Effects of everolimus combined with letrozole on MIR-429 and ZEB1 in breast cancer

Objective: To investigate the effect of everolimus combined with letrozole on MIR-429 and Zinc finger E-box binding homeobox 1 (ZEB1) in patients with breast cancer. Methods: A total of 159 patients with breast cancer were enrolled, of which 89 patients received everolimus combined with letrozole and were included as the study group (SG). Another 70 patients who received everolimus monotherapy were assigned to the control group (CG). The clinical efficacy and adverse reactions were compared. MIR-429 and ZEB1 before treatment (TO), one week of treatment (T1), two weeks of treatment (T2), three weeks of treatment (T3), four weeks of treatment (T4), and their relationship with treatment time were analyzed. ROC curve was used to analyze the predictive performance of miR-429 and ZEB1 for efficacy. Results: The SG showed significantly increased response rate compared with the CG (P=0.025). miR-429 and ZEB1 did not differ at TO and T1 (P>0.05), but were lower at T2, T3 and T4 in the SG than in the CG (P<0.001). The levels of miR-429 and ZEB1 of the two groups were the highest at TO, decreased at T1, and were the lowest at T4 (P<0.001). Spearman analysis showed that miR-429 and ZEB1 in the SG were negatively correlated with treatment time (P<0.001). From the results of ROC curve analysis, we observed that the combined detection of miR-429 and ZEB1 has excellent predictive performance for treatment efficacy (P<0.001). Conclusion: Everolimus combined with letrozole is superior to monotherapy for breast cancer, while miR-429, ZEB1 may be potential indicators for the diagnosis and treatment efficacy of breast cancer.