Is there a low-grade precursor pathway in breast cancer?
Carcinoma in Situ
Carcinoma, Ductal, Breast
These data do not support a low-grade precursor pathway characterized by LCIS and LG-DCIS. ER/PR and HER2 status have a high rate of concordance between in situ and subsequent invasive lesions. Additional studies of metachronous in situ and invasive lesions are needed to better understand pathways of breast tumorigenesis.