Chemotherapy is effective in treating invasive breast cancer. But can it also cause metastasis? Experimental studies in mice have suggested that this may be the case. In a further investigation of this matter, an international team of researchers has shown that two classes of chemotherapy drugs used in neoadjuvant (pre-operative) breast cancer therapy, taxanes and anthracyclines, cause tumors to release extracellular vesicles (EVs) such as exosomes that can enable the seeding and growth of metas...