TOP2A IQFISH pharmDx™ is a direct fluorescence in situ hybridization (FISH) assay based on Dako's new fast IQISH hybridization buffer chemistry. The new IQISH hybridization buffer is non-toxic and allows genomic DNA probe hybridization to be performed in just 60-120 minutes. The short hybridization time results in a turnaround time of about 3½ hours for a complete FISH staining from deparaffinization to mounting.

TOP2A IQFISH pharmDx™ is designed to detect amplifications and deletions (copy number changes) of the TOP2A gene using fluorescence in situ hybridization (FISH) technique on formalin-fixed, paraffin-embedded human breast cancer tissue specimens.Deletions and amplifications of the TOP2A gene serve as markers for poor prognosis in high-risk breast cancer patients. TOP2A gene amplification detected by the TOP2A IQFISH pharmDx™ is further indicated as an aid to predict recurrence-free and overall survival in high-risk breast cancer patients treated with adjuvant epirubicin-based chemotherapy.

Results from the TOP2A IQFISH pharmDx™ are intended for use as an adjunct to existing clinical and pathological information. Topoisomerase IIα is a key enzyme involved in DNA replication and is the molecular target for topoisomerase II inhibitor therapies. Clinical research shows that the TOP2A gene can be used as a predictive indicator of susceptibility or resistance to anthracycline therapies (1-3).