TOPO II 1% in breast cancer indicates insensitivity to chemotherapeutic agents such as anthracyclines. TOPO II is actually considered an immunohistochemical aspect, and the full set of 7 prognostic markers for drug resistance in breast cancer are P-gp, GSTĪ, TOPO II, Ki-67, ER, PR, and HER2, which have a guiding role in breast cancer prognosis. Among them, the higher the positivity of topoisomerase II (TOPO II), the more effective it is for the following drugs: chemotherapeutic drugs such as anthracyclines. (e.g., VP-16, teniposide, rose bengal, neomycin, zorubicin, epothilone, adriamycin, VM26) Higher positivity is especially effective for VP-16. In fact, the main clinical concerns are ER, PR and HER2: ER, estrogen receptor, and PR, progesterone receptor; the higher the positivity rate of both, the more effective the tumor is for endocrine therapy and the better the prognosis. However, a high rate of HER2 positivity means that the tumor is sensitive to targeted therapy. It is recommended to combine the other data in the report, follow the doctor’s instructions to receive the appropriate treatment program for the individual, active treatment, and maintain confidence.