Breast cancer genetic testing mainly detects 21 and 70, and the need for chemotherapy also depends on the patient’s specific situation. Generally, patients with high risk of 21 gene test and those with poor prognosis of 70 gene test need chemotherapy. 1. Breast cancer 21 gene test: estrogen receptor positive and lymph node negative patients can be guided to chemotherapy treatment by 21 gene test, and current research shows that low-risk patients need to consider endocrine therapy alone for better results, and high-risk patients can get obvious treatment effect by chemotherapy. Her-2 positive postoperative breast cancer patients generally need chemotherapy, and generally no longer need to assess whether chemotherapy through the 21 gene test results. 2. Breast cancer 70 gene test: 70 gene has good predictive value for breast cancer long-term disease development, the survival rate of the group with good prognosis is higher than that of the group with bad prognosis, which can be used to guide the adjuvant treatment of breast cancer patients, and the group with bad prognosis can be treated with chemotherapy to improve the survival rate. Whether chemotherapy is needed after breast cancer genetic testing needs to be analyzed according to the results of the test, and a treatment plan that meets the patient’s own situation should be formulated for the patient.