Periductal mastitis is a distinct benign breast condition of unknown etiology. Mass, abscess and fistula are most common manifestations of the disease. Wide surgical excision, fistulectomy and extended excision with transfer of a random breast dermo-glandular flap (BDGF) are effective surgical modalities for different type of PDM.

Drug and xenobiotic metabolizing enzymes (DXME) play important roles in drug responses and carcinogenesis. Recent studies have found that expression of DXME in cancer cells significantly affects drug clearance and the onset of drug resistance. In this study we compared the expression of DXME in breast tumor tissue samples from patients representing three ethnic groups: Caucasian Americans (CA), African Americans (AA), and Asian Americans (AS). We further combined DXME gene expression data with eQTL data from the GTEx project and with allele frequency data from the 1000 Genomes project to identify SNPs that may be associated with differential expression of DXME genes. We identified substantial differences among CA, AA, and AS populations in the expression of DXME genes and in activation of pathways involved in drug metabolism, including those involved in metabolizing chemotherapy drugs that are commonly used in the treatment of breast cancer. These data suggest that differential expression of DXME may associate with health disparities in breast cancer outcomes observed among these three ethnic groups. Our study suggests that development of personalized treatment strategies for breast cancer patients could be improved by considering both germline genotypes and tumor specific mutations and expression profiles related to DXME genes.

Background Intercellular communication is crucial for breast cancer progression and metastasis. However, the role of cancer-derived exosomes and their crucial microRNA (miRNA) cargoes mediating intercellular communication requires further investigation. Methods Cancer-derived exosomes were isolated using differential centrifugation and differentially expressed miRNAs were determined by microarrays and qRT-PCR analysis. Cell proliferation, wound-healing, Transwell invasion, and tumor xenograft assays were used for functional research. Plasma exosomal RNA was isolated to verify its role as a prognostic biomarker. Results We found that the tumor-promoting capacity of the exosomes was positively related to their cells of origin. MiR-7641 was identified to be the most differentially expressed miRNA, both at endogenous and secretory levels in high-metastatic cancer cells. MiR-7641 could promote tumor cell progression and metastasis, and that these functions of miR-7641 could alter recipient cells via transportation of exosomes. Additionally, exosomal miR-7641 could promote tumor growth in vivo; and its levels were significantly elevated in the plasma of patients with distant metastasis. Bioinformatics analysis has suggested that miR-7641 is correlated with breast cancer survival, and several important cellular and biological processes are closely targeted by miR-7641. Conclusion The findings indicate miR-7641 to be an important component of the cancer exosomes in promoting tumor progression and metastasis via intercellular communication. Additionally, exosomal miR-7641 may serve as a promising non-invasive diagnostic biomarker and potential targetable candidate in breast cancer treatment.