National Breast Cancer Surgery Snapshot Study: Breast Cancer Surgery after Neoadjuvant Systemic Therapy in Primary...

Area of Science:

• Oncology
• Surgical Oncology
• Breast Cancer Research

Background:

• Neoadjuvant systemic therapy (NST) use in primary breast cancer is rising globally.
• Understanding the real-world application and outcomes of NST is crucial for optimizing treatment strategies.

Purpose of the Study:

• To analyze the primary reasons for administering NST in breast cancer patients.
• To evaluate the conversion rates from mastectomy to breast-conserving surgery (BCS) post-NST.
• To assess the rates of axillary lymph node dissection (ALND) omission or conversion to axillary sparing surgery following NST.

Main Methods:

• A multicenter, prospective, cross-sectional study involving 70 hospitals in the Netherlands.
• Data collected over 2 months on patient/tumor characteristics, reasons for NST, and pre/post-NST surgical expectations and outcomes.
• Real-time registration of actual surgical procedures performed after NST.

Main Results:

• 467 patients receiving NST were analyzed. Main reasons: axillary down-staging (26%), triple-negative (TN) tumors (25%), and HER2+ tumors (25%).
• NST led to high conversion rates: 47% of patients initially planned for mastectomy underwent BCS. Triple-negative tumors showed the highest conversion rate (68%).
• Axillary conversion from ALND to sparing surgery was achieved in 87% of clinically node-positive (cN+) patients.

Conclusions:

• In the Netherlands, NST is primarily used for specific subtypes (TN, HER2+) and axillary down-staging.
• NST effectively facilitates conversion to BCS and enables omission of ALND, improving surgical outcomes and potentially cosmetic results.
• Real-time data confirms NST's significant impact on surgical conversion rates in breast cancer management.