Association Of Breast Cancer Risk In Traditional Chinese Medicine Use In Endometriosis Patients: A Nationwide Population-Based Cohort Study

Fang-I LIAO, China Medical University Hospital, Taiwan (ROC)
LIN C. 3,4

1 Department of Traditional Chinese Medicine, China Medical University Hospital, Taichung, Taiwan, R.O.C.
2 Graduate Institute of Chinese Medicine, College of Traditional Chinese Medicine , China Medical University, Taichung, Taiwan, R.O.C.
3 Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan, R.O.C.
4 College of Medicine, China Medical University, Taichung, Taiwan, R.O.C.

Purpose: Use the National Health Insurance Research Database (NHIRD) for cohort study to evaluate the breast cancer risk in endometriosis patient with Traditional Chinese Medicine.  
Methods: We used Longitudinal Health Insurance Database (LHID) to construct the study. The LHID was a sub-database of the National Health Insurance Research Database (NHIRD) which was involved the claims data from Taiwan National Health Insurance program (Taiwan NHI). This study wanted to clarify the effect of TCM treatment for breast cancer risk in endometriosis patient. We selected the new onset endometriosis patient (ICD-9-CM 617) during from 2001 to 2009. The main outcome of the research was the developing breast cancer (ICD-9-CM 174). We terminated the follow-up when the patient withdrawn the insurance, breast cancer occurrence, or until December 31, 2011. TCM group means use TCM treatment after new onset endometriosis diagnosis, and TCM non-users group means patients did not use TCM treatment after endometriosis diagnosis. 
Results: The breast cancer incidence density for the patients with TCM visited one year ago before endometriosis diagnosis did not increase significantly (HR = 1.20, 95% CI = 0.77-1.86). The one-year post-operative TCM users group had a 2.30-fold increased risk of developing breast cancer than the TCM non-users group (HR = 2.30, 95% CI = 1.22-4.32). 
Conclusions: According to this study, association of breast cancer risk and TCM use in endometriosis patients definitely depends on  the timing of TCM intervention before or after new onset diagnosis. 
Funding source: This study is supported in part by Taiwan Ministry of Health and Welfare Clinical Trial and Research Center of Excellence (MOHW104-TDU-B-212-113002), China Medical University Hospital, Academia Sinica Taiwan Biobank Stroke Biosignature Project (BM104010092), NRPB Stroke Clinical Trial Consortium (MOST 103-2325-B-039 -006), Tseng-Lien Lin Foundation, Taichung, Taiwan, Taiwan Brain Disease Foundation, Taipei, Taiwan, and Katsuzo and Kiyo Aoshima Memorial Funds, Japan.