The rate of estrogen receptor-conversion associated with tumor progression in estrogen receptor-positive breast cancer patients following adjuvant Tamoxifen administration.

Background: Hormone Receptor (HR)-discordance between primary breast cancer and metastasis is a known biological phenomenon. Discordance studies usually comprise a heterogeneous group of HR-positive and negative patients and allow for the comparison of changes in HR-status from the primary to the recurrent disease. However, in a clinical setting, the rate of estrogen receptor-conversion following endocrine therapy with agents such as Tamoxifen (TAM) in estrogen receptor-positive cancers is of primary interest as opposed to total receptor discordance.

Effects of the antiestrogens tamoxifen and raloxifene on the estrogen receptor transactivation machinery.

The influence of 17beta-estradiol (E2), tamoxifen (TAM) and raloxifen (RLX) on the proliferation of breast (BC) and endometrial carcinoma cell lines (EC) and the expression of different compounds of the estrogen receptor (ER)-transactivation machinery were studied. E2 stimulated the proliferation of BC, but had no effect on the EC. TAM showed a biphasic effect on ER-positive cell lines.

Regression of cutaneous tumor lesions in patients intratumorally injected with a recombinant single-chain antibody-toxin targeted to ErbB2/HER2.

ScFv(FRP5)-ETA is a recombinant single-chain antibody-toxin with binding specificity for ErbB2/HER2. Previously potent antitumoral activity of the molecule against ErbB2 overexpressing tumor cells was demonstrated in vitro and in animal models. Here we report on the first application of scFv(FRP5)-ETA in human cancer patients summarizing case reports collected in four different clinical centers.