Ten-Year Analysis of Mastectomy in Stage IV Breast Cancer: Practice Patterns and Outcomes

Area of Science:

• Oncology
• Surgical Oncology
• Breast Cancer Research

Background:

• Current evidence lacks Level 1 data supporting survival benefits of operative therapy for de novo metastatic breast cancer (dnMBC).
• NCCN guidelines currently recommend mastectomy solely for palliation in dnMBC.
• Advancements in multimodal therapies suggest potential benefits for select dnMBC patients with a prolonged disease management continuum.

Purpose of the Study:

• To evaluate the role of primary tumor resection in de novo metastatic breast cancer (dnMBC) within a multimodal treatment approach.
• To compare clinicopathologic factors and patient outcomes between dnMBC patients who underwent mastectomy versus those who did not.

Main Methods:

• Retrospective review of 92 female patients with dnMBC treated between 2014-2024.
• Cohort divided into surgical (mastectomy) and non-surgical groups.
• Analysis of clinicopathologic factors, response to upfront systemic therapy, and overall survival (OS).

Main Results:

• Mastectomy was performed in 40% of patients and was associated with oligometastatic bone disease, not widespread metastasis.
• Surgical patients demonstrated significantly higher rates of complete response (32.4% vs 12.7%) and stable disease (18.9% vs 3.6%) after systemic therapy.
• Non-surgical patients had a higher rate of disease progression (32.7% vs 2.7%), and surgical patients had a higher median OS (NR vs 3.95 years).

Conclusions:

• Primary site surgery can be a valuable component of multimodal management for de novo metastatic breast cancer (dnMBC).
• Further research is needed to identify specific dnMBC patient subgroups who may benefit most from surgical intervention.
• Standardizing surgical care for challenging dnMBC cases requires evaluating patients on the curative-palliative continuum.