Cancer Research and Treatment

General

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 Res Treat. 2026;58(2):376-392. Published online April 24, 2025; DOI: https://doi.org/10.4143/crt.2024.1201

Abstract PDF Supplementary Material PubReader ePub: 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.

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Estimation of Population Attributable Fraction by Hormone and Reproductive Factors on Female Cancer in the Republic of Korea, 2015 to 2030: Youjin Hong, Soseul Sung, Woojin Lim, Sungji Moon, Kwang-Pil Ko, Jung Eun Lee, Inah Kim, Sun Ha Jee, Sun-Seog Kweon, Min-Ho Shin, Sangmin Park, Seung-Ho Ryu, Sun Young Yang, Jeongseon Kim, Sang-Wook Yi, Yoon-Jung Choi, Jeong-Soo Im, Hong Gwan Seo, Sue K. Park; Cancer Res Treat. 2025;57(3):649-658. Published online November 19, 2024; DOI: https://doi.org/10.4143/crt.2024.707

Abstract PDF Supplementary Material PubReader ePub

Purpose
Population attributable fractions (PAFs) for hormone and reproductive factors have been estimated in several countries. International Agency for Research on Cancer (IARC) designated as group 1 and group 2A carcinogen for hormone factors in breast, ovarian, endometrial and uterine cervix cancer. This study aimed to estimate the PAFs of hormone/reproductive factor attributed to cancer incidence and deaths in Korean women and projected trends from 2015 to 2030.
Materials and Methods
The PAF was estimated with using the 2005 standardized prevalence rates and 2020 incidence and deaths with a 15-year latency. Based on the Levin’s formula, prevalence rates were calculated using the Korea National Health and Nutrition Examination Survey (KNHANES) and the relative risks, which were the risk of selected female cancer associated with oral contraceptive, hormone replacement therapy and duration of breastfeeding, were estimated from the meta-analysis of studies performed in Korean women population. Studies based on the Asian and Global populations were calculated as a sensitivity analysis.
Results
The estimation PAFs for hormone was 1.02% with 1,192 cases and reproductive was 2.67% with 3,112 cases. Moreover, 0.40% (125 deaths) and 1.09% (342 deaths) in female-related cancer deaths in order. Estrogen-progesterone combined hormone replacement therapy (HRT) accounted the most proportion in hormone factors and breastfeeding in reproductive factors. Also, the breast cancer had the highest percent in both hormone and reproductive factors.
Conclusion
Through this study, 1.02% and 2.67% of female-related cancer incidence will be reduced by encouraging avoiding the use of oral contraceptives and HRT and breastfeeding for more than 6 months in reproductive factors. Additionally, among four selected female cancers in this study, breast cancer was observed to be a significant level of prevention.

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Application and interpretation of attributable fraction measures from clinical practice to policy: a narrative review
Sue Kyung Park
Journal of the Korean Medical Association.2026; 69(5): 411. CrossRef
Fraction of cancer incidence and mortality attributable to dietary factors in Korea from 2015 to 2030
Hyun Jeong Cho, Jin Young Yoo, Ga-Eun Yie, An Na Kim, Soseul Sung, Sungji Moon, Youjin Hong, Sangjun Lee, Inah Kim, Kwang-Pil Ko, Sun-Seog Kweon, Jung Eun Lee, Sue K. Park
Epidemiology and Health.2025; 47: e2025065. CrossRef

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Fraction of Cancer Attributable to Carcinogenic Drugs in Korea from 2015 to 2030: Woojin Lim, Soseul Sung, Youjin Hong, Sungji Moon, Sangjun Lee, Kyungsik Kim, Jung Eun Lee, Inah Kim, Kwang-Pil Ko, Sue K. Park; Cancer Res Treat. 2025;57(3):635-648. Published online November 6, 2024; DOI: https://doi.org/10.4143/crt.2024.644

Abstract PDF Supplementary Material PubReader ePub

Purpose
This study aims to estimate and project the population attributable fraction (PAF) of cancer incidence and death due to carcinogenic drug use in Korea from 2015 to 2030, to estimate the degree of cancer prevention from exposure to carcinogenic drugs in Korea. Selected carcinogenic drugs were immunosuppressive and antineoplastic drugs classified as group I by the International Agency for Research on Cancer.
Materials and Methods
Systematic review and meta-analyses were conducted to estimate the relative risk of cancer associated with carcinogenic drug use. Age was standardized using the annual prevalence rate of the National Health Insurance Service sample cohort (NHIS-NSC) from 2002 to 2013 to calculate the standardized prevalence rate of carcinogenic drug use each year. The PAF of specific cancer incidence and death were calculated using Levin’s formula and Monte Carlo methods. The prevalence rates were extrapolated to estimate the trend of PAF from 2015 to 2030.
Results
In 2015, carcinogenic drugs attributed to 0.003% and 0.002% among the causes of cancer incidence and death in Korea. However, carcinogenic drugs attributed to 1.1% among the causes of both cancer incidence and death in patients with clinical indications of carcinogenic drugs.
Conclusion
The PAF in patients with clinical indications of carcinogenic drugs were significantly high and expected to increase rapidly over time. Since these drugs are listed as essential by the World Health Organization, and may be difficult to replace, a surveillance system on susceptible populations using group I carcinogenic drugs must be discussed and implemented.

Citations

Citations to this article as recorded by

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. CrossRef
Application and interpretation of attributable fraction measures from clinical practice to policy: a narrative review
Sue Kyung Park
Journal of the Korean Medical Association.2026; 69(5): 411. CrossRef
Fraction of cancer incidence and mortality attributable to dietary factors in Korea from 2015 to 2030
Hyun Jeong Cho, Jin Young Yoo, Ga-Eun Yie, An Na Kim, Soseul Sung, Sungji Moon, Youjin Hong, Sangjun Lee, Inah Kim, Kwang-Pil Ko, Sun-Seog Kweon, Jung Eun Lee, Sue K. Park
Epidemiology and Health.2025; 47: e2025065. CrossRef

5,907 View
208 Download
2 Web of Science
3 Crossref

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