TOP2A gene amplification is often accompanied by HER-2 gene amplification (about 30%-50%), which accounts for 8% of all breast cancers and has a poor prognosis.

Treatment of TOP2A amplified breast cancer patients with CEF regimens reduces the risk of recurrence and death, and is a target for anthracyclines

Patients with TOP2A gene deletion have a worse prognosis and should not be treated with anthracyclines.

The efficacy (disease-free and overall survival) of anthracycline-based chemotherapy regimens alone (AC, cyclophosphamide + doxorubicin) in patients with HER-2 and TOP2A co-amplification is comparable to that of AC+Herceptin (clinical data from 3,000 BCIRG 006 in 2011).

Screening of target populations prior to anthracycline administration may reduce side effects such as cardiotoxicity and induction of secondary leukemia associated with them.