Population-based cohort study on the risk of malignancy in East Asian children with Juvenile idiopathic arthritis
1 Population-Health and Clinical Informatics Research Group, Department of Biomedical Informatics, Asia University Taiwan, Taichung, Taiwan
2 Division of Medical Oncology, Department of Internal Medicine, Kuang Tien General Hospital, Taichung, Taiwan
3 Department of Computer Science and Information Engineering, National Central University, Chungli, Taiwan
4 Division of Paediatric Allergy Asthma and Rheumatology, Department of Paediatrics, Chang Gung Memorial Hospital, Linkou, Taiwan
5 Chang Gung University College of Medicine, Taoyuan, Taiwan
6 Department of Information Management, Hsing Wu University, New Taipei City, Taiwan
BMC Cancer 2014, 14:634 doi:10.1186/1471-2407-14-634Published: 29 August 2014
To investigate the association and magnitude of risk between JIA, its associated treatment and cancer development in Taiwanese children.
Nationwide population-based 1:4 age- and gender-matched retrospective cohort study was designed using the National Health Insurance Research Database of Taiwan. A cohort of 2,892 children <16 years old with JIA was formed as well as a non-JIA cohort of 11,568 in year 2003 to 2005. They were followed up till a diagnosis of malignancy or up to 8 years until 2010. Relative risk (RR), incidence rate ratio (IRR), and adjusted hazard ratio (aHR) of developing malignancy were calculated.
The female to male ratio was 0.79:1. There were 3 cases of incident cancer in the “MTX use, biologics-naïve” group, only 1 in the anti-TNF biologics-containing group and 29 in the “both MTX- and biologics-naïve” group, in comparison, there were 50 cases of cancer in the non-JIA comparator group. During a 16114.16 patient-years follow-up, the RR and IRR for developing a malignancy in both methotrexate- and anti-tumor necrosis factor (TNF) biologics-naïve JIA children were 2.75 (95% confidence interval, 1.75 – 4.32) and 3.21 (2.01 – 5.05), respectively. For leukemia, the IRR was 7.38 (2.50 – 22.75); lymphoma, 8.30 (1.23 – 69.79); and soft tissue sarcoma, 11.07 (0.84 – 326.4). The IRR of other cancers was 2.08 (1.11 – 3.71). The aHR on cancer risk was 3.14 (1.98 – 4.98) in methotrexate- and biologics-naïve group. There were no statistically significant increased risk in JIA patients treated with methotrexate and/or anti-TNF biologics.
Compared with children without JIA, children with JIA have 3-fold increase of risk on malignancy in East Asia. Seemingly neither methotrexate nor anti-TNF biologics increases the risk further.