Abstract: A method of diagnosing breast cancer is disclosed. The method comprises lysing extracellular vesicles of a subject to generate a composition comprising components of extracellular vesicles; measuring the amount of MEK1 in the composition; and diagnosing the subject with breast cancer when a level of said MEK1 in said composition is above a predetermined threshold. Kits for breast cancer diagnosis are also disclosed.

Abstract: The present invention provides an in vitro method of detecting circulating tumour cells, circulating tumour cells of epithelial phenotype and circulating tumour cells of epithelial to mesenchymal transition (EMTs), in a biological sample using, as an indicator, expression levels of miRNA-21, and obtaining a result of the method by comparing the expression levels of said miRNA-21 with a negative control or with a positive control, wherein if the expression levels in the cells of the biological sample are over-expressed in comparison to a negative control is indicative of the presence of circulating tumour cells in said biological sample or wherein if the expression levels in the cells of the biological sample are expressed in an amount greater than ? of the maximum expression achieved in a positive control is indicative of the presence of circulating tumour cells in said biological sample.

Abstract: The inventors of the present invention have surprisingly discovered that EGFR expression in nonmetastatic breast cancer patients with CK-negative CTCs could induce EMT process. A simultaneous detection of both EGFR and EMT markers (VIM and Slug) in CTCs might improve prognostic or predictive information in patients with operable breast cancer.