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.

Inclusion Criteria: * Age ≥18 years, regardless of sex； * Pathologically confirmed operable breast cancer with no prior systemic chemotherapy； * Planned to receive one of the following highly emetogenic chemotherapy (HEC) regimens. HEC refers to chemotherapy regimens associated with an expected incidence of vomiting of \>90% in the absence of prophylactic antiemetic treatment, including anthracycline/cyclophosphamide-based regimens (AC, TC, or EC) and carboplatin-containing regimens (e.g., TCbH, TCbHP)； * Planned to receive triple antiemetic prophylaxis consisting of an NK-1 receptor antagonist, a 5-HT3 receptor antagonist, and dexamethasone. NK-1 receptor antagonists may include fosrolapitant, aprepitant, fosaprepitant, or other approved agents; 5-HT3 receptor antagonists may include palonosetron, ondansetron, or other approved agents； * Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0-1 * Considered by the treating physician to be physically able to undergo and comply with the acupoint application procedure； * Adequate major organ function and bone marrow function。 Exclusion Criteria: * Skin damage, ulceration, scarring, or severe infection at the intended application sites; * Known history of severe allergy to any adhesive tape, patch materials, or herbal/other ingredients used in the study; * Significant nausea (VAS ≥25 mm) within 24 hours before chemotherapy that, in the investigator's judgment, is not related to chemotherapy; * Refractory vomiting due to non-chemotherapy-related causes, such as complete intestinal obstruction or severe vomiting caused by increased intracranial pressure secondary to brain metastases; * Pregnancy or breastfeeding; * Concomitant brain metastases, increased intracranial pressure, gastrointestinal obstruction, or other diseases that may cause nausea or vomiting; * Severe hepatic, renal, or cardiac dysfunction, or other serious underlying diseases that, in the investigator's judgment, make the participant unsuitable for the study; * Planned abdominal or pelvic radiotherapy within 7 days before randomization or during Days 1-7 of chemotherapy; * Use of antiemetic medications within 48 hours before chemotherapy, except for the routine prophylactic antiemetic regimen specified in the triple antiemetic therapy, or use of other medications that may affect the assessment of nausea or vomiting; * Severe psychiatric illness or cognitive impairment that prevents the participant from understanding the nausea/vomiting assessment scales or - complying with the 4-6-hour acupoint application procedure; * Inability to take oral medications; * Any other condition that, in the investigator's judgment, makes the participant unsuitable for participation in the study.