Impact of Neoadjuvant Hormonal Therapy on the Surgical Management of Extensive Ductal Carcinomas in Situ

This study is testing whether hormone therapy given before surgery (neoadjuvant hormonal therapy) can reduce the size of extensive ductal carcinoma in situ (DCIS — a non-invasive breast cancer) enough to potentially allow a less extensive surgery, or to better understand the tumor before a mastectomy. Researchers want to see if this approach changes how surgery is planned and performed. **You may be eligible if you:** - Are 40 years of age or older - Have been diagnosed with DCIS (non-invasive breast cancer) without any invasive component - Have hormone receptor-positive cancer (estrogen receptor positive) - Are scheduled for a mastectomy (full breast removal) - The cancer is visible on MRI **You may NOT be eligible if you:** - Have invasive breast cancer - Have lobular carcinoma in situ - Have cancer that has spread to the lymph nodes - Are eligible for breast-conserving (lumpectomy) surgery instead - Have contraindications to the hormone therapy drug (anastrozole) Talk to your doctor to see if this trial is right for you.