This invention is directed to the treatment of cancers, e.g., inflammatory breast cancer, with NK (natural killer) cells wherein the cells are modified ex vivo such that their ability to overcome the chemorepellant effect of a tumor is enhanced. The cells may be genetically modified ex vivo and/or modified by contacting the cells ex vivo with an anti-chemorepellant agent. This invention also provides ex vivo modified NK cells, which are modified such that they express no or substantially no CXCR4 on their cell surface, or express CXCR7, or express a chimeric antigen receptor, or combinations thereof. The invention also relates to methods for treating a patient having a tumor, e.g., inflammatory breast cancer, by administering the modified NK cells, with or without treatment with other conventional anticancer treatments, e.g. , chemotherapy, radiotherapy, viral therapies, hormonal therapies, as well as other immunotherapies and anti-chemorepellant therapies.