000 cancer-related deaths reported in 2022 [10]. To reduce this burden, the government launched its first comprehensive “10-year Plan for Cancer Control” in 1996, and in 1999, it introduced the NCSP to provide free stomach, breast, and cervical cancer screening to MAP recipient (Table 1). In 2002, the NCSP expanded to include National Health Insurance Service (NHIS) beneficiaries in the lowest 20% income bracket. Since then, eligible individuals have been invited by the NHIS to participate, and the National Cancer Center (NCC), in cooperation with the NHIS, has overseen the program’s operation and monitoring.

Table 1.

Historical overview of the NCSP in Korea

Year	History
Initial implementation
1999	The NCSP was initially launched for stomach, breast, and cervical cancer, free of charge to MAP recipients
Expansion of target population
2002	Target population was expanded to the lower 20% of the NHIS beneficiaries
2003	Target population was expanded to the lower 30% of the NHIS beneficiaries
2005	Target population was expanded to the lower 50% of the NHIS beneficiaries
2011	Target population for cervical cancer screening was expanded to NHIS dependents aged over 30 y
2015	Target population for cervical cancer screening was expanded to MAP recipients aged over 20 y
2016	Target population for cervical cancer screening was expanded to non-MAP recipients aged over 20 y
Expansion of target cancer types
2003	Liver cancer screening was additionally introduced
2004	Colorectal cancer screening was additionally introduced
2019	Lung cancer screening was additionally introduced
Modifications to screening intervals
2012	Screening intervals for liver and colorectal cancer were unified to 1 y
2016	Screening interval for liver cancer was changed to 6 mo
Financial and procedural revisions
2018	Out-of-pocket cost for colorectal cancer screening was exempted
2023	Double-contrast barium enema was removed from the NCSP

NCSP, National Cancer Screening Program; MAP, Medical Aid Program; NHIS, National Health Insurance Service.

In 2003, the NCSP expanded to the lower 30% of NHIS beneficiaries and incorporated screening for liver cancer, while it added colorectal cancer screening in 2004. In 2005, eligibility was further extended to the lower 50% of NHIS beneficiaries. In 2011, cervical cancer screening was broadened to include NHIS dependents aged ≥30 years; screening among MAP recipients aged ≥20 years began in 2015 and was extended to non-MAP recipients aged ≥20 years in 2016. During this period, the liver cancer screening interval was shortened from 1 year to 6 months. In 2018, out-of-pocket expenses for colorectal cancer screening were waived. Lung cancer screening was introduced in 2019, and in 2023 double-contrast barium enema was removed from the colorectal screening program due to decreased demand.

Currently, the NCSP provides free screening for 6 common cancers (stomach, breast, cervical, liver, colorectal, and lung) to MAP recipients and NHIS beneficiaries in the lower 50% income bracket. For NHIS beneficiaries in the upper 50% bracket, the NHIS covers 90% of the cost of stomach, breast, liver, and lung cancer screening, with individuals responsible for the remaining 10%. In contrast, cervical and colorectal cancer screenings are fully covered, requiring no out-of-pocket expenses.

Development of National Cancer Screening Program Protocols

In response to the need for standardized cancer screening, the Ministry of Health and Welfare and the NCC convened the National Cancer Screening Support and Evaluation Council to develop national cancer screening guidelines [11]. In collaboration with clinical experts and representatives of relevant academic societies, guidelines for 7 major cancers in Korea were published; initial recommendations for stomach, breast, cervical, liver, and colorectal cancers were first published in 2001 and revised in 2015, while guidelines for thyroid and lung cancers were released in 2015 [11]. Drawing on these documents, NCSP protocols for 6 common sites—the stomach, breast, cervix, liver, colorectum, and lung—were developed to specify starting ages, screening intervals, and optimal methods (Table 2). Although these protocols are grounded in scientific evidence, they were modified to account for considerations including available medical resources, cost-effectiveness, budgetary constraints, and policy priorities. Accordingly, for certain cancer types, the NCSP protocol can differ from general screening recommendations in terms of target age (including upper limits), screening interval, and screening methods.

Table 2.

National Cancer Screening Program protocols in Korea

Cancer	Target population	Interval	Test or procedures
Stomach	Adults aged ≥40 y	2 y	Endoscopy or selective upper gastrointestinal series
Liver	High-risk individuals aged ≥40 y1	6 mo	Ultrasonography and serum alpha-fetoprotein test
Colorectum	Adults aged ≥50 y	Annually	Fecal immunochemical test; if positive, then colonoscopy
Breast	Women aged ≥40 y	2 y	Mammography
Cervix	Women aged ≥20 y	2 y	Pap smear
Lung	High-risk individuals aged between 54 and 74 y2	2 y	Low-dose computed tomography

¹Individuals with cirrhosis, antigen positivity for hepatitis B, antibody positivity for hepatitis C, or chronic liver disease caused by hepatitis B or C virus.

²Current smokers with ≥30 pack-years or former smokers who have quit smoking within the past 15 years with ≥30 pack-years.

The NCSP for stomach cancer provides biennial endoscopy or selective upper gastrointestinal series (UGIS) for adults aged ≥40 years. Liver cancer screening comprises combined ultrasonography and serum alpha-fetoprotein testing every 6 months for high-risk individuals aged ≥40 years who are hepatitis B or C antigen-positive or who have liver cirrhosis or chronic liver disease due to hepatitis B or C. For colorectal cancer, adults aged ≥50 years undergo annual fecal immunochemical testing (FIT), with secondary colonoscopy available to confirm positive FIT results. Women aged ≥40 years receive mammography every 2 years, and those aged ≥20 years undergo Pap smear testing at the same interval. Since the implementation of lung cancer screening in 2019, low-dose computed tomography has been provided for high-risk current or former smokers aged 54 years to 74 years with a ≥30 pack-year smoking history.

ACHIEVEMENTS OF THE NATIONAL CANCER SCREENING PROGRAM

Participation Rates

Organized screening programs must achieve widespread coverage and high participation to reduce cancer mortality. Accordingly, the cancer screening rate represents a key performance indicator for evaluating the implementation of the National Cancer Control Plan [12]. In Korea, despite a sharp decrease in 2020 due to coronavirus disease 2019 (COVID-19), NCSP participation for all cancer types has gradually increased since 2002 (Figure 1A) [13,14]. The stomach cancer screening rate rose from 7.4% in 2002 to 63.8% in 2022, while breast cancer screening increased from 9.4% in 2002 to 64.8% in 2022 [13,14]. Liver cancer screening for high-risk groups began in 2003 with an initial participation rate of 10.5% [13], climbing to 74.6% in 2022—the highest among all cancer types [14]. In comparison, colorectal cancer screening started at 7.3% in 2004 and reached 40.4% by 2022, representing the lowest participation rate [13,14]. Cervical cancer screening participation grew from 18.6% in 2005 to 60.3% in 2022 (data from 2002 to 2004 not shown) [13,14].

Figure. 1.

(A) Participation rates in the National Cancer Screening Program, 2002-2022¹. (B) Cancer screening rates with recommendations, 2004-2024². ¹Data from 2002-2009 were obtained from the Reports of the National Cancer Center Intramural Research Program: Advanced Research of the National Cancer Screening Program for Reducing the Burden of Preventable Cancer (2021-2024), while data from 2010-2022 were sourced from the Health Checkup Statistics [13,14]. ²From 2015 onward, cervical cancer screening rates include women aged 20 years or older; Data were obtained from the National Cancer Screening Surveys, 2004-2024 [16].

Korean National Cancer Screening Survey

The NCSP has increased overall cancer screening participation in Korea. Since 2004, the NCC has conducted the Korean National Cancer Screening Survey (KNCSS), an annual population-based survey that measures organized and opportunistic screening rates for the 6 major cancer types [9]. The survey targets cancer-free women aged ≥20 years and men aged ≥40 years [9]. A detailed description of its design and sampling methods has been published previously [15].

KNCSS survey results revealed that NCSP recommendation-based screening rates—the proportion of participants who underwent screening according to NCSP guidelines—rose from 2004 to 2024 for all 6 targeted cancers (Figure 1B) [16]. Among these, colorectal cancer screening exhibited the largest gain, increasing from 19.9% to 70.5% (annual increase, 5.15%) [9]. By 2024, this rate reached 74.4%, primarily driven by higher colonoscopy uptake (56.5% in 2023 to 66.4% in 2024), reflecting a growing preference for colonoscopy [16]. Between 2004 and 2023, liver cancer screening climbed from 20.0% to 48.8% (annual increase, 4.30%) [9], and stomach cancer screening rose from 39.2% to 77.5% (annual increase, 3.50%) [9]. Although breast and cervical cancer screening rates also improved markedly, their annual increases were lower, at 2.88% (33.2 to 72.7%) and 1.08% (58.3 to 70.2%), respectively [9].

Cancer Detection Rates

The cancer detection rate (CDR) is defined as the number of true positive cases—individuals with positive screening tests who are confirmed to have cancer—per 1000 individuals undergoing cancer screening. This rate serves as a key measure of a screening program’s effectiveness in detecting cancer over time. CDRs for major cancers, derived from the NCSP database of the NHIS, were reported for 2002-2019 (data not shown) [13]. For stomach cancer, the CDR increased from 1.17 per 1000 in 2002 to 1.46 per 1000 in 2019 [13]; in 2015-2016, endoscopy yielded a CDR of 1.99 versus 0.26 for UGIS, indicating that endoscopy is more effective in detecting stomach cancer [17]. For liver cancer, the CDR rose from 2.57 in 2003 to 3.44 in 2019 [13]. Similarly, the CDR for breast cancer climbed from 0.61 in 2002 to 2.60 in 2019 [13], with a separate study noting an increase from 1.26 in 2009 to 1.82 in 2014 [18]. The CDR for cervical cancer increased from 1.04 in 2005 to 1.28 in 2022 [13], and detection of cervical carcinoma in situ (CIS) rose significantly from 0.67 in 2005 to 0.83 in 2013 (annual percent change, 3.9%; 95% confidence interval [CI], 1.0 to 6.9), indicating the effectiveness of Pap smear in identifying precancerous lesions [19]. Conversely, the CDR for colorectal cancer gradually decreased from 1.21 in 2004 to 0.90 in 2019 [13]. This decline may reflect greater use of opportunistic colonoscopy outside the NCSP, particularly among high-risk individuals attracted by its superior diagnostic accuracy [16,20]. The 2-step FIT screening process—in which follow-up colonoscopy is required after a positive result—may also contribute to lower detection rates, possibly due to suboptimal adherence to confirmatory testing [21]. Moreover, numerous studies have established that the colonoscopic detection and removal of polyps and adenomas can significantly reduce the incidence of colorectal cancer. Indeed, Korea’s age-standardized incidence rate for colorectal cancer has fallen since 2010, suggesting that rising colonoscopy uptake may have helped drive reductions in both incidence and detection rates [10].

Stage Distribution at Diagnosis

Effective screening programs facilitate early detection and reduce the incidence of late-stage cancer through earlier identification of malignancies or premalignancies [22]. Over the past 18 years in Korea, the proportion of localized diagnoses for major cancers has risen substantially, while regional and distant-stage cases have declined. For stomach cancer, localized cases increased by 18.2 percentage points (%p), from 51.7% in 2005 to 69.8% in 2022 [23]. Breast cancer saw a 9.9-point rise in localized diagnoses, from 54.8% to 64.7%, over the same period [23]. Among CIS cases in 2022, cervical CIS (30.0%) and colorectal CIS (23.0%) represented the highest proportions in both genders [23]. Since 2005, the share of CIS and localized stage cancers has climbed for cervical cancer (from 71.7% in 2005-2006 to 90.8% in 2017-2018) and colorectal cancer (from 32.5 to 47.3%), while the proportions of regional, distant, and unknown-stage presentations have progressively decreased [23].

For cervical cancer, a Korean population-based case-control study revealed that individuals who had ever undergone a Pap smear, compared with those never screened, were significantly more likely to be diagnosed with CIS rather than invasive cancer (adjusted odds ratio [aOR], 2.40; 95% CI, 2.18 to 2.65) [24]. Similarly, mammography increased the likelihood of detecting ductal CIS or localized breast cancer (aOR, 1.41; 95% CI, 1.28 to 1.55) [25]. Stomach cancer screening—by either endoscopy or UGIS—was associated with significantly higher odds of localized-stage diagnosis (aOR, 1.71; 95% CI, 1.60 to 1.82), with endoscopy linked to significantly greater odds (aOR, 2.10; 95% CI, 1.90 to 2.33) than UGIS (aOR, 1.24; 95% CI, 1.13 to 1.36) [26].

Changes in Cancer Incidence and Survival Rates After Introduction of the National Cancer Screening Program

Organized cancer screening programs can reduce cancer incidence by identifying precursors and increase detection at early stages [27-29]. Since the implementation of the NCSP, notable reductions in incidence have been observed for major cancers, especially stomach, liver, colorectal, and cervical cancers. The age-standardized rate (ASR) per 100 000 individuals declined from 86.0 in 1999 to 54.0 in 2022 for stomach cancer, from 52.4 to 27.3 for liver cancer, and from 26.6 to 11.9 for cervical cancer [23]. Although colorectal cancer incidence rose sharply from 1999 to 2010, it then fell at an annual rate of 3.2% between 2010 and 2020 and has since stabilized [23]. Meanwhile, ASRs for the incidence of CIS among NCSP-targeted cancers have increased. Between 1999 and 2022, the CIS ASR per 100 000 rose by 27.9 for cervical cancer (from 14.4 to 42.3), by 23.1 for breast cancer (from 1.7 to 24.8), and by 14.0 for colorectal cancer (from 0.1 to 15.0) [23]. In contrast, the CIS ASR for cancers other than stomach, colorectal, breast, and cervical cancers showed a comparatively small increase of 13.7 (from 0.6 to 14.3) over the same period [23].

The increasing survival rates in Korea can be attributed not only to advancements in treatment but also to the NCSP’s facilitation of early detection and timely intervention. Between patients diagnosed in 2001-2005 and those diagnosed in 2018-2022, the 5-year relative survival rate has steadily increased, by a total of 18.7%p [23]. Stomach cancer exhibited the greatest improvement (20.4%p, from 58.0 to 78.4%), followed by liver cancer (18.8%p, from 20.6 to 39.4%), colorectal cancer (7.6%p, from 67.0 to 74.6%), and breast cancer (5.6%p, from 88.7 to 94.3%) [23].

Reduction in Cancer Mortality

Substantial evidence indicates that cancer screening programs reduce cancer-specific mortality [30-32]. In Korea, several population-based studies have evaluated the effectiveness of the NCSP (Table 3) [33-40]. Stomach cancer screening has been associated with a 21-33% reduction in gastric cancer-specific mortality [33,34]. Notably, endoscopic screening reduced gastric cancer mortality by up to 47%, whereas UGIS did not demonstrate a meaningful benefit [33]. Accordingly, endoscopy has been offered as the primary screening modality in Korea since 2018, with UGIS serving as an alternative for those unable to undergo endoscopy. Similarly, FIT-based colorectal screening reduced mortality by 23-26%, although failure to complete follow-up colonoscopy after positive FIT was associated with a 1.7-fold increase in mortality risk [35-37]. However, the effectiveness of the NCSP regarding cancer-specific mortality varies with age. Among adults aged ≥75 years, reductions in mortality were not statistically significant [33,35]. For cervical cancer, Pap smear screening reduced mortality by 38%, and mammography decreased breast cancer mortality by 35% to 57% [38-40]. In 2016, the Korean government introduced bivalent and quadrivalent human papillomavirus vaccines into its National Immunization Program for 12-year-old girls, extending coverage to adolescents aged 12-17 years in 2022 [41]. Due to the combined effects of cervical cancer screening and vaccination among adolescents reaching adulthood, further declines in cervical cancer incidence and mortality are anticipated, underscoring the long-term impact of cancer control strategies in Korea [41].

Table 3.

Effectiveness of the NCSP in reducing cancer-specific mortality in Korea

Study	Study design	Follow-up period	Sample size	Adjusted variables	Site	Screening methods	Ratio (95% CI)
Lee et al., (2024) [35]	Nested case-control	2004-2015	29 922 case-control pairs	Matched by year of entry, age, sex, and socioeconomic status	Colorectum	FIT	OR, 0.74 (0.71, 0.76)
Luu et al., (2022) [36]	Cohort	2004-2019	32 509 patients with colorectal cancer	Age, sex, socioeconomic status, anatomic site, histological subtype, and cancer stage	Colorectum	FIT	HR, 0.77 (0.73, 0.80)
Kim et al., (2021) [37]	Cohort	2009-2015	258 819 individuals who received positive FOBT results	Age, sex, hospital type, health insurance type, region, health insurance cost, BMI, smoking, drinking, exercise, and CCI	Colorectum	FOBT	HR, 1.70 (1.52, 1.90)1
Luu et al., (2022) [38]	Cohort	2002-2019	24 387 patients with breast cancer	Age, socioeconomic status, anatomic site, histological subtype, and cancer stage	Breast	Mammography	HR, 0.65 (0.60, 0.70)
Choi et al., (2021) [39]	Cohort	2002-2015	8 300 682 female participants	Age and socioeconomic status	Breast	Mammography	RR, 0.43 (0.41, 0.44)
Luu et al., (2022) [40]	Cohort	2002-2019	14 903 patients with cervical cancer	Age, socioeconomic status, anatomic site, histological subtype, and cancer stage	Cervix	Pap smear	HR, 0.62 (0.54, 0.70)
Luu et al., (2022) [34]	Cohort	2002-2019	46 701 patients with gastric cancer	Age, sex, socioeconomic status, anatomic site, histological subtype, and cancer stage	Stomach	All, endoscopy, UGIS	HR, 0.67 (0.65, 0.69)
Jun et al., (2017) [33]	Nested case-control	2002-2015	54 418 case-control pairs	Matched by year of entry, age, sex, and socioeconomic status	Stomach	All, endoscopy, UGIS	OR, 0.79 (0.77, 0.81)

NCSP, National Cancer Screening Program; FIT, fecal immunochemical test; FOBT, fecal occult blood test; BMI, body mass index; CCI, Charlson comorbidity index; UGIS, upper gastrointestinal series; OR, odds ratio; HR, hazard ratio; RR, rate ratio; CI, confidence interval.

¹The value shown corresponds to the non-compliant group, who did not undergo follow-up colonoscopy within 1 year, with the compliant group serving as the reference.

Mortality-to-incidence Ratio

Mortality-to-incidence ratios (MIRs) are critical indicators of disparities in early detection and treatment strategies, evaluating cancer mortality relative to incidence [42]. Based on information from the 2022 GLOBOCAN database, Korea demonstrated markedly lower MIRs for major cancer types than the Organization for Economic Cooperation and Development (OECD) averages across its 38 member countries (Table 4) [1]. These lower MIRs reflect the impact of Korea’s prioritization of early detection and high-quality medical interventions on improving survival rates.

Table 4.

Comparison of MIRs of 38 OECD countries in 2022

OECD country	MIR1
	Stomach	Colorectum	Breast	Cervix
Korea2	0.24	0.27	0.08	0.26
All OECD countries	0.45	0.35	0.16	0.34
Oceania
Australia	0.43	0.25	0.12	0.27
New Zealand	0.57	0.36	0.16	0.29
Northern America
Canada	0.51	0.37	0.15	0.34
USA	0.40	0.29	0.13	0.34
South America
Chile	0.78	0.46	0.27	0.46
Colombia	0.77	0.48	0.26	0.50
Central America
Costa Rica	0.68	0.60	0.28	0.43
Mexico	0.75	0.50	0.26	0.47
Eastern Europe
Czechia	0.70	0.40	0.16	0.40
Hungary	0.72	0.46	0.22	0.38
Poland	0.74	0.51	0.26	0.46
Slovakia	0.77	0.48	0.27	0.40
Western Europe
Austria	0.55	0.38	0.21	0.32
Belgium	0.42	0.32	0.14	0.30
France (metropolitan)	0.59	0.32	0.15	0.35
Germany	0.55	0.37	0.21	0.32
Luxembourg	0.55	0.35	0.15	0.40
The Netherlands	0.56	0.29	0.14	0.25
Switzerland	0.54	0.29	0.16	0.26
Northern Europe
Denmark	0.61	0.24	0.15	0.18
Estonia	0.67	0.43	0.21	0.33
Finland	0.62	0.33	0.13	0.28
Iceland	0.53	0.34	0.24	0.29
Ireland	0.58	0.36	0.19	0.31
Latvia	0.68	0.49	0.25	0.35
Lithuania	0.76	0.54	0.23	0.49
Norway	0.55	0.31	0.12	0.15
Sweden	0.56	0.34	0.15	0.24
UK	0.64	0.38	0.15	0.26
Southern Europe
Greece	0.61	0.38	0.18	0.40
Portugal	0.62	0.36	0.16	0.31
Italy	0.66	0.35	0.17	0.32
Slovenia	0.59	0.37	0.18	0.33
Spain	0.63	0.33	0.13	0.29
Eastern Asia
Japan	0.26	0.31	0.13	0.20
Western Asia
Israel	0.60	0.35	0.21	0.35
Türkiye	0.80	0.51	0.27	0.43

MIR, mortality-to-incidence ratio; OECD, Organization for Economic Cooperation and Development; ASR, age-standardized rate.

¹MIRs were calculated using the 2022 GLOBOCAN observatory database [1]; MIR: The ASR for mortality per 100 000 divided by the ASR for incidence per 100 000.

²ASR incidence rates were derived from Korean cancer statistics and standardized using Segi’s world standard population [23,43].

Korea’s ASR for stomach cancer (26.8 per 100 000) is the highest among OECD countries, which exhibit an average ASR of 9.7; nevertheless, its MIR is 0.24, substantially lower than the OECD average of 0.45 (Table 4) [23,43] (Supplementary Materials 1 and 2). This disparity underscores the impact of Korea’s well-established nationwide cancer screening programs and robust national cancer control policies. Similarly, the MIR for cervical cancer in Korea was 0.26 compared with the OECD average of 0.34. Furthermore, the MIRs for colorectal and breast cancers stand at 0.27 and 0.08, respectively, which are below the OECD averages of 0.35 and 0.16. These outcomes reflect the effectiveness of early detection programs—including FIT, colonoscopy, and mammography—and advances in treatment accessibility that together facilitate earlier diagnosis and improved survival rates in Korea.

DISCUSSION

Over the past 20 years, the Korean NCSP has effectively reduced cancer incidence and mortality. Nonetheless, to further decrease the cancer burden, ongoing challenges must be addressed. Continuous refinement of the NCSP, achieved through updates to evidence-based screening guidelines, will be essential to enhance screening effectiveness.

First, as Korea is undergoing rapid demographic aging, it is crucial to optimize national cancer screening strategies for older adults. In 2023, approximately 40% of individuals aged ≥75 years underwent cancer screening [44]. However, among older adults with limited life expectancy, the long-delayed benefits of screening may be outweighed by immediate risks, such as complications, overdiagnosis, and psychological distress. The USPSTF recommends discontinuing cancer screening in older adults when the expected benefit is minimal; in contrast, the Korean NCSP currently lacks such discontinuation thresholds for older adults except in lung cancer screening, underscoring the need for evidence-based criteria [5-8].

Second, stringent quality control is essential for implementing population-based primary colonoscopy screening. In the Fourth National Cancer Control Plan (2021-2025), colonoscopy is recommended as the primary colorectal cancer screening method [12]. In response to the growing demand for colonoscopy, the Korean Colonoscopy Screening Pilot Study was launched in 2019 to evaluate its feasibility at the national level [45]. The effectiveness of colonoscopy depends heavily on the skill and experience of the endoscopist, which can markedly influence key performance indicators, such as adenoma detection, cecal intubation, and complication rates [46]. Standardized training, ongoing education, and rigorous quality assurance are thus crucial to increase diagnostic accuracy and minimize complications. Continuous monitoring of procedural outcomes and adherence to guidelines are critical for maintaining the long-term safety and effectiveness of colonoscopy-based screening within the NCSP.

Finally, targeted screening of high-risk groups is crucial for early detection and mortality reduction in liver and lung cancers. Liver cancer has well-established risk factors, with approximately 90% of cases associated with etiologies such as liver cirrhosis or chronic hepatitis B or C infection [47]. This strong association underlies surveillance recommendations for high-risk populations, as outlined in most clinical guidelines, and has been shown to reduce liver cancer mortality [47,48]. Similarly, the Korean Lung Cancer Screening Project, launched in 2016, demonstrated higher early-stage lung CDRs and lower false-positive and complication rates than earlier clinical trials [49]. Consequently, the National Lung Cancer Screening Program was implemented in 2019. Korea is one of the few countries to incorporate targeted high-risk screening for liver and lung cancers within its NCSP. Despite its potential effectiveness, continuous monitoring and evidence-based research are essential to assess both the benefits and harms of these pioneering high-risk screening efforts.

CONCLUSION

The steady rise in screening participation has facilitated earlier cancer detection in Korea, ultimately reducing the cancer burden at the population level. Nonetheless, ongoing efforts are required to refine screening strategies—particularly for older adults and high-risk groups—and to improve overall screening quality. Future research should prioritize generating robust evidence for the NCSP by evaluating the benefits and harms of screening in older adults, validating the safety and effectiveness of primary colonoscopy as a screening modality, and assessing the appropriateness and long-term outcomes of targeted screening strategies for high-risk populations. Large-scale, population-based studies conducted within the NCSP framework are essential to inform evidence-based updates to screening guidelines and ensure optimal resource allocation.

Ethics Statement

This study was exempt from institutional review board approval because it is a special article based on a literature review and analysis of existing data.

Supplemental Materials

Supplemental materials are available at https://doi.org/10.3961/jpmph.25.268.