Eun Cho

BACKGROUND: Although screening is necessary where gastric cancer is particularly common in Asia, the performance outcomes of mass screening programs have remained unclear. This study was conducted to evaluate cost-effectiveness outcomes of the national cancer screening program (NCSP) for gastric cancer in South Korea. MATERIALS AND METHODS: People aged 40 years or over during 2002-2003 (baseline) were the target population. Screening recipients and patients diagnosed with gastric cancers were identified using the NCSP and Korea Central Cancer Registry databases. Clinical outcomes were measured in terms of mortality and life-years saved (LYS) of gastric cancer patients during 7 years based on merged data from the Korean National Health Insurance Corporation and National Statistical Office. We considered direct, indirect, and productivity-loss costs associated with screening attendance. Incremental cost-effectiveness ratio (ICER) estimates were produced according to screening method, sex, and age group compared to non-screening. RESULTS: The age-adjusted ICER for survival was 260,201,000-371,011,000 Korean Won (KW; 1USD=1,088 KW) for the upper-gastrointestinal (UGI) tract over non-screening. Endoscopy ICERs were lower (119,099,000-178,700,000 KW/survival) than UGI. To increase 1 life-year, additional costs of approximately 14,466,000-15,014,000 KW and 8,817,000-9,755,000 KW were required for UGI and endoscopy, respectively. Endoscopy was the most cost-effective strategy for males and females. With regard to sensitivity analyses varying based on the upper age limit, endoscopy NCSP was dominant for both males and females. For males, an upper limit of age 75 or 80 years could be considered. ICER estimates for LYS indicate that the gastric cancer screening program in Korea is cost-effective. CONCLUSION: Endoscopy should be recommended as a first-line method in Korea because it is beneficial among the Korean population.

OBJECTIVES: To investigate the feasibility of a computer-aided diagnosis (CAD) system (S-Detect; Samsung Medison, Co, Ltd, Seoul, Korea) for breast ultrasonography (US), according to radiologists with various degrees of experience in breast imaging. METHODS: From December 2015 to March 2016, 119 breast masses in 116 women were included. Ultrasonographic images of the breast masses were retrospectively reviewed and analyzed by 2 radiologists specializing in breast imaging (7 and 1 years of experience, respectively) and S-Detect, according to the individual ultrasonographic descriptors from the fifth edition of the American College of Radiology Breast Imaging Reporting and Data System and final assessment categories. Diagnostic performance and the interobserver agreement among the radiologists and S-Detect was calculated and compared. RESULTS: Among the 119 breast masses, 54 (45.4%) were malignant, and 65 (54.6%) were benign. Compared to the radiologists, S-Detect had higher specificity (90.8% compared to 49.2% and 55.4%) and positive predictive value (PPV; 86.7% compared to 60.7% and 63.8%) (all P < .001). Both radiologists had significantly improved specificity, PPV, and accuracy when using S-Detect compared to US alone (all P < .001). The area under the receiving operating characteristic curves of the both radiologists did not show a significant improvement when applying S-Detect compared to US alone (all P > .05). Moderate agreement was seen in final assessments made by each radiologist and S-Detect (κ = 0.40 and 0.45, respectively). CONCLUSIONS: S-Detect is a clinically feasible diagnostic tool that can be used to improve the specificity, PPV, and accuracy of breast US, with a moderate degree of agreement in final assessments, regardless of the experience of the radiologist.

AIM: The purpose of this study was to determine the significance of a non-mass lesion (NML) which is recognized during screening breast ultrasound (US). MATERIALS AND METHODS: We included patients with a NML on screening breast US and no suspicious finding on mammography between March 2008 and June 2012. The final diagnoses were based on pathology results and a clinical or sonographic follow-up for more than 12 months. We calculated the incidence, likelihood of malignancy, and positive predictive value (PPV) of biopsy with a review of imaging and histopathological findings. RESULTS: A total of 17868 screening breast US were performed in 8856 asymptomatic patients. Ninety-five NMLs were detected in 88 patients (1.0%). Among the 93 lesions that were followed or confirmed histopathologically, 2 (2.2%) were malignant, 89 (95.6%) were benign, and 2 (2.2%) were high risk lesions. The likelihood of malignancy in a NML on screening breast US was 2.2% and the PPV of biopsy was 6.3% (2 of 32). CONCLUSION: The likelihood of malignancy for a NML on screening breast US was greater than 2%. It could be classified as a BI-RADS category 4a lesion and tissue diagnosis is warranted. This provides the potential management guidelines for a NML in screening patients and further prospective studies in a large, multicenter screening population are required.