Development and Validation of a Personalized Digital Healthcare Model for Managing Side Effects in Breast Cancer Survivors

This study is developing and validating a digital health app to help early-stage breast cancer survivors manage the side effects of their treatment (such as arm swelling, pain, and fatigue) at home. The app uses personalized exercise plans and symptom tracking to support recovery. **You may be eligible if...** - You have had surgery for stage 1 or 2 breast cancer - You had a unilateral mastectomy (one breast removed) - You are 18 to 65 years old - You have a smartphone with Android or iOS - You are willing to give written informed consent **You may NOT be eligible if...** - You had a mastectomy but are NOT receiving any follow-up chemotherapy, radiation, or hormone therapy - You have significant health conditions (such as neuromuscular disorders, cognitive impairment, or visual disabilities) that would make it difficult to use the app or do the exercises Talk to your doctor to see if this trial is right for you.