This study is a prospective, multi-center, observational post-market safety study evaluating the incidence of anaphylaxis and hypersensitivity reactions associated with LUMISIGHT (pegulicianine) administration in adults with breast cancer undergoing lumpectomy surgery. Participants are indicated to receive LUMISIGHT as part of their breast cancer care. There is no investigational drug associated with this study. LUMISIGHT has a risk of serious hypersensitivity reaction, and this study seeks to further evaluate that risk.