Research purpose: Lymphedema is a very common complication in breast cancer patients. However, since there is currently no curable treatment, it is important to prevent and reduce the severity of lymphedema. The purpose of this study is to evaluate whether preoperative exercise is effective in preventing lymphedema after surgery. For secondary outcome, the preventive effects of exercise on other upper extremity dysfunctions (eg. pectoralis tightness, Axillary web syndrome, Adhesive capsulitis), which are common in breast cancer patients, were assessed.

Study subjects:

• Patients aged 20 or older who were first diagnosed with breast cancer
• Patients scheduled to undergo neoadjuvant chemotherapy before surgery Study design: Prospective randomized controlled comparative clinical study
• Intervention is performed for at least 3 months during the neoadjuvant chemotherapy period before surgery.
• Treatment group: Individually tailored exercise consisting of aerobic, strength, and flexibility exercises is prescribed, self-exercise compliance monitoring through an application, and diet management education through nutritional counseling.
• Control group: One session of flexibility exercise training, diet management education through nutritional counseling

Result variable:

• Primary outcome variable:

  1) Incidence and severity of postoperative lymphedema: bilateral upper limb volume, ICG lymphography

• Secondary outcome variables:

  1. Clinical information: Demographic, disease and treatment-related data
  2. Physical-related: height/weight/waist circumference measurement, body composition test, physical examination (axillary membrane evaluation)
  3. Upper extremity function (shortening of the pectoralis major muscle, adhesive capsulitis): evaluation of shoulder range of motion, upper extremity muscle strength/grip strength
  4. Quality of life assessment: European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30(EORTC QLQ-C30), European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Breast cancer module 23(EORTC QLQ-BR23)

Assessment Schedule:

• Initial treatment and evaluation: Immediately after breast cancer diagnosis
• Follow-up evaluation: Immediately after completion of exercise intervention (preoperatively), and at 1, 3, and 6 months postoperatively.

Number of study subjects:

• This study will be conducted as a preliminary study for future research, and will be conducted on a total of 60 patients (30 in the experimental group and 30 in the control group) with an allocation ratio between groups of 1:1.

Inclusion Criteria:

• Patients aged 20 or older and younger than 80 who were first diagnosed with breast cancer
• Patients scheduled for surgery and starting neoadjuvant chemotherapy before surgery

Exclusion Criteria:

• Patients with medical contraindications to exercise intervention or pain or musculoskeletal conditions that may limit active exercise intervention

• Patients aged 20 or older and younger than 80 years old who were first diagnosed with breast cancer
• Patients scheduled to undergo neoadjuvant chemotherapy before surgery