Lobular Carcinoma in Situ and Synchronous Malignant Lesions
In summary, high-resolution genome mapping using fresh frozen microdissected samples suggests clonality between classic LCIS and a substantial proportion of adjacent malignant synchronous lesions of lobular and ductal phenotype. Both low-grade and high-grade DCIS and invasive lesions showed high degrees of similarity with patient-matched LCIS. The ER status was concordant in all lesions considered to be clonal or equivocal. These data support the recent theory of breast carcinogenesis where LCIS and ER-positive DCIS are grouped as precursors of ER-positive invasive cancer, and where ER-negative DCIS is a precursor of ER-negative invasive cancer, regardless of histologic grade.
Conclusions
In summary, high-resolution genome mapping using fresh frozen microdissected samples suggests clonality between classic LCIS and a substantial proportion of adjacent malignant synchronous lesions of lobular and ductal phenotype. Both low-grade and high-grade DCIS and invasive lesions showed high degrees of similarity with patient-matched LCIS. The ER status was concordant in all lesions considered to be clonal or equivocal. These data support the recent theory of breast carcinogenesis where LCIS and ER-positive DCIS are grouped as precursors of ER-positive invasive cancer, and where ER-negative DCIS is a precursor of ER-negative invasive cancer, regardless of histologic grade.