Breast cancer can be classiifed into 4 intrinsic subtypes by gene expression proifling: basal-like, HER-2-positive, Luminal A and Luminal B. Although Luminal cancers share similarities, the studies showed that Lu-minal A and B breast cancers should be perceived as distinct entities. Luminal B breast cancer has lower expression of hormone receptors, and it also exhibits worse prognosis and has a distinct proifle of response to chemotherapy and en-docrine therapy. This review presented the available clinical evidence for chemotherapy and endocrine therapy patterns of response, and potential targets for treatment.

The hypoxia-inducible factor-1(HIF-1) gene located on the long (q)arm 21-24 of chromosome 14, is composed of HIF-1? and HIF-1? subunits. HIF-1 promotes its target gene HRE to transcribe by binding to the element and then causes a series of responses of the cell to hypoxia. HIF-1 has been found to be overexpressed in breast cancer cell, and the expressions of HIF-1 level were correlated with the prognosis and prediction factors of breast cancer. As a cytokine, HIF-1 will be a new prognosis factor and a new target for the treatment of breast cancer.

FOXO3a is an important member of the forkhead box family. The expression of FOXO3a is correlated with cell transformation, tumor development and angiogenesis. FOXO3a inhibited tumor cell growth and progression through upregulation of the expression of Bim, p27Kip1 and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). The activation of FOXO3a is modulated by Akt, I?K? and oxidative stress. It has been demonstrated that FOXO3a was closely related to some generally accepted prognostic factors. Therefore, FOXO3a may become a new prognostic factor of breast cancer. This review focused on the structure of FOXO3a, the role of FOXO3a expression on breast cancer and the relationship between FOXO3a and the generally accepted prognostic factor of breast cancer.

Objective:To investigate the impact of polysomy 17 of breast cancer on testing results of human epidermal growth factor receptor 2 (HER2) and its clinicopathologic significance. Methods:Seventy-one patients with primary invasive breast carcinoma were studied. The HER2 gene and chromosome 17 copy numbers were determined by dual-color fluorescence in situ hybridization (FISH). The testing results were expressed by absolute HER2 gene copy number or the ratio of HER2 to chromosome 17. Based on the FISH testing results and HER2 protein expression determined by immunohistochemistry the results were compared between different groups divided by related clinicopathologic parameters.Results:All patients who had doubtable FISH results, either by absolute HER2 copy number (14 of 71 patients; 19.7%) or by the ratio HER2/chromosome 17 (2 of 71 patients, 2.8%), displayed polysomy 17. Polysomy 17-positive patients had no significant difference with HER2-negative patients in tumor grade, lymph node metastasis, and estrogen receptor (ER) expression (all P>0.05); but compared with HER2-positive patients, they showed lower tumor grade (50.0% vs 81.5%, P=0.025), higher rate of negative lymph node (55.6% vs 25.9%, P=0.045), and higher rate of ER positive expression (83.3% vs 41.7%, P=0.005) and progesterone receptor(PR)positive expression (87.5% vs 44.4%, P=0.003).Conclusion:Compared with HER2 gene amplification group, polysomy 17-positive group tends to have negative HER2 gene expression. Polysomy 17 influences the testing results of HER2 and may be the main factor that caused doubtable results in FISH examination.