A study to compare the efficacy of neoadjuvant chemotherapy in locally advanced human epidermal growth factor receptor 2 overexpressing breast cancer.

Background: This prospective single institutional study was conducted to compare the efficacy of the two different neoadjuvant chemotherapy (NACT) regimens in human epidermal growth factor receptor 2 (Her2neu) overexpressing non metastatic breast cancer.

Materials and methods: Patients randomly assigned into two arms in a 1:1 ratio. Arm A received NACT containing docetaxel, doxorubicin, and cyclophosphamide (TAC) regimen. Arm B received NACT containing docetaxel, carboplatin, and trastuzumab (TCH) regimen. Patients underwent surgical intervention following completion of 6 cycles of NACT. Postoperative histopathological reports were compared in terms of pathological response.

Results: 122 patients (Arm A = 61; Arm B = 61) analysed. The mean breast tumor size was 7.724 cm and 7.896 cm in Arm A and Arm B, respectively, at diagnosis and clinical staging. After 6 cycles of NACT, the mean breast tumor size in Arm A and Arm B was 3.495 cm and 3.711 cm, respectively. The Arm A and Arm B exhibited 22.9% and 40.9% of pathological complete response (pCR), respectively, with statistically significant difference (p = 0.033). All patients experienced varying degrees of bone marrow suppression. Grade 2 or 3 chemotherapy induced nausea and vomiting was 37.7% and 23% in Arm A and Arm B, respectively, without statistically significant difference (p = 0.076). 14.8% and 4.9% of patients exhibited febrile neutropenia in Arm A and Arm B, respectively, without statistically significant differences (p = 0.067).

Conclusion: TCH exhibited greater pCR with tolerable adverse reactions in Her2neu overexpressing breast cancer compared to TAC regimen as NACT. Therefore, TCH regimen should be considered for node positive Her2neu overexpressing breast cancer.