Comparison of tumor recurrence after resection of highly- and poorly-metastatic triple-negative breast cancer in orthotopic nude-mouse models

Background: Triple-negative breast cancer (TNBC), defined by the absence of receptors for estrogen, progesterone and human epithelial receptor 2, is a recalcitrant disease in need of effective therapy. We previously isolated highly-metastatic variants of the human TNBC cell line MDA-MB-231 using serial orthotopic implantation in nude mice. Materials and Methods: In the present report, we compared local and metastatic recurrence in lymph nodes in orthotopic nude-mouse models after bright-light surgery (BLS) of tumors from highly-metastatic variants or poorly-metastatic parental MDA-MB-231-RFP cells. Orthotopic tumors from parental MDA-MB-231 or highly-metastatic MDA-MB-231 were resected under bright light similar to an operating room. Results: After resection of primary tumors, local recurrence from highly-metastatic MDA-MB-231 cells grew more rapidly than did parental MDA-MB-231 cells. Lymph-node metastasis from highlymetastatic MDA-MB-231 cells occurred after primary tumor resection much more extensively than after parental MDAMB-231 tumors were resected. Conclusion: The results of the present report suggest that conventional surgery under bright light was unable to control highly-metastatic compared with poorly-metastatic MDA-MB-231 TNBC.