Effectiveness of Acupuncture for Cyclical Mastalgia （CM）

Sample size Sample size estimation was based on changes in the breast pain VAS(VAS-BP) score. According to the pre-trial, the VAS-BP score significantly decreased by 2.98 ±0.95 in MA group compared to 2.35 ±0.97 in the SM group after treatment from baseline. In the current trial, the investigators assume a significance level α = 0.05 and power (1-β) = 0.90, and providing for a two-sided outcome, at least 42 participants will be required for each group, as calculated by PASS version 11.0 (NCSS, LLC. Kaysville, UT, USA), assuming a two-tailed test with a 20% drop-out rate, a total of 108 patients (54 in each group) will be recruited.

Recruitment Patients are planned to be recruited via outpatient clinic, advertisements on websites and posters from hospitals and a chat group using WeChat (WeChat, Version: 8.0.21, Tencent, Shenzhen, China). Meanwhile, the investigators will cooperate with the gynecology and physical examination departments of the hospital for potential patients to ensure the target sample size is reached. All potentially eligible women with CM will be invited to the trial and be able to contact the researchers with the provided phone number. Patients who meet the inclusion criteria will be introduced to the study in detail and informed about the potential benefits and possible risks of this study, and will sign informed consent agreements.Then personal information including age, marriage, menstrual, and medical history and a series of questionnaire, ultrasound of breast, as recommended by SOGC guideline are cautiously recorded.

Data collection and management Plans for assessment and collection of outcomes The data will be collected using CRF. Questionnaires will be conducted by evaluators. The ultrasound image acquisition tests are performed by the ultrasound physicians. All data obtained during the study will be input into the database and anonymized and stored in the study folder. Only the research team has access to this particular research folder.

Plans to promote participant retention and complete follow-up The patients will receive sufficient information about the study and requirements during the recruitment. All patients will be reminded throughout the study to fill out the questionnaires during study visits.Throughout the follow-up period, the researchers will collect data and contact patients for completion. Patients are allowed to discontinue the study, the data collected up to the withdrawal date will be anonymized and used.

Data management The clinical trial management platform ResMan will be used to manage the data. Repeated input methods will be used to ensure that the entered data is correct. The database will be locked with a password, which will only be known by relevant personnel.