Purpose: To develop the 2025 update to the Korean colorectal cancer (CRC) screening guidelines by systematically evaluating recent evidence, integrating domestic data, and addressing changes since the 2015 guideline revision, thereby providing an evidence-based standard for clinicians and policymakers. Methods: A multidisciplinary committee developed the guidelines using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. The process included formulation of three key questions addressing screening efficacy, diagnostic accuracy, and optimal screening age and interval. A systematic review of international guidelines and primary literature was conducted, yielding 327 eligible studies. In addition, a utility-based analysis using a Markov model was performed to determine optimal screening ages and intervals. Results: The evidence synthesis identified high-certainty evidence supporting the use of the fecal immunochemical test (FIT) for reducing CRC mortality and moderate-certainty evidence for colonoscopy. Evidence for computed tomographic colonography (CTC) and stool DNA testing was rated as very low certainty. Based on the evidence review and cost-utility analysis, the committee conditionally recommends CRC screening for asymptomatic, average-risk adults aged 45–74 years using either colonoscopy every 10 years or FIT every 1–2 years. CTC and stool DNA testing were not recommended owing to insufficient evidence. Conclusion The 2025 Korean Guidelines for Colorectal Cancer Screening present updated, evidence-based recommendations tailored to the domestic healthcare context. By conditionally endorsing both colonoscopy and FIT for individuals aged 45–74 years, these guidelines aim to improve population-level screening effectiveness and reduce the burden of CRC in South Korea.

Background: s/Aims: Hepatocellular carcinoma (HCC) is the sixth most common cancer and second leading cause of cancer-related deaths in South Korea. This study evaluated the characteristics of Korean patients newly diagnosed with HCC in 2016-2018. Methods: Data from the Korean Primary Liver Cancer Registry (KPLCR), a representative database of patients newly diagnosed with HCC in South Korea, were analyzed. This study investigated 4,462 patients with HCC registered in the KPLCR in 2016-2018. Results: The median patient age was 63 years (interquartile range, 55-72). 79.7% of patients were male. Hepatitis B infection was the most common underlying liver disease (54.5%). The Barcelona Clinic Liver Cancer (BCLC) staging system classified patients as follows: stage 0 (14.9%), A (28.8%), B (7.5%), C (39.0%), and D (9.8%). The median overall survival was 3.72 years (95% confidence interval, 3.47-4.14), with 1-, 3-, and 5-year overall survival rates of 71.3%, 54.1%, and 44.3%, respectively. In 2016-2018, there was a significant shift toward BCLC stage 0-A and Child-Turcotte-Pugh liver function class A (P<0.05), although survival rates did not differ by diagnosis year. In the treatment group (n=4,389), the most common initial treatments were transarterial therapy (31.7%), surgical resection (24.9%), best supportive care (18.9%), and local ablation therapy (10.5%). Conclusions Between 2016 and 2018, HCC tended to be diagnosed at earlier stages, with better liver function in later years. However, since approximately half of the patients remained diagnosed at an advanced stage, more rigorous and optimized HCC screening strategies should be implemented.

Background: s/Aims: Hepatocellular carcinoma (HCC) is the sixth most common cancer and second leading cause of cancer-related deaths in South Korea. This study evaluated the characteristics of Korean patients newly diagnosed with HCC in 2016-2018. Methods: Data from the Korean Primary Liver Cancer Registry (KPLCR), a representative database of patients newly diagnosed with HCC in South Korea, were analyzed. This study investigated 4,462 patients with HCC registered in the KPLCR in 2016-2018. Results: The median patient age was 63 years (interquartile range, 55-72). 79.7% of patients were male. Hepatitis B infection was the most common underlying liver disease (54.5%). The Barcelona Clinic Liver Cancer (BCLC) staging system classified patients as follows: stage 0 (14.9%), A (28.8%), B (7.5%), C (39.0%), and D (9.8%). The median overall survival was 3.72 years (95% confidence interval, 3.47-4.14), with 1-, 3-, and 5-year overall survival rates of 71.3%, 54.1%, and 44.3%, respectively. In 2016-2018, there was a significant shift toward BCLC stage 0-A and Child-Turcotte-Pugh liver function class A (P<0.05), although survival rates did not differ by diagnosis year. In the treatment group (n=4,389), the most common initial treatments were transarterial therapy (31.7%), surgical resection (24.9%), best supportive care (18.9%), and local ablation therapy (10.5%). Conclusions Between 2016 and 2018, HCC tended to be diagnosed at earlier stages, with better liver function in later years. However, since approximately half of the patients remained diagnosed at an advanced stage, more rigorous and optimized HCC screening strategies should be implemented.

Background: s/Aims: Hepatocellular carcinoma (HCC) is the sixth most common cancer and second leading cause of cancer-related deaths in South Korea. This study evaluated the characteristics of Korean patients newly diagnosed with HCC in 2016-2018. Methods: Data from the Korean Primary Liver Cancer Registry (KPLCR), a representative database of patients newly diagnosed with HCC in South Korea, were analyzed. This study investigated 4,462 patients with HCC registered in the KPLCR in 2016-2018. Results: The median patient age was 63 years (interquartile range, 55-72). 79.7% of patients were male. Hepatitis B infection was the most common underlying liver disease (54.5%). The Barcelona Clinic Liver Cancer (BCLC) staging system classified patients as follows: stage 0 (14.9%), A (28.8%), B (7.5%), C (39.0%), and D (9.8%). The median overall survival was 3.72 years (95% confidence interval, 3.47-4.14), with 1-, 3-, and 5-year overall survival rates of 71.3%, 54.1%, and 44.3%, respectively. In 2016-2018, there was a significant shift toward BCLC stage 0-A and Child-Turcotte-Pugh liver function class A (P<0.05), although survival rates did not differ by diagnosis year. In the treatment group (n=4,389), the most common initial treatments were transarterial therapy (31.7%), surgical resection (24.9%), best supportive care (18.9%), and local ablation therapy (10.5%). Conclusions Between 2016 and 2018, HCC tended to be diagnosed at earlier stages, with better liver function in later years. However, since approximately half of the patients remained diagnosed at an advanced stage, more rigorous and optimized HCC screening strategies should be implemented.

Objective: This was a retrospective investigation conducted to evaluate the impact of the coronavirus disease-2019 (COVID-19) pandemic on the treatment and outcomes of patients with ischemic stroke. Methods: Data were collected over one year for the COVID-19 and pre-COVID-19 (control) groups, from May 1, 2020, to April 30, 2021, when COVID-19 was prevalent in Korea, and from May 1, 2018 to April 30, 2019, before the COVID-19 outbreak, respectively. Adult patients diagnosed with acute cerebral infarction at three emergency medical centers during the study period were included. COVID-19-positive patients (i.e., those with COVID-19 symptoms but those who tested positive) were excluded from this study to ensure only the evaluation of delays in stroke treatment due to the pandemic. Results: During the COVID-19 pandemic, of the total of 82,558 patients who visited the emergency centers, 710 were diagnosed with ischemic stroke. The study observed that the pandemic caused process delays for these patients, resulting in longer wait times for brain CT scans (P=0.010, P<0.001) and emergency room stays (P=0.0055, P<0.001) during the COVID-19 period. However, the length of time for administration of tissue plasminogen activator remained relatively constant. Notably, the 28-day mortality rate was considerably higher for patients with COVID-19-related symptoms during the pandemic (13.6% vs 3.1%; P=0.006). A cumulative risk analysis revealed an increased mortality risk for patients with COVID-19 related symptoms (P=0.005). Conclusion This study showed the need to improve emergency care procedures during pandemics to ensure prompt treatment of ischemic stroke. Preparation and resource allocation for ischemic stroke patients with COVID-19 symptoms are crucial.

Objective: This was a retrospective investigation conducted to evaluate the impact of the coronavirus disease-2019 (COVID-19) pandemic on the treatment and outcomes of patients with ischemic stroke. Methods: Data were collected over one year for the COVID-19 and pre-COVID-19 (control) groups, from May 1, 2020, to April 30, 2021, when COVID-19 was prevalent in Korea, and from May 1, 2018 to April 30, 2019, before the COVID-19 outbreak, respectively. Adult patients diagnosed with acute cerebral infarction at three emergency medical centers during the study period were included. COVID-19-positive patients (i.e., those with COVID-19 symptoms but those who tested positive) were excluded from this study to ensure only the evaluation of delays in stroke treatment due to the pandemic. Results: During the COVID-19 pandemic, of the total of 82,558 patients who visited the emergency centers, 710 were diagnosed with ischemic stroke. The study observed that the pandemic caused process delays for these patients, resulting in longer wait times for brain CT scans (P=0.010, P<0.001) and emergency room stays (P=0.0055, P<0.001) during the COVID-19 period. However, the length of time for administration of tissue plasminogen activator remained relatively constant. Notably, the 28-day mortality rate was considerably higher for patients with COVID-19-related symptoms during the pandemic (13.6% vs 3.1%; P=0.006). A cumulative risk analysis revealed an increased mortality risk for patients with COVID-19 related symptoms (P=0.005). Conclusion This study showed the need to improve emergency care procedures during pandemics to ensure prompt treatment of ischemic stroke. Preparation and resource allocation for ischemic stroke patients with COVID-19 symptoms are crucial.

Objective: This was a retrospective investigation conducted to evaluate the impact of the coronavirus disease-2019 (COVID-19) pandemic on the treatment and outcomes of patients with ischemic stroke. Methods: Data were collected over one year for the COVID-19 and pre-COVID-19 (control) groups, from May 1, 2020, to April 30, 2021, when COVID-19 was prevalent in Korea, and from May 1, 2018 to April 30, 2019, before the COVID-19 outbreak, respectively. Adult patients diagnosed with acute cerebral infarction at three emergency medical centers during the study period were included. COVID-19-positive patients (i.e., those with COVID-19 symptoms but those who tested positive) were excluded from this study to ensure only the evaluation of delays in stroke treatment due to the pandemic. Results: During the COVID-19 pandemic, of the total of 82,558 patients who visited the emergency centers, 710 were diagnosed with ischemic stroke. The study observed that the pandemic caused process delays for these patients, resulting in longer wait times for brain CT scans (P=0.010, P<0.001) and emergency room stays (P=0.0055, P<0.001) during the COVID-19 period. However, the length of time for administration of tissue plasminogen activator remained relatively constant. Notably, the 28-day mortality rate was considerably higher for patients with COVID-19-related symptoms during the pandemic (13.6% vs 3.1%; P=0.006). A cumulative risk analysis revealed an increased mortality risk for patients with COVID-19 related symptoms (P=0.005). Conclusion This study showed the need to improve emergency care procedures during pandemics to ensure prompt treatment of ischemic stroke. Preparation and resource allocation for ischemic stroke patients with COVID-19 symptoms are crucial.

Background: The relationship between early life factors and childhood pulmonary function and structure in preterm infants remains unclear.Purpose: This study investigated the impact of bronchopulmonary dysplasia (BPD) and perinatal factors on childhood pulmonary function and structure. Methods: This longitudinal cohort study included preterm participants aged ≥5 years born between 2005 and 2015. The children were grouped by BPD severity according to National Institutes of Health criteria. Pulmonary function tests (PFTs) were performed using spirometry. Chest computed tomography (CT) scans were obtained and scored for hyperaeration or parenchymal lesions. PFT results and chest CT scores were analyzed with perinatal factors. Results: A total 150 children (66 females) aged 7.7 years (6.4–9.9 years) were categorized into non/mild BPD (n=68), moderate BPD (n=39), and severe BPD (n=43) groups. The median z score for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and forced midexpiratory flow (FEF25%–75%) were significantly lower in the severe versus non/mild BPD group (-1.24 vs. -0.18, -0.22 vs. 0.41, -1.80 vs. -1.12, and -1.88 vs. -1.00, respectively; all P<0.05). The median z scores of FEV1, FEV1/ FVC, and FEF25%–75% among asymptomatic patients were also significantly lower in the severe versus non/mild BPD group (-0.82 vs. 0.09, -1.68 vs. -0.87, -1.59 vs. -0.61, respectively; all P<0.05). The severe BPD group had a higher median (range) CT score than the non/mild BPD group (6 [0–12] vs. 1 [0–10], P<0.001). Prenatal oligohydramnios was strongly associated with both low pulmonary function (FEV1/FVCConclusion School-aged children with severe BPD showed airflow limitations and structural abnormalities despite no subjective respiratory symptoms. These results suggest that patients with a history of prenatal oligohydramnios or prolonged mechanical ventilation require extended follow-up.

Background: The relationship between early life factors and childhood pulmonary function and structure in preterm infants remains unclear.Purpose: This study investigated the impact of bronchopulmonary dysplasia (BPD) and perinatal factors on childhood pulmonary function and structure. Methods: This longitudinal cohort study included preterm participants aged ≥5 years born between 2005 and 2015. The children were grouped by BPD severity according to National Institutes of Health criteria. Pulmonary function tests (PFTs) were performed using spirometry. Chest computed tomography (CT) scans were obtained and scored for hyperaeration or parenchymal lesions. PFT results and chest CT scores were analyzed with perinatal factors. Results: A total 150 children (66 females) aged 7.7 years (6.4–9.9 years) were categorized into non/mild BPD (n=68), moderate BPD (n=39), and severe BPD (n=43) groups. The median z score for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and forced midexpiratory flow (FEF25%–75%) were significantly lower in the severe versus non/mild BPD group (-1.24 vs. -0.18, -0.22 vs. 0.41, -1.80 vs. -1.12, and -1.88 vs. -1.00, respectively; all P<0.05). The median z scores of FEV1, FEV1/ FVC, and FEF25%–75% among asymptomatic patients were also significantly lower in the severe versus non/mild BPD group (-0.82 vs. 0.09, -1.68 vs. -0.87, -1.59 vs. -0.61, respectively; all P<0.05). The severe BPD group had a higher median (range) CT score than the non/mild BPD group (6 [0–12] vs. 1 [0–10], P<0.001). Prenatal oligohydramnios was strongly associated with both low pulmonary function (FEV1/FVCConclusion School-aged children with severe BPD showed airflow limitations and structural abnormalities despite no subjective respiratory symptoms. These results suggest that patients with a history of prenatal oligohydramnios or prolonged mechanical ventilation require extended follow-up.

Background: The relationship between early life factors and childhood pulmonary function and structure in preterm infants remains unclear.Purpose: This study investigated the impact of bronchopulmonary dysplasia (BPD) and perinatal factors on childhood pulmonary function and structure. Methods: This longitudinal cohort study included preterm participants aged ≥5 years born between 2005 and 2015. The children were grouped by BPD severity according to National Institutes of Health criteria. Pulmonary function tests (PFTs) were performed using spirometry. Chest computed tomography (CT) scans were obtained and scored for hyperaeration or parenchymal lesions. PFT results and chest CT scores were analyzed with perinatal factors. Results: A total 150 children (66 females) aged 7.7 years (6.4–9.9 years) were categorized into non/mild BPD (n=68), moderate BPD (n=39), and severe BPD (n=43) groups. The median z score for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and forced midexpiratory flow (FEF25%–75%) were significantly lower in the severe versus non/mild BPD group (-1.24 vs. -0.18, -0.22 vs. 0.41, -1.80 vs. -1.12, and -1.88 vs. -1.00, respectively; all P<0.05). The median z scores of FEV1, FEV1/ FVC, and FEF25%–75% among asymptomatic patients were also significantly lower in the severe versus non/mild BPD group (-0.82 vs. 0.09, -1.68 vs. -0.87, -1.59 vs. -0.61, respectively; all P<0.05). The severe BPD group had a higher median (range) CT score than the non/mild BPD group (6 [0–12] vs. 1 [0–10], P<0.001). Prenatal oligohydramnios was strongly associated with both low pulmonary function (FEV1/FVCConclusion School-aged children with severe BPD showed airflow limitations and structural abnormalities despite no subjective respiratory symptoms. These results suggest that patients with a history of prenatal oligohydramnios or prolonged mechanical ventilation require extended follow-up.