This study evaluates whether preoperative shoulder range-of-motion exercises influence postoperative inflammatory response, pain, shoulder function, and quality of life in patients with locally advanced breast cancer undergoing modified radical mastectomy.

Breast cancer patients undergoing modified radical mastectomy are at risk of postoperative pain, shoulder dysfunction, and impaired quality of life, which may be associated with postoperative inflammatory responses. Preoperative rehabilitation strategies, including shoulder range-of-motion exercises, have been proposed to improve postoperative recovery, but evidence in patients with locally advanced breast cancer remains limited.

This study aims to evaluate the effects of a structured preoperative shoulder range-of-motion exercise program on postoperative inflammatory markers, specifically C-reactive protein (CRP), as well as pain intensity, shoulder joint function, and quality of life in patients with locally advanced breast cancer undergoing modified radical mastectomy.

Inclusion Criteria:

• Patients with clinically locally advanced breast cancer (stage IIIA-IIIC according to the American Joint Committee on Cancer staging system) who have been scheduled to undergo modified radical mastectomy.
• Age ≥ 18 years at the time of diagnosis
• Willing to undergo preoperative rehabilitation for 6-8 weeks and to perform the recommended home-based exercise program.
• Willing to participate in follow-up via telephone.

Exclusion Criteria:

• Inability to understand verbal or written communication, resulting in difficulty following exercise instructions.
• Intraoperative complications, such as injury to or transection of the thoracodorsal nerve, long thoracic nerve, and/or intercostobrachial nerve.
• Postoperative complications leading to delayed wound healing, defined as incomplete wound healing at one month after surgery, including wound dehiscence, wound infection, or abscess formation.
• Pre-existing shoulder joint motion limitation diagnosed prior to surgery (e.g., preoperative frozen shoulder).
• Presence of inflammatory conditions in other body regions at the start of or during the study that may result in elevated leukocyte counts, such as diarrhea, urinary tract infection, or skin infection.
• Requirement for nonsteroidal anti-inflammatory drugs (NSAIDs) or systemic corticosteroids for the management of inflammation.

Drop out criteria:

• incomplete follow up
• Unwillingness to undergo repeated blood sampling during the study period.

This study includes female patients diagnosed with locally advanced breast cancer undergoing modified radical mastectomy.

Individual participant data will not be shared because no formal data-sharing plan was included in the ethics-approved study protocol.