Magtrace for Delayed Sentinel Lymph Node Biopsy in Patients with Ductal Carcinoma In-Situ
This phase II trial tests how well Magtrace, a new iron-based mapping agent, can help avoid unnecessary sentinel lymph node biopsies (SLNBs) in patients with ductal carcinoma in-situ (DCIS). The standard of care for DCIS is to perform a mastectomy with an SLNB. In an SLNB, doctors use mapping agents (blue dye or technetium) to locate and remove a few lymph nodes for testing. These mapping agents clear from the body within 1–2 days. While SLNB carries some risk, such as long-term arm swelling (lymphedema), DCIS itself rarely spreads to lymph nodes unless invasive cancer is present. Examining the breast tissue after mastectomy shows whether the cancer is invasive or remains DCIS. In this study, Magtrace will be used during the mastectomy to map the lymph nodes. Instead of removing the lymph nodes right away at the same time as mastectomy for biopsy, the surgeon will wait until the final pathology results are available from surgery to learn whether the cancer is invasive and therefore more likely to have spread. Magtrace may safely allow patients to avoid SLNB at the time of mastectomy while still ensuring accurate lymph node mapping if SLNB is later required.