Real world study of pertuzumab-trastuzumabchemotherapy versus trastuzumab-chemotherapy in neoadjuvant treatment of breast cancer.

Objective: The primary objective of the study is to compare the  effectiveness of trastuzumab-chemotherapy with and without  pertuzumab. As a secondary objective, we seek to evaluate the cardiac  safety of the treatment.

Method: Retrospective observational study including all patients treated with either pertuzumab-trastuzumab-chemotherapy (n = 10) or  trastuzumab-chemotherapy (n = 13) (January 2015-December 2018) in a specialty hospital, which met the criteria established by the  Commission Central for the Optimization and Harmonization of the  pharmacotherapy of the Andalusian Health Service for the use of  pertuzumab in neoadjuvance: HER2 positive tumor, negative hormonal  receptors, with high risk of relapse (tumor > 2 cm or lymph node  involvement). To assess effectiveness, the complete pathological  response was used. For cardiac safety, the decrease in left ventricular  ejection fraction greater than 10% was employed.

Results: Complete pathological response was superior in the  pertuzumab group (70.0% vs. 30.8%). Cardiac safety was similar in  both.

Conclusions: For patients with HER2 positive tumors and negative hormonal receptors with high risk criteria that receive  pertuzumab, the complete pathological response is superior, with no  increase in cardiac toxicity.