Chinese Herbal Acupoint Application Combined With Triple Antiemetic Therapy for Prevention of Chemotherapy-Induced Nausea and Vomiting in Breast Cancer

The goal of this clinical trial is to learn whether Chinese herbal acupoint application, when added to standard three-drug anti-nausea treatment, can prevent nausea and vomiting caused by chemotherapy in people with breast cancer. The study will also evaluate the safety of the Chinese herbal acupoint application. The main questions it aims to answer are: * Does Chinese herbal acupoint application help participants have less nausea during the first 5 days after chemotherapy? * Does it reduce vomiting and the need for additional anti-nausea medicine? * Does it affect the impact of chemotherapy-related nausea and vomiting on daily life? * What medical problems or side effects occur with the Chinese herbal acupoint application? Researchers will compare Chinese herbal acupoint application with a sham application. Both groups will receive standard three-drug anti-nausea treatment. The sham application looks and feels similar to the herbal application but does not contain the active herbal ingredients. Participants will: * Receive one cycle of planned chemotherapy and standard three-drug anti-nausea treatment. * Receive either the Chinese herbal acupoint application or sham application before chemotherapy. The application will be placed on selected acupuncture points for 4 to 6 hours. * Record nausea, vomiting, and use of additional anti-nausea medicine during the first 5 days after chemotherapy. * Complete a questionnaire about how nausea and vomiting affect daily life. * Have safety follow-up for about 2 weeks after chemotherapy.