Molecular Imaging of Fulvestrant Effects on Availability of ER Binding Sites

Metastatic Breast Cancer Clinical Trial

Official title: In Vivo Imaging of the Effect of Fulvestrant on the Availability of Estrogen Receptor Binding Sites in Metastatic Breast Tumor Lesions Using FES-PET

Status Completed

Clinical Trial Summary

The dose of fulvestrant to optimally downregulate estrogen receptors (ER) is currently subject of debate. Effects of fulvestrant on the ERs may be evaluable by molecular imaging using positron emission tomography with the ER-specific FES tracer. In this pilot study we will evaluate the effects of the new dose of fulvestrant (500mg i.m.)on the availability of ER binding sites in 15 metastatic breast cancer patients.

Clinical Trial Description

The estrogen receptor (ER) is expressed in approximately 70% of the breast carcinomas. In these patients signaling via the ER induces proliferation and cell survival of malignant cells. Fulvestrant can inhibit this signaling route by blocking the receptor and decreasing ER-expression by increasing its turn-over rate. The historical standard dose of fulvestrant was 250mg every 28 days i.m.; however studies performing serial biopsies showed that ER-downregulation was suboptimal. Recently the standard dose has been set to 500mg i.m. on day 1; 14; 28 and every 28 days thereafter. Although slightly more effective than the 250mg dose, still questions remain with respect to the required dose to establish maximal downregulation of ER-signaling. Immunohistochemistry only provides static information, i.e. the level of ER-expression. However, dynamic information evaluating the effects of fulvestrant on occupancy of ERs, may also be valuable. Whole-body imaging of the availability of ER binding sites using FES-PET may prove valuable to evaluate the effects of fulvestrant on the ER non-invasively in individual patients. This potentially allows adjustment of dosing in individual patients to aid therapy efficacy. In this pilot-study we will evaluate 15 metastatic breast cancer patients. All patients will undergo FES-PET/CT at baseline, FES-PET after 1 month, and FES-PET/CT after three months. Hormone- and fulvestrant levels will be measured in all patients. Whenever possible, tumor biopsies will be performed to correlate to FES-PET results. ;

Related Conditions & MeSH terms

• Breast Neoplasms
• Metastatic Breast Cancer

• NCT number: NCT01377324
• Study type: Interventional
• Source: University Medical Center Groningen
• Status: Completed
• Phase: Phase 2
• Start date: May 2011
• Completion date: August 2013