This study looks at how electroacupuncture (using small electric currents with needles) can help stop nausea and vomiting caused by strong chemotherapy in breast cancer patients. Participants will receive a mix of medicines, like Olanzapine (a medicine often used for mental disorders), and others to help with sickness. Patients will be split into two groups. Some will get real electroacupuncture, and others will get fake (sham) acupuncture to compare results. The study will also check if our genes affect how well this treatment works by using blood samples.

• Participation includes taking medicines and possibly getting electroacupuncture during chemotherapy.
• Patients will record any nausea or vomiting and will have blood tests.
• This study is for breast cancer patients starting strong chemotherapy.

Participants must be 18-75 years old and in good health, with a life expectancy of at least 3 months. Those with ongoing nausea, certain diseases, or who have had recent acupuncture or radiation therapy cannot join. Pregnant or breastfeeding women are also not eligible. This trial requires written consent from participants.