Re: Topoisomerase II Alpha and Responsiveness of Breast Cancer to Adjuvant Chemotherapy

Extract

In a correspondence referring to an article by O’Malley et al. ( 1 ), Oakman et al. ( 2 ) argued that, with current evidence, they do not believe that HER2 and TOP2A status predict the potential benefit of anthracycline-based treatments to breast cancer patients. We have graphed the O’Malley data ( Figure 1 ), which clearly showed a predictive value of TOP2A abnormal status for 5-year overall survival following anthracycline-based treatment. Abnormal TOP2A status was associated with poor prognosis irrespective of treatment, and importantly, patients with abnormal TOP2A status had an increased chance of survival when treated with anthracycline (cyclophosphamide, epirubicin, and 5-fluorouracil [CEF]) as opposed to cyclophosphamide, methotrexate, 5-fluorouracil (CMF). Thus, the effect of poor prognosis was counteracted by the positive predictive value. The data from O’Malley et al. ( 1 ) confirmed the Danish results that were first presented in 2005 ( 3 ) and later updated ( 4 ) based on a validation performed in connection with Food and Drug Administration approval of the TOP2A marker.