Multicentric breast cancer: a new indication for sentinel node biopsy--a multi-institutional validation study

Area of Science:

• Oncology
• Surgical Oncology
• Pathology

Background:

• Multicentric breast cancer (MCBC) has traditionally been considered a contraindication for sentinel node biopsy (SNB).
• Evaluating the feasibility and accuracy of SNB in MCBC is crucial for refining breast cancer treatment protocols.

Purpose of the Study:

• To assess the feasibility and accuracy of sentinel node biopsy (SNB) in patients with multicentric breast cancer (MCBC).
• To compare SNB outcomes in MCBC patients with those of unicentric breast cancer patients.

Main Methods:

• A prospective multi-institutional trial involving 142 patients with MCBC who underwent SNB.
• Data comparison with 3,216 patients with unicentric breast cancer from the Austrian Sentinel Node Study Group (ASNSG) database.
• Analysis of identification rates, metastasis incidence, and diagnostic accuracy metrics (sensitivity, NPV, overall accuracy).

Main Results:

• SNB identification rate was 91.5%, with a 60.8% incidence of sentinel node metastases.
• High accuracy was demonstrated: sensitivity 96.0%, negative predictive value 93.3%, and overall accuracy 97.3%.
• MCBC patients showed a higher rate of sentinel node and non-sentinel node metastases compared to unicentric cases, but similar detection and false-negative rates.

Conclusions:

• Multicentric breast cancer is a viable indication for sentinel node biopsy (SNB), potentially obviating the need for routine axillary lymph node dissection in controlled settings.
• Successful implementation of SNB in MCBC requires stringent quality control and interdisciplinary collaboration among surgical, nuclear medicine, and pathology teams.
• SNB is demonstrated to be both feasible and accurate for managing multicentric breast cancer.