Clinical outcomes of de novo metastatic HER2-positive inflammatory breast cancer

Ana C Garrido-Castro; Meredith M Regan; Samuel M Niman; Faina Nakhlis; Claire Remolano; Jennifer M Rosenbluth; Caroline Block; Laura E Warren; Jennifer R Bellon; Eren Yeh; Beth T Harrison; Elizabeth Troll; Nancy U Lin; Sara M Tolaney; Beth Overmoyer; Filipa Lynce

doi:10.1038/s41523-023-00555-w

Clinical outcomes of de novo metastatic HER2-positive inflammatory breast cancer

NPJ Breast Cancer. 2023 Jun 2;9(1):50. doi: 10.1038/s41523-023-00555-w.

Authors

Ana C Garrido-Castro^{1

2

3}, Meredith M Regan^{3

4}, Samuel M Niman⁴, Faina Nakhlis^{2

3

5}, Claire Remolano¹, Jennifer M Rosenbluth^{1

2

3

6}, Caroline Block^{1

2

3}, Laura E Warren^{2

3

7}, Jennifer R Bellon^{2

3

7}, Eren Yeh^{3

8}, Beth T Harrison^{3

9}, Elizabeth Troll¹, Nancy U Lin^{1

2

3}, Sara M Tolaney^{1

2

3}, Beth Overmoyer^{1

2

3}, Filipa Lynce^{10

11

12}

Affiliations

¹ Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
² Breast Oncology Program, Dana-Farber Brigham Cancer Center, Boston, MA, USA.
³ Harvard Medical School, Boston, MA, USA.
⁴ Department of Data Science, Dana-Farber Cancer Institute, Boston, MA, USA.
⁵ Division of Breast Surgery, Department of Surgery, Brigham and Women's Hospital, Boston, MA, USA.
⁶ Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, USA.
⁷ Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
⁸ Department of Radiology, Brigham and Women's Hospital, Boston, MA, USA.
⁹ Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.
¹⁰ Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA. [email protected].
¹¹ Breast Oncology Program, Dana-Farber Brigham Cancer Center, Boston, MA, USA. [email protected].
¹² Harvard Medical School, Boston, MA, USA. [email protected].

Abstract

Inflammatory breast cancer (IBC) is a rare, aggressive form of breast cancer that presents as de novo metastatic disease in 20-30% of cases, with one-third of cases demonstrating HER2-positivity. There has been limited investigation into locoregional therapy utilization following HER2-directed systemic therapy for these patients, and their locoregional progression or recurrence (LRPR) and survival outcomes. Patients with de novo HER2-positive metastatic IBC (mIBC) were identified from an IRB-approved IBC registry at Dana-Farber Cancer Institute. Clinical, pathology, and treatment data were abstracted. Rates of LRPR, progression-free survival (PFS), overall survival (OS), and pathologic complete response (pCR) were determined. Seventy-eight patients diagnosed between 1998 and 2019 were identified. First-line systemic therapy comprised chemotherapy for most patients (97.4%) and HER2-directed therapy for all patients (trastuzumab [47.4%]; trastuzumab+pertuzumab [51.3%]; or trastuzumab emtansine [1.3%]). At a median follow-up of 2.7 years, the median PFS was 1.0 year, and the median OS was 4.6 years. The 1- and 2-year cumulative incidence of LRPR was 20.7% and 29.0%, respectively. Mastectomy was performed after systemic therapy in 41/78 patients (52.6%); 10 had a pCR (24.4%) and all were alive at last follow-up (1.3-8.9 years after surgery). Among 56 patients who were alive and LRPR-free at one year, 10 developed LRPR (surgery group = 1; no-surgery group = 9). In conclusion, patients with de novo HER2-positive mIBC who undergo surgery have favorable outcomes. More than half of patients received systemic and local therapy with good locoregional control and prolonged survival, suggesting a potential role for local therapy.