What do ER(-), PR(-), and CerdB2(-) mean? ER means estrogen receptor, PR means progesterone receptor, and CerdB2 is the protein expression of an oncogene. All three are negative, and this condition is called triple negative breast cancer. This type of breast cancer is meaningless for endocrine therapy, which means it is non-hormone-dependent breast cancer and the only option is chemotherapy. In the case of CerbB2 negative, the monoclonal antibody specific to the expression of this gene, namely Herceptin, is not an option. That is, there are fewer treatment options and means available. Of course the stage of breast cancer is the most important, if it is early stage, the treatment effect is good, if it is late stage the relative treatment effect is poorer.