Dermal invasion matters in breast cancer sentinel lymph node biopsy results

Abstract

The aim of this study was to evaluate whether cancer invasion of the dermis could hamper drainage of the radiotracer in breast cancer patients who were undergoing a Sentinel Lymph Node Biopsy (SLNB) procedure. Ten patients who presented with T1-T2 breast cancer with dermal invasion alone as confirmed by a punch biopsy of skin were evaluated. For the SLNB procedure, a lymphoscintigraphy was performed 2 hours after intratumoral administration of 2 mCi (74 MBq) of 99mTc nanocolloid. The sentinel lymph nodes (SLN) were evaluated for the presence of tumor cells by hematoxylin-eosin staining and, when negative, by immunocytochemistry using anti-cytokeratin antibody (CAM 5.2). No migration of radiotracer was found in three patients, and one patient had a false negative SLN, so altogether the technique failed in four patients (40%). Axillary nodes proved to be positive in seven patients (70%).The high rate of failure in the lymphatic mapping and the high proportion of axillary positivity suggest a causal relationship with the invasion of the dermis, with possible implications for the validity of the SLNB procedure.