Purpose: The aim of this study is to summarize cancer risk among patients with clinical indications of immunosuppressive and antineoplastic drugs in Korea, which are pharmaceuticals defined as group 1 by International Agency for Research on Cancer. Materials and Methods: We conducted a nationwide population-based retrospective cohort study using the Korean National Health Insurance Service claims data from 2002 to 2018. Patients with clinical indications for group 1 pharmaceuticals from 2002 to 2017 were selected as baseline population, and followed up until 2018. Cox proportional hazards regression model was used to analyze the risk of cancer and dose-response relationship between group 1 pharmaceuticals and cancer. Results: Azathioprine use increased the risk of skin and hematologic cancer (hazard ratio [HR], 4.63; 95% confidence interval [CI], 2.91 to 7.39 and HR, 3.15; 95% CI, 2.41 to 4.13). Cyclosporine use increased the risk of skin and hematologic cancer (HR, 2.30; 95% CI, 1.79 to 2.95 and HR, 2.96; 95% CI, 2.59 to 3.40). Cyclophosphamide use increased the risk of bladder and hematologic cancer (HR, 2.69; 95% CI, 1.92 to 3.78 and HR, 3.83; 95% CI, 3.20 to 4.59). Chlorambucil use increased the risk of hematologic cancer (HR, 3.51; 95% CI, 2.53 to 4.87) and melphalan use increased the risk of hematologic cancer (HR, 16.31; 95% CI, 13.41 to 19.85). Methoxsalen use increased the risk of skin cancer (HR, 2.32; 95% CI, 1.36 to 3.95). Conclusion Group 1 pharmaceuticals were associated with increased risk of cancer. The results are expected to help establish alternative clinical strategies and policies for patients with clinical indications of group 1 pharmaceuticals, by continuous risk analysis and discussions on the surveillance systems.

suggest that some reproductive factors associated with BC differ across ethnicities and time trends, perhaps due to the prevalence of reproductive factors and the baseline hazard of BC.

School meal service workers may face an increased risk of lung cancer due to the nature of their work. This study aims to assess environmental exposure levels during occupational cooking among these workers in Seoul, Korea, and to examine the associations with carcinogen-associated biomarkers. Additionally, the study seeks to verify lung carcinogenesis through experiments using lung organoids treated with carcinogens, such as polycyclic aromatic hydrocarbons (PAHs) and particulate matter. Here, we introduce the study protocol and outline our research strategies. This etiome study employs molecular epidemiological approaches involving at least 200 school meal service workers from 25-30 school cafeterias in Seoul, as well as in vitro lung organoid experiments. The study includes a questionnaire survey to analyze workers’ occupational environments, focusing on exposure to hazardous substances such as cooking oil fumes and assessing the use of personal protective equipment (e.g., masks) and the presence of ventilation systems. We measure molecular epigenomic biomarkers, including PAH adducts and metabolites along with methylation markers, in the exposure and control groups. Additionally, lung organoid experiments are performed to investigate the potential for lung cancer development due to respiratory carcinogen exposure in cooks. This study is expected to contribute to health risk assessments and the establishment of preventive strategies for meal service workers.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

School meal service workers may face an increased risk of lung cancer due to the nature of their work. This study aims to assess environmental exposure levels during occupational cooking among these workers in Seoul, Korea, and to examine the associations with carcinogen-associated biomarkers. Additionally, the study seeks to verify lung carcinogenesis through experiments using lung organoids treated with carcinogens, such as polycyclic aromatic hydrocarbons (PAHs) and particulate matter. Here, we introduce the study protocol and outline our research strategies. This etiome study employs molecular epidemiological approaches involving at least 200 school meal service workers from 25-30 school cafeterias in Seoul, as well as in vitro lung organoid experiments. The study includes a questionnaire survey to analyze workers’ occupational environments, focusing on exposure to hazardous substances such as cooking oil fumes and assessing the use of personal protective equipment (e.g., masks) and the presence of ventilation systems. We measure molecular epigenomic biomarkers, including PAH adducts and metabolites along with methylation markers, in the exposure and control groups. Additionally, lung organoid experiments are performed to investigate the potential for lung cancer development due to respiratory carcinogen exposure in cooks. This study is expected to contribute to health risk assessments and the establishment of preventive strategies for meal service workers.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.