Tamoxifen Treatment and the Reduced Risk of Hyperlipidemia in Asian Patients With Breast Cancer: A Population-Based Cohort Study.
OBJECTIVE
The association between tamoxifen (TMX) treatment and the risk of developing hyperlipidemia remains unclear.


METHODS
The records of 41,726 patients with breast cancer (28,266 received TMX and 13,460 did not) were obtained from the Taiwan National Health Insurance Research Database for the period from January 2000 to December 2008. Three-fold women without breast cancer were the control group (N = 125, 178). The main end point was developing hyperlipidemia during the follow-up.


RESULTS
During a mean follow-up of 9 years, the patients with breast cancer demonstrated a rate of developing hyperlipidemia that was 6% less (adjusted hazard ratio [HR], 0.94; 95% confidence interval [CI], 0.90-0.97) than that of the control participants without breast cancer. Stratification by age group indicated that only women aged ≥ 55 years who were diagnosed with breast cancer exhibited a significantly reduced risk of hyperlipidemia compared with the control group. With the use of 2 types of adjusted models, we observed that the TMX users (aged ≥ 55 years) consistently exhibited a significantly lower risk of hyperlipidemia than the non-TMX users and control participants (adjusted HRs, 0.79 and 0.82 from models 1 and 2, respectively). Within the 8-year follow-up period, patients with breast cancer and 366 to 1500 days of TMX therapy and > 1500 days of TMX therapy had significantly lower risks of hyperlipidemia compared with patients with ≤ 365 days of TMX therapy (adjusted HR, 0.54; 95% CI, 0.50-0.59; adjusted HR, 0.21; 95% CI, 0.18-0.24, respectively).


CONCLUSIONS
In Asian patients with breast cancer, TMX use was associated with reduced risks of hyperlipidemia.
Department of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan; Department of Emergency, Toxicology Center, China Medical University Hospital, Taichung, Taiwan.
Yun-Ping
YP
Lim
Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan; College of Medicine, China Medical University, Taichung, Taiwan.
Cheng-Li
CL
Lin
Department of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan.
Yen-Ning
YN
Lin
Department of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan.
Wei-Chih
WC
Ma
Department of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan; Department of Emergency, Toxicology Center, China Medical University Hospital, Taichung, Taiwan.
Dong-Zong
DZ
Hung
Graduate Institute of Clinical Medical Science and School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan; Department of Nuclear Medicine and PET Center, China Medical University Hospital, Taichung, Taiwan. Electronic address: d10040@mail.cmuh.org.tw.
Chia-Hung
CH
Kao
D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People; D001943:Breast Neoplasms / Q000188:drug therapy*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000453:epidemiology*; D015994:Incidence; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D020845:Selective Estrogen Receptor Modulators / Q000627:therapeutic use*; D013624:Taiwan / Q000453:epidemiology; D013629:Tamoxifen / Q000627:therapeutic use*; D055815:Young Adult
D020845:Selective Estrogen Receptor Modulators; D013629:Tamoxifen
Breast cancer; Hyperlipidemia; Population-based cohort study; Taiwan National Health Insurance Research Database; Tamoxifen