Ultrasound Guided Axillary Node Sampling in Patients of Carcinoma Breast with Clinically Negative Axilla: A Pilot Study

Abstract

Background: The current recommendation for evaluation of axilla in patients with early breast cancers is Sentinel Lymph Node Dissection. Axilllary node sampling (ANS) has been validated as an alternative, but its reliance on palpation for localization of axillary nodes limits its precision. Pre-operative ultrasound guided localization can be combined with ANS to overcome this limitation. We conducted this study to find the accuracy of Ultrasound Guided Axillary Node Sampling (UGANS) in predicting the status of the axilla in patients with breast cancer. Methods: Forty patients of carcinoma breast with clinically negative axilla underwent pre-operative ultrasonography to identify axillary nodes with suspicion of metastatic involvement. Identified nodes were marked on the skin by a permanent marker and depth from the surface was recorded. The patients underwent mastectomy/breast conservation surgery with axillary dissection. The pre-operatively marked nodes were first dissected out under guidance of the skin markings and subsequently complete axillary lymph node dissection (ALND) was performed. Based on histopathological correlation, accuracy of UGANS was calculated taking ALND as the gold standard. Results: Thirty eight (95%) patients had successful marking of axillary nodes by ultrasonography (USG) (Mean 3.89 nodes). Thirty four (85%) patients had successful sampling of marked nodes (Mean-3.76 nodes). There was a higher rate of sampling failure in patients with negative axilla ( 3/17, 17.6%) than those with axillary metastasis ( 1/21, 4 .76% ). Patients in whom marked nodes could not be localized were mostly young (mean age 39 years), had significantly higher body mass index (BMI) score ( mean 31.38 Kg/m2 versus 24.84 kg/m2 , p = 0.006), and smaller size of marked nodes ( mean 0.99 cm in failure group versus 1.03 cm in successful group). The nodes sampled with USG guidance reflected the status of axilla with accuracy of 100% Conclusion: The present study establishes the feasibility and accuracy of UGANS as a potential cost effective axillary staging modality in low resource settings. However, more studies with a larger sample size are required to validate these initial results.