Neoadjuvant systemic therapy in invasive lobular breast cancer: Is it indicated?

Background: This study investigated patients with invasive lobular breast carcinoma (ILC) to determine the benefit of neoadjuvant systemic therapy (NAST). Methods: Patients with ILC treated from 2006 to 2015 were identified. Tumor characteristics and treatment data were analyzed. Results: Of the 560 patients with ILC, 77 patients received NAST. Patients who received NAST presented with larger clinical T stages compared to patients who received surgery first (p < 0.001). Pathological complete response (pCR) to NAST was seen in 17% of patients. Only 14% of patients with clinically positive lymph nodes downstaged to N0. These patients were more likely to have HER2 positive tumors (p < 0.029) and larger tumor size at diagnosis (p < 0.015). Mastectomy was performed in 84% of patients and lumpectomy in 16%. Conclusions: Only a minority of patients with ILC achieve pCR. The majority of patients still undergo mastectomy; therefore the benefit of NAST in ILC appears limited. (C) 2017 Elsevier Inc. All rights reserved.