Compositions and formulations comprising chlorotoxin conjugate compounds are provided, including native and modified variants of chlorotoxin peptide conjugated to detectable agents or active agents. Methods of detecting and treating ductal carcinoma in situ breast cancer, invasive ductal carcinoma breast cancer, lobular carcinoma in situ, invasive lobular carcinoma, and triple-negative breast cancer with chlorotoxin conjugate compounds are also provided, including methods of imaging tumor tissues and cells.
