Objective: To assess expressions of cIAP1, XIAP and caspase-3 in breast cancer tissue and their relations with clinicopathologic factors and prognosis.  
Methods: The protein expressions of cIAP1, XIAP and caspase-3 in 99 specimens of breast cancer tissue, 10 specimens of breast fibroadenoma tissue and 6 specimens of tumor-adjacent normal mammary tissue were determined by immunohistochemical staining. The relations of the 3 proteins with clinicopathologic features and prognosis of breast cancer patients were analyzed, by combination with the data of breast cancer patients in Kaplan-Meier Plotter database.
Results: The results of immunohistochemical staining showed that the expression levels of cIAP1, XIAP and caspase-3 protein in breast cancer tissue were all significantly higher than those in normal mammary tissue (all P<0.05), while no significant differences were noted in the expression levels of the 3 proteins between breast cancer tissue and breast adenofibroma tissue, and between breast cancer tissues from patients undergoing and not undergoing neoadjuvant chemotherapy (all P>0.05). The expression of cIAP1 was significantly associated with the menstrual status and age of patients, and the expression of XIAP was significantly related to the expression intensity of Ki-67 (all P<0.05). The results of Kaplan-Meier Plotter database analysis showed that the cIAP1 expression level exerted no significant influence on the relapse-free survival (RFS) time of breast cancer patients (P>0.05), while the RFS time in breast cancer patients with high XIAP expression level was longer than that in breast cancer patients with high XIAP expression level, and in patients with high caspase-3 expression level was shorter than that in those with low caspase-3 expression level (both P<0.05). 
Conclusion: The expressions of cIAP1, XIAP and caspase-3 may be closely related to the occurrence and development of breast cancer, and XIAP and caspase-3 may potentially be prognostic indicators for breast cancer.