Pioglitazone Therapy Targeting Fatigue in Breast Cancer

This study tests whether pioglitazone — a drug typically used for diabetes — can reduce cancer-related fatigue in women with a specific type of breast cancer (hormone receptor-positive, HER2-negative) who are about to have surgery. **You may be eligible if...** - You have been diagnosed with luminal breast cancer (estrogen and/or progesterone receptor-positive, HER2-negative) confirmed by biopsy - You have not had prior treatment other than neoadjuvant (pre-surgery) chemotherapy - You are scheduled to have a mastectomy within 2 weeks of starting treatment - Your blood counts, blood sugar, and organ function are within normal ranges **You may NOT be eligible if...** - You have HER2-positive breast cancer - You have had prior treatments other than neoadjuvant chemotherapy - You have diabetes or are already taking pioglitazone - Your surgery is not planned within the required timeframe - You have liver, kidney, or bone marrow problems Talk to your doctor to see if this trial is right for you.