Breast cancer patients who receive endocrine therapy particularly aromatase inhibitors often experience aromatase inhibitors associated symptoms (AIMSS) such as joint and muscle pain along with stiffness and fatigue that can disrupt with daily activities and lead some patients to stop treatment early. A structured intervention program named AIMSS-CARE (Aromatase Inhibitor-associated Musculoskeletal Symptoms-Comprehensive Adapted Rehabilitation Evaluation) developed in China that combines exercise, education, symptom monitoring, and follow-up has been shown to reduce these symptoms and improve treatment adherence.

This study will adapt this program for use in Ethiopia while testing its effectiveness to enhance pain management, treatment adherence and quality of life among Ethiopian breast cancer patients receiving endocrine therapy. The study will be conducted at Tikur Anbessa Specialized Hospital in Addis Ababa, Ethiopia.

Eighty-eight patients will be randomly assigned to either the adapted intervention program or usual care. The research will also examine the feasibility and acceptability of the intervention to patients and healthcare providers, and what factors influence its successful implementation. Results will help determine whether this program can be used more widely in Ethiopia and other African cancer centers.

Aromatase-inhibitor-induced musculoskeletal symptoms (AIMSS) are among the most common adverse effects of endocrine therapy for hormone receptor-positive breast cancer and represent a major cause of reduced physical function, poor quality of life, and early discontinuation of therapy. While a multicomponent AIMSS-CARE intervention developed in China has demonstrated significant clinical benefits, no effectiveness or implementation studies have been conducted in settings.

This study aims to culturally adapt and evaluate the effectiveness and implementation of a multicomponent AIMSS intervention among Ethiopian breast cancer patients receiving aromatase inhibitors at Tikur Anbessa Specialized Hospital (TASH). The study uses a Hybrid Type-1 randomized controlled trial design, simultaneously testing clinical effectiveness while collecting data on implementation processes.

A total of 88 eligible participants will be randomly assigned in a 1:1 ratio to either the intervention group or a usual-care control group. The intervention includes home-based exercise training, symptom self-monitoring, nurse-led education on AIMSS management and medication adherence, dietary guidance, and structured follow-up. The intervention will be culturally adapted through stakeholder engagement, language translation, and contextual tailoring.

The primary clinical outcome is musculoskeletal pain measured using the Amharic version of the Brief Pain Inventory. Secondary outcomes include grip strength, health-related quality of life, functional mobility, exercise adherence, medication adherence, and clinician compliance with intervention protocols.

Implementation outcomes will be evaluated using the PARiHS (Promoting Action on Research Implementation in Health Services) framework which provides a way to implement research into practice, including three factors that determine the research use: Evidence(E), Context(C), and Facilitation(F). Data will be collected through qualitative interviews with patients and healthcare providers, intervention delivery audits, and adherence tracking tools.

This study will provide the first evidence on AIMSS intervention effectiveness and implementation in Ethiopia, strengthen oncology nursing practice, and generate a scalable, culturally adaptable model for improving endocrine therapy adherence across African cancer centers.

Inclusion Criteria:

1. Pathologically confirmed hormone receptor-positive (HR+) breast cancer.
2. Aged 18 years or older.
3. Currently receiving aromatase inhibitor therapy (e.g., anastrozole, letrozole, or exemestane) for at least 2 months.
4. Experiencing aromatase inhibitor-induced musculoskeletal symptoms, defined as a worst joint pain score ≥ 2/10 on the Brief Pain Inventory (BPI) during the past 7 days.
5. Capable of understanding the study and willing to sign informed consent.

Exclusion Criteria:

1. History of fracture or major surgery within the past 6 months.
2. Patients diagnosed with arthritis (e.g., rheumatoid arthritis).
3. Patients diagnosed with osteoporosis according to WHO criteria (T-score -2.5).
4. Recurrent or metastatic breast cancer, or receipt of chemotherapy or radiotherapy during the study period.
5. Presence of other primary malignancies.
6. Patients with severe heart, brain, liver, or kidney dysfunction, or infectious diseases.
7. Patients with severe mental, cognitive, or behavioral disorders that hinder understanding or participation in the study.