Chemotherapy Choice in Neoadjuvant Dual Her2 Blockade; is it Really Necessary to add Anthracycline?

Abstract 1. BackgroundAddition of trastuzumab and pertuzumab to neoadjuvant chemotherapy in human epidermal growth factor receptor 2(HER-2) positive patients is the current clinical standard today. In studies on neoadjuvant chemotherapy, the primary endpoint is pathological complete response (pCR). More real-life data are needed to answer whether the presence of anthracycline in the chemotherapy regimen enhances complete response with neoadjuvant dual HER-2 blockade, and whether cardiotoxicity increases with dual HER-2 blockade after anthracycline.2. Methods52 patients with HER-2 positive breast cancer who received neoadjuvant chemotherapy were retrospectively evaluated. Three centers participated in the study (İzmir Kent Hospital, Manisa Celal Bayar University, Ege University). The effects of chemotherapy regimen and several other factors such as age, stage, menopause status, lymph node positivity, hormone receptor positivity on pCR were evaluated. Also presence of cardiotoxicity was evaluated.3. ResultsThe mean age of diagnosis was 46 ± 9 (range: 26-67), and 50% (26) of the patients were postmenopausal. The pCR rate was 71.2% (37) in the entire study group. In terms of pCR, there was no significant difference between those who use an anthracycline containing and non-anthracycline containing regimens (71.4% vs 70%, p=1.000), those with negative and positive hormone receptors (64.7% vs 74.3%, p=0.525), those with Ki67 levels of %20 or less and those over 20% (60% vs 73.8%, p=0.447), premenopausal and postmenopausal ones (76.9% vs 65.4%, p=0.054). 4. ConclusionsAs a result of the data we obtained, it was concluded that adding anthracycline regimen to dual HER-2 blockade in the neoadjuvant period did not bring additional benefits in terms of pCR. Additional studies are needed on whether the use of anthracycline-containing regimen contributes additionally in patients who will use the neoadjuvant pertuzumab-trastuzumab combination.