Clinical, pathological, and molecular predictors of axillary lymph node metastases in young women with breast cancer

Abstract

Introduction/Objective Breast cancer in women shows more aggressive biological characteristics, while the status of axillary lymph nodes remains the most important prognostic factor. The aim of this study was to determine the prevalence of axillary lymph node metastases and to identify histological and immunohistochemical predictors in patients under 40 years of age with breast cancer.

Methods A retrospective cohort study that included patients under 40 years of age with histopathologically confirmed breast cancer who underwent surgical treatment at the Department of Oncological Surgery, Clinical Hospital Center “Bežanijska kosa”, between 2014 and 2024.

Results The study included 97 patients under 40 years of age (mean age 34.75 ± 3.74 years). Axillary lymph node metastases were identified in 48.5% of patients, while sentinel lymph node biopsy was positive in 26.8%. The most common molecular subtype was Luminal B (53.6%). Luminal B tumors were associated with younger age (p = 0.031) and higher body mass index (p = 0.007). HER2-positive and triple-negative tumors were more often of high histological grade (p = 0.003) and larger tumor size (p = 0.025), with a higher Ki-67 proliferation index (p = 0.001). Positive axillary lymph node status was significantly associated with Rh-positive blood type (p = 0.004), tumor size (p = 0.001), and mastectomy (p = 0.004).

Conclusion Breast cancer in women under 40 years of age is characterized by marked biological heterogeneity, with axillary lymph node metastases significantly associated with larger tumor size and more aggressive biological characteristics.

Keywords: breast cancer; biopsy; axillary lymph nodes; molecular subtypes