The COVID-19 Vaccine Safety Research Center: a cornerstone for strengthening safety evidence for COVID-19 vaccination in the Republic of Korea.

The COVID-19 Vaccine Safety Research Committee (CoVaSC) was established in November 2021 to address the growing need for independent, in-depth scientific evidence on adverse events (AEs) following coronavirus disease 2019 (COVID-19) vaccination. This initiative was requested by the Korea Disease Control and Prevention Agency and led by the National Academy of Medicine of Korea. In September 2022, the COVID-19 Vaccine Safety Research Center was established, strengthening CoVaSC's initiatives. The center has conducted various studies on the safety of COVID-19 vaccines. During CoVaSC's second research year, from September 29, 2022 to July 19, 2023, the center was restructured into 4 departments: Epidemiological Research, Clinical Research, Communication & Education, and International Cooperation & Policy Research. Its main activities include (1) managing CoVaSC and the COVID-19 Vaccine Safety Research Center, (2) surveying domestic and international trends in AE causality investigation, (3) assessing AEs following COVID-19 vaccination, (4) fostering international collaboration and policy research, and (5) organizing regular fora and training sessions for the public and clinicians. Causality assessments have been conducted for 27 diseases, and independent research has been conducted after organizing ad hoc committees comprising both epidemiologists and clinical experts on each AE of interest. The research process included protocol development, data analysis, interpretation of results, and causality assessment. These research outcomes have been shared transparently with the public and healthcare experts through various fora. The COVID-19 Vaccine Safety Research Center plans to continue strengthening and expanding its research activities to provide reliable, high-quality safety information to the public.

Association of Neoadjuvant Chemotherapy With Postoperative Outcomes in Immediate Prepectoral Prosthetic Breast Reconstruction.

PURPOSE: Neoadjuvant chemotherapy (NACT) followed by total mastectomy and immediate reconstruction has become an important strategy in the treatment of breast cancer. Although the safety of subpectoral implant-based breast reconstruction with NACT has been extensively evaluated, the safety in prepectoral reconstruction has not been clearly elucidated. We aimed to evaluate the association of NACT with immediate prepectoral breast reconstruction outcomes. METHODS: A retrospective review of patients who underwent total mastectomy and immediate implant-based prepectoral breast reconstruction between May and December 2021 was conducted. Patients were categorized into 2 groups: those receiving NACT and those not receiving it. Postoperative complication rates were compared between the 2 groups. The independent association between NACT and the complication profiles was evaluated. Propensity score matching was also conducted. RESULTS: We analyzed 343 cases, including 85 who received NACT treatment and 258 who did not. Compared with the non-NACT group, the NACT group was younger, had a higher body mass index, and a higher rate of adjuvant radiotherapy. There were no differences in the rates of overall complications or type of complication between the 2 groups. In the multivariable logistic analyses, NACT did not show a significant association with the development of adverse outcomes. Similar results were observed in propensity score matching analyses. CONCLUSIONS: Our results suggest that receiving NACT may not have a significant detrimental effect on the postoperative outcomes of immediate prepectoral prosthetic reconstructions. Conducting prepectoral implant-based reconstruction in the setting of NACT might be safe and provide acceptable outcomes.

Adherence to the World Cancer Research Fund/American Institute for Cancer Research and Korean Cancer Prevention Guidelines and cancer risk: a prospective cohort study from the Health Examinees-Gem study.

OBJECTIVES: The purpose of this study was to explore the association between adherence to 2 cancer prevention recommendations and cancer risk. METHODS: In total, 104,386 individuals aged 40-69 years old who were recruited between 2004 and 2013 in the Health Examinees-Gem study were included. Adherence scores were constructed based on 8 items from the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations, including body weight, physical activity, diet, alcohol consumption and breastfeeding, and on 6 items from the Korean cancer prevention guidelines (smoking status, eating vegetables and fruits, salty foods, alcohol intake, physical activity, and body weight). A Cox proportional hazards model was used to estimate the associations between adherence scores and the risk of total and 5 major cancers. RESULTS: The multivariable hazard ratio (HR) for total cancer with the high adherence score versus the lowest score (4.25-7.00 vs. 0.00-3.25) for the WCRF/AICR guidelines was 0.91 (95% confidence interval [CI], 0.82 to 1.00) in men. A reduced breast cancer risk was observed among women with the highest score. Men within the highest category of the Korean cancer prevention guideline score (3.25-6.00) had an HR of 0.80 (95% CI, 0.73 to 0.88) for developing total cancer compared to men within the lowest score (0.00-2.50). The higher adherence group among men showed lower risks of developing stomach, colorectal, and lung cancers. CONCLUSIONS: Adhering to guidelines for cancer prevention can help to reduce the risk of developing cancer in Korean men. The association might differ by cancer type and gender.

Usefulness of resorbable plate in auricular elevation in two-stage microtia reconstruction.

BACKGROUND: Achieving a well-reconstructed retroauricular sulcus with satisfactory projection and a sufficiently deep retroauricular sulcus is important and at the same time challenging. The selection of the support material is crucial to obtain a sustainable, deep sulcus. The costal cartilage is the conventional material of choice. However, risk of slippage of inserted cartilage and donor site morbidity exists. Resorbable plates are durable, easy to secure and can be easily modified into desired shape. The current study aimed to demonstrate the effectiveness of using a resorbable plate for auricular elevation. METHODS: Retrospective review of patients who received auricular elevation with resorbable plates from December 2020 to October 2022 was performed. Patients demographics, number of inserted plates and screws, postoperative complication were analyzed. RESULTS: Of 65 patients with microtia who underwent auricular reconstruction, resorbable plates were applied to 12 patients. Mean follow up period was 198 (range, 86-360) days. Auricular elevation was performed with one plate at cavum conchae and remnant rib cartilage at the helix in 10 patients (87)%. Two patients had resorbable plate as support material at the both sites. Regarding postoperative complications, there were no hematoma, seroma, plate exposure or plate fracture. Two patients suffered wound problems. One patient recovered only with conservative management. The other healed completely after debridement and intravenous antibiotics administration without undesired change of shape of ear. CONCLUSIONS: We suggest using resorbable plates as an ideal support material, as it can provide firm support to achieve appropriate depth of sulcus without excessive bulk.

Coverage of radial forearm free flap donor site defect using another free flap.

BACKGROUND: Donor site defects following the radial forearm flap (RFF) harvest have been usually covered with skin grafting, which often lead to suboptimal outcomes and donor morbidities, including delayed healing and scar contractures. The present report aimed to evaluate the outcomes of using another free flap, the domino flap, for coverage of donor site defects following RFFF harvest. METHODS: Five patients (two males and three females) who underwent coverage of donor defects of RFFF using another free flap between 2019 and 2021 were reviewed. Their mean age was 74 years and the mean dimension of the defect of the RFF donor site was 8.7 × 5.6 cm. Four patients used an anterolateral thigh flap and one used a superficial circumflex iliac artery perforator flap. RESULTS: The mean size of the domino flaps were 12.2 × 5.8 cm. Distal stumps of radial vessels adopting retrograde flow were used as recipients in four cases, and proximal ones adopting anterograde in one. The donor site of the domino flaps was primarily closed. All patients recovered well without any postoperative complications. Aesthetically pleasing outcomes with no functional impairment related to scar contractures were observed in the donor site of RFF during the mean follow-up of 15.7 months. CONCLUSIONS: Use of another free flap for coverage of RFFF donor defects may provide rapid wound healing and satisfactory outcomes, and may be considered an alternative option in cases with large-sized defects that are expected to take a long time to achieve complete healing with skin grafting.

Impact of pre- and post-diagnosis physical activity on the mortality of patients with cancer: Results from the Health Examinees-G study in Korea.

BACKGROUND: Physical activity (PA) is recommended to improve the survival of cancer patients. However, the prognostic impact of specific PAs is not well understood. Therefore, we investigated the associations of the duration, type, intensity, and number of PAs one participates in pre- and post-diagnosis with mortality in Korean patients with cancer. METHODS: Among the participants aged 40-69 years recruited from the Health Examines study, those diagnosed with cancer after baseline (n = 7749) and within 10 years before baseline (n = 3008) were included in the analyses for pre- and post-diagnosis PA, respectively. Duration, intensity, type, and number of leisure-time physical activities participated in were assessed using questionnaires. The Cox proportional hazard model was used to characterize the association between PA and cancer-specific mortality, adjusting for demographics, behaviors, comorbidities, and cancer stage based on the Surveillance, Epidemiology, and End Results program. RESULTS: Pre-diagnosis, patients participating in vigorous-intensity activities (hazard ratio [HR]: 0.70, 95% confidence interval [CI]: 0.61-0.82), walking (HR: 0.85, 95% CI: 0.74-0.97), climbing (HR: 0.65, 95% CI: 0.55-0.77), sports (HR: 0.39, 95% CI: 0.25-0.61), and more than two activities (HR: 0.73, 95% CI: 0.63-0.86) had significantly lower all-cause mortality. Importantly, these associations were only found in patients with colorectal cancer participating in vigorous-intensity activities (HR: 0.40, 95% CI: 0.23-0.70). Post-diagnosis, only patients who performed more than two activities (HR: 0.65, 95% CI: 0.44-0.95) had significantly lower all-cause mortality. Similar associations were found for cancer mortality, both pre- and post-diagnosis. CONCLUSION: Specific characteristics of PA pre- and post-diagnosis may influence the survival of cancer patients.

Food Allocation under Asynchronous Hatching Conditions of Great Tits (Parus major).

The brood reduction hypothesis, which explains asynchronous hatching in birds, as an adaptation that enables selective survival of older nestlings when availability of food is unpredictable. This study was conducted in order to determine whether the brood reduction hypothesis can explain asynchronous hatching in passerines. Infrared cameras were installed inside nest boxes where great tits (Parus major) were attempting to reproduce in order to determine whether the parents practiced selective feeding of older nestlings. According to the results of the study, no significant difference was observed between the hatching order and the average number of feedings per nestling. In addition, when examining the distribution of food according to hatching order over time, every 30 min, beginning at 9 a.m., selective distribution of food to older nestlings was not observed. In conclusion, use of the brood reduction hypothesis, which supports selective provision of beneficial feeding of older and larger nestlings, to explain the asynchronous hatching of passerines is problematic, thus conduct of future studies focusing on other hypotheses in order to explain the asynchronous hatching of this passerine bird will be necessary.

Association between metabolic syndrome and gastric cancer risk: results from the Health Examinees Study.

BACKGROUND: Previous studies suggested that metabolic syndrome (MetS) might create a pro-cancer environment and increase cancer incidence. However, evidence on the risk of gastric cancer (GC) was limited. This study aimed to evaluate the association between MetS and its components and GC in the Korean population. METHODS: Included were 108,397 individuals who participated in the large-scale prospective cohort study, the Health Examinees-Gem study during 2004-2017. The multivariable Cox proportional was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) on the association between MetS and its components with GC risk. Age was used as the time scale in the analyses. The stratified analysis was performed to determine the joint effect of lifestyle factors and MetS on GC risk in different groups. RESULTS: During the mean follow-up of 9.1 years, 759 cases of newly diagnosed cancer (408 men and 351 women) were identified. Overall, participants with MetS had a 26% increased risk of GC than those without MetS (HR 1.26; 95% CI 1.07-1.47); the risk increased with the number of MetS components (p for trend 0.01). Hypertriglyceridemia, low HDL-cholesterol, and hyperglycemia were independently associated with the risk of GC. The potential joint effect of MetS and current smokers (p for interaction 0.02) and obesity (BMI ≥ 25.0) (p for interaction 0.03) in GC. CONCLUSIONS: In this prospective cohort study, we found that MetS were associated with an increased risk of GC in the Korean population. Our findings suggest that MetS may be a potentially modifiable risk factor for GC risk.

A framework for nationwide COVID-19 vaccine safety research in the Republic of Korea: the COVID-19 Vaccine Safety Research Committee.

With the introduction of coronavirus disease 2019 (COVID-19) vaccines, the Korea Disease Control and Prevention Agency (KDCA) commissioned the National Academy of Medicine of Korea to gather experts to independently assess post-vaccination adverse events. Accordingly, the COVID-19 Vaccine Safety Research Committee (CoVaSC) was launched in November 2021 to perform safety studies and establish evidence for policy guidance. The CoVaSC established 3 committees for epidemiology, clinical research, and communication. The CoVaSC mainly utilizes pseudonymized data linking KDCA's COVID-19 vaccination data and the National Health Insurance Service's claims data. The CoVaSC's 5-step research process involves defining the target diseases and organizing ad-hoc committees, developing research protocols, performing analyses, assessing causal relationships, and announcing research findings and utilizing them to guide compensation policies. As of 2022, the CoVaSC completed this research process for 15 adverse events. The CoVaSC launched the COVID-19 Vaccine Safety Research Center in September 2022 and has been reorganized into 4 divisions to promote research including international collaborative studies, long-/short-term follow-up studies, and education programs. Through these enhancements, the CoVaSC will continue to swiftly provide scientific evidence for COVID-19 vaccine research and compensation and may serve as a model for preparing for future epidemics of new diseases.

Soybean product consumption decreases risk of gastric cancer: results from the Health Examinees Study.

BACKGROUND: Epidemiological findings on the association between soybean product consumption and gastric cancer risk remain inconsistent. We evaluated the relationship between soybean product consumption and the risk of gastric cancer in a prospective cohort study in Korea. METHODS: This prospective cohort study included a total of 139,267 participants aged 40-69 years from the Health Examinees-Gem (HEXA-G) study between 2004 and 2013. Information on cancer diagnosis was retrieved from the Korea Central Cancer Registry until 31 December 2018. Multivariate hazard ratios (HRs) and 95% of confidence intervals (CIs) for the risk of gastric cancer according to the consumption of soybean products were estimated using Cox proportional hazards models. RESULTS: A total of 767 incident cases of gastric cancer occurred over an average follow-up period of 9.21 years. We found that men who consumed two servings per week had 37% lower risk of gastric cancer compared with who consume those who almost never consumed (HR for tofu consumption of more than two servings/week vs. almost never consumed was 0.63 (95% CI 0.45, 0.89); p for trend = 0.04). Among men with a BMI of less than 25 kg/m2, increased consumption of soybean paste (p for trend = 0.02) and tofu (HR 0.51 (95% CI 0.32, 0.82 for more than two servings/week vs. almost never consumed); p for trend = 0.01) was associated with decreased risk of gastric cancer. CONCLUSION: Our results suggest that a high consumption of soybean products has a protective effect against gastric cancer.

Associations Between Modifiable Risk Factors and Changes in Glycemic Status Among Individuals With Prediabetes.

OBJECTIVE: To examine the associations between modifiable risk factors and glycemic status changes in individuals with prediabetes. RESEARCH DESIGN AND METHODS: A total of 10,358 individuals with prediabetes defined by their fasting blood glucose and HbA1c levels from the Health Examinees-Gem study were included in the present study. Modifiable factors, including BMI, abdominal obesity, smoking status, physical activity, alcohol consumption, diet quality, hypertension, and dyslipidemia, were examined to determine their associations with changes in glycemic status during follow-up. In addition, modifiable-factor scores were calculated, and their association with changes in glycemic status was also analyzed. RESULTS: The median follow-up time for this study was 4 years (range, 1-7 years). BMI ≥25 kg/m2 (adjusted odds ratio [OR] 0.71 [95% CI 0.63-0.79]), abdominal obesity (OR 0.76 [95% CI 0.68-0.86]), heavy drinking (OR 0.74 [95% CI 0.60-0.91]), hypertension (OR 0.71 [95% CI 0.64-0.79]), and dyslipidemia (OR 0.78 [95% CI 0.70-0.85]) were associated with a lower possibility of normoglycemia reversion. BMI ≥25 kg/m2 (OR 1.58 [95% CI 1.29-1.94]), abdominal obesity (OR 1.31 [95% CI 1.11-1.55]), current smoking (OR 1.43 [95% CI 1.07-1.91]), and hypertension (OR 1.26 [95% CI 1.07-1.49]) were associated with a higher probability of type 2 diabetes progression. Having more favorable modifiable factors was also associated with normoglycemia reversion (OR 1.46 [95% CI 1.30-1.64]) and type 2 diabetes progression (OR 0.62 [95% CI 0.49-0.77]). CONCLUSIONS: More favorable modifiable factors were related to a higher probability of returning to normoglycemia and a lower probability of progression to type 2 diabetes.