The current disclosure relates to combination treatments for breast cancers such as TNBC and for prostate cancers. Embodiments concern methods, compositions, and apparatuses for treating breast cancer and prostate cancer patients. Aspects relate to a method of inhibiting proliferation of glucocorticoid receptor positive (GR+) breast or prostate cancer cells comprising administering to the cells an effective amount of a BET inhibitor in combination with one or both of a chemotherapeutic agent and a glucocorticoid receptor modulator.