Objective:To investigate the expression and clinical pathological significance of long noncoding RNA(LncRNA)MCM3AP-AS1 in breast cancer patients. Methods:A total of 64 cases of tumor tissue puncture specimens were collected from elderly women(age≥60)with advanced breast cancer. The expression of LncRNA MCM3AP-AS1 in tumor tissues of these patients was detected by qRT-PCR. The expressions of ER,PR,Her-2,Ki-67 and Dkk1 protein in breast cancer tissue samples were detected by immunohistochemistry. Samples with immunohistochemical Her-2 2+ were further tested by FISH. Furthermore,we analyzed the relationship between LncRNA MCM3AP-AS1 expression and clinical pathology of breast cancer patients and its impact on prognosis. Results:The expression of LncRNA MCM3AP-AS1 was significantly increased in breast cancer patients with poor tissue differentiation and ER(-),PR(-)(P < 0.01). The expression of LncRNA MCM3AP-AS1 was not associated with the presence of liver,lung or brain metastasis,but was closely related to bone metastasis(P < 0.01). Patients with ER(-),PR(-),Her-2(+) or Dkk1(+)were more likely to have bone metastases(P < 0.01). The progression-free survival of breast cancer patients with high expression of LncRNA MCM3AP-AS1 was significantly shorter than that of low expression group(P < 0.01). Conclusion:LncRNA MCM3AP-AS1 is closely related to the malignant biological behavior of female breast cancer. The detection of LncRNA MCM3AP-AS1 expression has potential value in helping us to better understand the mechanism of breast cancer and judging the prognosis of breast cancer patients.