Assessment of Brain Cognitive Impairment in Breast Cancer

Inclusion Criteria: * Patients with primary stage I-II breast cancer. * Premenopausal women (menopausal status determined by National Comprehensive Cancer Network Breast Cancer Guidelines criteria). * No treatment other than surgery has been started (if neoadjuvant chemotherapy is required before surgery, enroll before chemotherapy starts). * Eastern Cooperative Oncology Group score of 0-1 points. * Can understand and complete various scales. * Right handedness. * Female subjects of childbearing potential must be willing to use a medically-approved high-efficiency contraceptive method (eg, intra-uterine device, birth control pill, or condom) for the duration of the study. * Sign the informed consent and voluntarily participate in this clinical observation. Exclusion Criteria: * Central nervous system (CNS) disease, history of malignancy, chronic loss of consciousness, head trauma, and any disease affecting cognitive function. * Current or former epilepsy, dementia, or learning disabilities. * Past psychiatric history. * Past history of malignancy. * MRI related contraindications: pacemakers, defibrillators, hearing aids, insulin pumps, drug dose control devices and other metal implants; patients with severe hyperthermia; patients with claustrophobia.