The purpose of this study is to examine the effect, mediators and predictors of treatment response of acupuncture in treating the psychoneurological symptom cluster (pain, fatigue, sleep disturbance) among breast cancer survivors.

Aim 1: compared to sham acupuncture and UC, determine the effect of acupuncture on a) the psychoneurological cluster (primary outcome) and b) pain, fatigue, and sleep disturbance as individual symptoms (secondary outcomes).

Aim 2: examine the role of methylsulfonylmethane as mediator in the mechanisms of acupuncture on the psychoneurological cluster and each individual symptom from week 0 to week 6 (primary endpoint) and to week 12 (secondary endpoint).

Aim 3: identify multilevel predictors of treatment response in the acupuncture group, including a) biological (metabolomic signature, age); 2) clinical (previous treatment) and 3) psychosocial (treatment expectancy) characteristics.

Inclusion Criteria:

(1) ≥ 18 years of age;(2) with histologically confirmed Stage 0-III ER/PR-positive HER2-negative breast cancer; who (3) are currently receiving adjuvant endocrine therapy; (4) completed their primary cancer treatment (e.g., surgery, radiotherapy, chemotherapy) at least 3 months prior to recruitment; (5) are acupuncture-naïve, and (6) have self- reported pain, fatigue, and sleep disturbance in the last month with an average severity rating ≥ 3 (0-10 numeric rating scale) for at least 2 of the 3 symptoms.

Exclusion Criteria:

(1) taking methylsulfonylmethane or glutathione supplements; (2) are physically or cognitively unable to complete the study procedures; (3) are pregnant.