Distribution of dyslipidemia in Chinese early breast cancer patients at diagnosis and comparison of dyslipidemia incidence following different endocrine therapies: a population-based cohort study

Background: Dyslipidemia increases the risk of cardiovascular disease death in breast cancer (BC). Based on the large West China Hospital (WCH) BC cohort, we aimed to clarify dyslipidemia prevalence at diagnosis and compare the risk of dyslipidemia induced by different endocrine and menopause status. Methods 5917 EBC female patients recorded in WCH BC cohort, diagnosed between 2008.10 and 2017.04, were included for baseline analysis. 1883 patients receiving endocrine therapy (selective estrogen receptor modulator (SERM) or aromatase inhibitor (AI), with or without ovarian function suppression) with initial normal blood lipids were included for comparison study. Dyslipidemia was defined as abnormality of cholesterol/LDL/ HDL/triglyceride. Risk accumulation function was used to calculate the incidence of dyslipidemia to assess absolute risk, and the multivariate COX regression model was used to calculate the relative risk of dyslipidemia between groups. Results 16.5% of EBC patients had dyslipidemia at diagnosis. Among EBC patients receiving endocrine therapy, the accumulated incidence of dyslipidemia within 5 years in menopausal patients was higher than that in premenopausal patients (Adjusted HR [95%CI], 1.29 [1.04–1.59], 42.6 % vs 32.6%, P = 0.0186). In premenopausal patients, the risk of abnormal TC in OFS + AI group was significantly higher than SERM group (adjusted HR, 3.50 [ 1.74–7.02], P < 0.001, 5-year abnormal rate 22.0% vs 3.5%), and that of abnormal LDL-C was also increased(adjusted HR, 6.71 [ 3.16–14.26], P < 0.001, 5-year abnormal rate 12.2% vs 1.4%). In menopausal patients, the risk of abnormal TC or LDL-C showed the similar trend in AI group compared to SERM group. Conclusions Dyslipidemia is common concomitant disease in Chinese BC patients and needs to be closely monitored. Irrespective of menopause, AIs treatment causes higher risk of TC/LDL-C dyslipidemia than SERM.