1.IARC Group 1 Pharmaceuticals and Associated Cancer Risks: A Nationwide Population-Based Cohort Study in Korea
Woojin LIM ; Na Rae LEE ; Ho Gyun SHIN ; Su-Yeon YU ; Sue K. PARK
Cancer Research and Treatment 2026;58(2):376-392
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.
2.Association between working ≥10 hours per day and satisfaction with work environment among wage workers in Korea: a cross-sectional study using data from the 7th Korean Working Conditions Survey
Rae-Yun KIM ; Dong-Woo KIM ; Yoon-Soo JANG ; Na-Rae LEE ; June-Hee LEE ; Kyung-Jae LEE
Annals of Occupational and Environmental Medicine 2026;38(1):e9-
Background:
Long working hours have been associated with adverse physical and mental health outcomes; however, evidence regarding their relationship with satisfaction with work environment remains limited, particularly when long working hours are defined using a specific daily threshold. This study examined the association between working ≥10 hours per day and satisfaction with work environment among Korean wage workers, focusing on the cumulative number of such workdays per month.
Methods:
This cross-sectional study analyzed data from the 7th Korean Working Conditions Survey. A total of 24,269 wage workers aged ≥18 years were included after excluding self-employed workers, unpaid family workers, shift workers, and respondents with missing data. Working ≥10 hours per day was categorized as 0, 1–9, and ≥10 days per month. Satisfaction with work environment was categorized as satisfied or dissatisfied. Multiple logistic regression analyses were conducted to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for dissatisfaction with work environment according to the number of long working days, adjusting for demographic and occupational characteristics.
Results:
Compared with workers who did not work ≥10 hours per day, those who worked 1–9 days and ≥10 days per month showed progressively higher levels of dissatisfaction with work environment. After adjustment for demographic and occupational factors, the odds of dissatisfaction with work environment were significantly higher among workers who worked ≥10 hours per day for 1–9 days per month (OR: 1.380; 95% CI: 1.145–1.665) and ≥10 days per month (OR: 2.106; 95% CI: 1.627–2.725), demonstrating a dose–response relationship.
Conclusions
Among the analytic sample of Korean wage workers included in this study, working ≥10 hours per day was associated with greater dissatisfaction with work environment, with a dose–response pattern according to the number of long working days per month.
5.Factors Influencing Cone Contrast Sensitivity in Koreans Aged 60 Years and Older
Han Eul LEE ; Hee Seung CHIN ; Na Rae KIM ; Ji Won JUNG
Journal of the Korean Ophthalmological Society 2025;66(1):55-62
Purpose:
To examine the factors impacting cone contrast sensitivity in Koreans aged > 60 years who are scheduled for cataract surgery and do not have congenital color vision deficiencies.
Methods:
The ColorDx Cone contrast test HD® (CCT-HD; Konan Medical, Inc., CA, USA) was administered to 33 Korean individuals (33 eyes) to evaluate CCT scores before and after cataract surgery, as well as changes in CCT scores according to the degree of progression by cataract type. Correlations between CCT scores and age, best corrected visual acuity (BCVA), regional retinal thickness, and length of the photoreceptor outer segment (PROS) at the fovea were analyzed in pseudophakic eyes.
Results:
Average scores for short-, medium-, and long-wavelength cone contrast sensitivity tests (S-CCT, M-CCT, and L-CCT, respectively) improved after surgery (p = 0.010, p = 0.001, and p = 0.028, respectively). Comparing CCT score changes before and after surgery by cataract progression, higher cataract grades were associated with greater CCT score changes, though the differences were not statistically significant (p > 0.05). In pseudophakic eyes, S-CCT scores negatively correlated with age (p = 0.017). No significant correlations were found between S-CCT, M-CCT, and L-CCT scores and BCVA, whereas S-CCT, M-CCT, and L-CCT scores positively correlated with PROS at the fovea (p < 0.001).
Conclusions
Cone contrast sensitivity in individuals aged > 60 years is influenced by age and cataract status and may serve as a valuable indicator of visual function in clinical research.
6.Increased risk of adenomatous colon polyps in patients with long-term use of proton pump inhibitors: a single-center retrospective study
Journal of Yeungnam Medical Science 2025;42(1):24-
Background:
It is unclear whether long-term use of proton pump inhibitors (PPIs) has a potential carcinogenic effect on the colorectum.
Methods:
We reviewed a consecutive series of neurosurgery outpatients who underwent two or more colonoscopies between January 2014 and April 2023. Patients in whom the timing of endoscopy was not in accordance with the guidelines and those without a history of previous endoscopy were excluded. In the second colonoscopy, the risk of adenomatous colon polyps was evaluated depending on whether the patient had taken a PPI.
Results:
In total, 520 patients were enrolled. In the multivariate analysis related to the risk of adenomatous colon polyps, age and aspirin use for >5 years were identified as significant factors. After excluding patients who had taken aspirin for >5 years, the patients were divided into three groups: those who had taken PPIs for >12 months, those who had taken PPIs for >3 months but <12 months, and those who had not taken PPIs. The risk of adenomatous colon polyps in these groups was 35.2%, 32.8%, and 22.8%, respectively (p=0.10). In the post-hoc analysis, there was a significant difference between patients who took PPIs and those who did not (p=0.03). In the multivariate analysis, a history of PPI use for >12 months was a significant risk factor for the development of advanced colon polyps (p=0.03).
Conclusion
Prolonged PPI use appears to increase the risk of developing adenomatous and advanced colon polyps.
7.Factors Influencing Cone Contrast Sensitivity in Koreans Aged 60 Years and Older
Han Eul LEE ; Hee Seung CHIN ; Na Rae KIM ; Ji Won JUNG
Journal of the Korean Ophthalmological Society 2025;66(1):55-62
Purpose:
To examine the factors impacting cone contrast sensitivity in Koreans aged > 60 years who are scheduled for cataract surgery and do not have congenital color vision deficiencies.
Methods:
The ColorDx Cone contrast test HD® (CCT-HD; Konan Medical, Inc., CA, USA) was administered to 33 Korean individuals (33 eyes) to evaluate CCT scores before and after cataract surgery, as well as changes in CCT scores according to the degree of progression by cataract type. Correlations between CCT scores and age, best corrected visual acuity (BCVA), regional retinal thickness, and length of the photoreceptor outer segment (PROS) at the fovea were analyzed in pseudophakic eyes.
Results:
Average scores for short-, medium-, and long-wavelength cone contrast sensitivity tests (S-CCT, M-CCT, and L-CCT, respectively) improved after surgery (p = 0.010, p = 0.001, and p = 0.028, respectively). Comparing CCT score changes before and after surgery by cataract progression, higher cataract grades were associated with greater CCT score changes, though the differences were not statistically significant (p > 0.05). In pseudophakic eyes, S-CCT scores negatively correlated with age (p = 0.017). No significant correlations were found between S-CCT, M-CCT, and L-CCT scores and BCVA, whereas S-CCT, M-CCT, and L-CCT scores positively correlated with PROS at the fovea (p < 0.001).
Conclusions
Cone contrast sensitivity in individuals aged > 60 years is influenced by age and cataract status and may serve as a valuable indicator of visual function in clinical research.
8.Factors Influencing Cone Contrast Sensitivity in Koreans Aged 60 Years and Older
Han Eul LEE ; Hee Seung CHIN ; Na Rae KIM ; Ji Won JUNG
Journal of the Korean Ophthalmological Society 2025;66(1):55-62
Purpose:
To examine the factors impacting cone contrast sensitivity in Koreans aged > 60 years who are scheduled for cataract surgery and do not have congenital color vision deficiencies.
Methods:
The ColorDx Cone contrast test HD® (CCT-HD; Konan Medical, Inc., CA, USA) was administered to 33 Korean individuals (33 eyes) to evaluate CCT scores before and after cataract surgery, as well as changes in CCT scores according to the degree of progression by cataract type. Correlations between CCT scores and age, best corrected visual acuity (BCVA), regional retinal thickness, and length of the photoreceptor outer segment (PROS) at the fovea were analyzed in pseudophakic eyes.
Results:
Average scores for short-, medium-, and long-wavelength cone contrast sensitivity tests (S-CCT, M-CCT, and L-CCT, respectively) improved after surgery (p = 0.010, p = 0.001, and p = 0.028, respectively). Comparing CCT score changes before and after surgery by cataract progression, higher cataract grades were associated with greater CCT score changes, though the differences were not statistically significant (p > 0.05). In pseudophakic eyes, S-CCT scores negatively correlated with age (p = 0.017). No significant correlations were found between S-CCT, M-CCT, and L-CCT scores and BCVA, whereas S-CCT, M-CCT, and L-CCT scores positively correlated with PROS at the fovea (p < 0.001).
Conclusions
Cone contrast sensitivity in individuals aged > 60 years is influenced by age and cataract status and may serve as a valuable indicator of visual function in clinical research.
9.Increased risk of adenomatous colon polyps in patients with long-term use of proton pump inhibitors: a single-center retrospective study
Journal of Yeungnam Medical Science 2025;42(1):24-
Background:
It is unclear whether long-term use of proton pump inhibitors (PPIs) has a potential carcinogenic effect on the colorectum.
Methods:
We reviewed a consecutive series of neurosurgery outpatients who underwent two or more colonoscopies between January 2014 and April 2023. Patients in whom the timing of endoscopy was not in accordance with the guidelines and those without a history of previous endoscopy were excluded. In the second colonoscopy, the risk of adenomatous colon polyps was evaluated depending on whether the patient had taken a PPI.
Results:
In total, 520 patients were enrolled. In the multivariate analysis related to the risk of adenomatous colon polyps, age and aspirin use for >5 years were identified as significant factors. After excluding patients who had taken aspirin for >5 years, the patients were divided into three groups: those who had taken PPIs for >12 months, those who had taken PPIs for >3 months but <12 months, and those who had not taken PPIs. The risk of adenomatous colon polyps in these groups was 35.2%, 32.8%, and 22.8%, respectively (p=0.10). In the post-hoc analysis, there was a significant difference between patients who took PPIs and those who did not (p=0.03). In the multivariate analysis, a history of PPI use for >12 months was a significant risk factor for the development of advanced colon polyps (p=0.03).
Conclusion
Prolonged PPI use appears to increase the risk of developing adenomatous and advanced colon polyps.
10.Increased risk of adenomatous colon polyps in patients with long-term use of proton pump inhibitors: a single-center retrospective study
Journal of Yeungnam Medical Science 2025;42(1):24-
Background:
It is unclear whether long-term use of proton pump inhibitors (PPIs) has a potential carcinogenic effect on the colorectum.
Methods:
We reviewed a consecutive series of neurosurgery outpatients who underwent two or more colonoscopies between January 2014 and April 2023. Patients in whom the timing of endoscopy was not in accordance with the guidelines and those without a history of previous endoscopy were excluded. In the second colonoscopy, the risk of adenomatous colon polyps was evaluated depending on whether the patient had taken a PPI.
Results:
In total, 520 patients were enrolled. In the multivariate analysis related to the risk of adenomatous colon polyps, age and aspirin use for >5 years were identified as significant factors. After excluding patients who had taken aspirin for >5 years, the patients were divided into three groups: those who had taken PPIs for >12 months, those who had taken PPIs for >3 months but <12 months, and those who had not taken PPIs. The risk of adenomatous colon polyps in these groups was 35.2%, 32.8%, and 22.8%, respectively (p=0.10). In the post-hoc analysis, there was a significant difference between patients who took PPIs and those who did not (p=0.03). In the multivariate analysis, a history of PPI use for >12 months was a significant risk factor for the development of advanced colon polyps (p=0.03).
Conclusion
Prolonged PPI use appears to increase the risk of developing adenomatous and advanced colon polyps.

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