Genetic testing is helpful for chemotherapy after breast cancer surgery. Genetic testing is helpful for chemotherapy after surgery for breast cancer patients, and by doing genetic testing you can look for opportunities to use targeted drugs. Breast cancer patients doing genetic testing can understand the root cause of cancer. Cancer patients do not have to do genetic testing once, some need to do it several times. Postoperative chemotherapy for breast cancer can have adverse reactions, such as nausea, vomiting, loss of appetite and other digestive symptoms, and some cause hair loss and decreased resistance to disease. If the side effects of chemotherapy are relatively large, do not force chemotherapy. Breast cancer patients should actively consult the doctor, do genetic testing under the guidance of the physician’s interview, and follow the standardized treatment, patients should not self-medication to avoid adverse results.