Endocrine Abstracts

Tumor heterogeneity affects diagnosis, prognosis and response to therapy. Heterogeneity is found in both normal and neoplastic human mammary gland. For example, luminal estrogen receptor (ER)-negative cells can give rise to various phenotypes, including ER-negative and ER-positive mammary tumors, suggesting that the cell-of-origin does not necessarily reflect the tumor type. Regarding ER status, heterogeneity can challenge endocrine therapies; elimination of responsive clones ...