In vivo prediction of response to antiestrogen treatment in estrogen receptor-positive breast cancer.

Unlabelled: In metastatic breast cancer, the estrogen receptor (ER) is a well-known prognostic factor predictive of response to hormonal treatment in most, but not all, patients. Recently, a receptor-specific radioligand for in vivo imaging of the ER in breast cancer patients was developed: (123)I-labeled cis-11beta-methoxy-17alpha-iodovinyl-estradiol (Z-(123)I-MIVE). It showed high sensitivity and specificity for the in vivo detection of ER-positive breast cancer.