Chemotherapy Choice in Neoadjuvant Dual Her2 Blockade; Is It Really Necessary to Add Anthracycline?

1. Background Addition of trastuzumab and pertuzumab to neoadjuvant chemotherapy in HER-2 positive patients is the current clinical standard today. In studies on neoadjuvant chemotherapy, the primary endpoint is pathological complete response (pCR). The aim of our study is to answer the following questions: Does the anthracycline containing chemotherapy which will be used alongside dual HER-2 blockade in neoadjuvant treatment has additional benefit? 2. Methods 52 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. All methods were performed in accordance with the relevant guidelines and regulations. 3. Results The mean age of diagnosis was 46 ± 9 (range: 26-67). The pCR rate was 71.2% (37) in the entire study group. In terms of pCR, 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), and 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. Conclusions As 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.