Lymph Node Findings Following Axillary Lymph Node Dissection in Cases of a Positive Sentinel Lymph Node in Breast Cancer

Background Axillary management in breast cancer has undergone significant evolution over recent decades. Sentinel lymph node biopsy (SLNB) has gradually replaced conventional axillary lymph node dissection (ALND) as the preferred staging procedure in clinically node-negative patients, primarily due to its lower morbidity. The role of completion ALND in patients with a positive sentinel lymph node (SLN) remains an area of active investigation, particularly in light of trials supporting less aggressive axillary management. This study aimed to describe the frequency and extent of additional non-sentinel axillary lymph node involvement following completion ALND in patients with a positive SLN, and to explore clinicopathological associations with additional nodal burden. The study was designed as a descriptive and exploratory retrospective analysis. Methodology A retrospective, single-center study was conducted among 102 female patients with histologically confirmed breast cancer who underwent surgery between 2018 and 2019 and were found to have a positive SLN. Data were retrieved from the institutional oncology registry. Patient and tumor characteristics recorded included age, type of breast surgery (breast-conserving surgery (BCS) or mastectomy), TNM staging, histological subtype, tumor grade, hormone receptor (HR) status (estrogen receptor and progesterone receptor), human epidermal growth factor receptor 2 (HER2) status, and Ki-67 proliferation index. Notably, no patient in this cohort received neoadjuvant systemic therapy before surgery. Lymphovascular invasion data were not available in the registry and represent a limitation of this study. Statistical analysis included descriptive and inferential methods using SPSS version 22.0, with p-values <0.05 considered significant. Results The mean patient age was 57.2 ± 13.2 years (range = 28-85). The majority of patients underwent BCS (79.4%, n = 81) rather than mastectomy (20.6%, n = 21). Tumor staging revealed T1 disease in 32.4% (n = 33), T2 in 46.1% (n = 47), and T3 in 5.9% (n = 6); staging data were unavailable for 15.7% of patients. The predominant molecular subtype was luminal (HR+/HER2-) in 75.5% (n = 77), followed by HER2+ (HR+) in 8.8% (n = 9), triple negative in 8.8% (n = 9), and HER2+ (HR-) in 6.9% (n = 7). Tumor grade was 2 in 52.9% (n = 53), grade 3 in 42.2% (n = 43), and grade 1 in 2.0% (n = 2). On average, 3.01 ± 2.4 SLNs were removed (mean positive = 1.7 ± 1.3), and 11.4 ± 5.2 axillary lymph nodes were removed during completion ALND (mean positive = 2.6 ± 3.7). Additional non-sentinel axillary lymph node metastases were identified in 58.8% (n = 60) of patients, while 41.2% (n = 42) had no further nodal disease. Patients with invasive carcinoma demonstrated significantly higher nodal burden (p < 0.05). No statistically significant associations were identified between ALND positivity and age, surgery type, tumor stage, grade, or molecular subtype in this cohort, likely reflecting limited statistical power. Conclusions In this retrospective, single-center study, 58.8% of patients with a positive SLN had additional axillary metastases following completion ALND, underscoring that residual nodal disease remains common and clinically significant. Conversely, 41.2% had no further axillary involvement, consistent with literature supporting selective de-escalation of axillary surgery in carefully selected patients.