Omitting sentinel lymph node biopsy in patients with cT1–2N0 luminal breast cancer: a retrospective cohort analysis and case reports

Background: The need for routine sentinel lymph node biopsy (SLNB) as a component of axillary treatment in patients with early breast cancer and clinically node-negative (cN0) lymph nodes has been debated since the publication of ACOSOG Z0011 data in 2010 [1, 2]. Currently, randomized clinical trials (RCTs) are investigating the possibility of omitting SLNB during breast-conserving surgery with pre- or postoperative chemotherapy and radiation therapy [3, 4]. Prospective RCTs such as SOUND, INSEMA, and BOOG 2013–08 evaluated the oncological safety of omitting sentinel lymph node biopsy with subsequent axillary observation compared to SLNB in patients with cN0 breast cancer [5–7].

Objective: Evaluation of the oncological safety of omitting sentinel lymph node biopsy in patients with luminal cT1–2N0 breast cancer.

Retrospective cohort analysis: The study, conducted at the P.A. Herzen National Medical Research Center of Oncology from 2017 to 2022, included 51 patients with luminal subtypes of primary resectable breast cancer (cT1–2N0) without surgical intervention on the regional lymph node collector. All patients had clinically confirmed cN0 status based on ultrasound imaging. Sentinel lymph node biopsy was not performed; the morphological status of the lymph nodes was designated as pNx. The median age of the patients was 59.1 [51.2; 66.0] years. Stage IA was diagnosed in 44 patients (86.3%), and stage IIA in 7 (13.7%). Left breast cancer was observed in 39 patients (79.5%). Metachronous cancer and multicentricity were detected in 6 patients (11.8%). Invasive ductal carcinoma was diagnosed in 42 patients (82.4%), luminal A subtype in 42 (82.4%), and moderate tumor differentiation in 47 (92.2%). We illustrated various variants of the course of cT1-2N0 breast cancer without intervention on the regional lymph collector with identical baseline patient characteristics.

Results: The median follow-up period was 77.4 [12.6; 78.1] months (range, 12.1 to 80.0). Disease progression was recorded in 5.9% of patients. The regional recurrence rate was 3.9% (n=2). Five-year overall survival and progression-free survival were 100% and 95.2±3.4%, respectively. The median was not reached.

Conclusion: Our study confirms that patients with cT1-2cN0 luminal breast cancer may be candidates for omitting SLNB. No predictors of locoregional recurrence were identified.