Science et thérapie du cancer

Improved Fat Clearance Techniques for the Examination of Breast Cancer Lymph Nodes

Abstract

Fabiana Resende Rodrigues, Andréa Rodrigues Cordovil Pires, Eliene Carvalho de Fonseca, Samantha Cunha Gomes Antunes, Calina Maria Loures de Oliveira Teixeira, Licínio Esmeraldo da Silva, Nathalie Henriques Silva Canedo and Mayra Carrijo Rochael

Introduction: The isolation of lymph nodes less than 4.0 mm in diameter from the fatty tissue of surgical breast cancer specimens through the traditional method of tactile perception is difficult, time consuming and failed the identification of smaller lymph nodes. The reported numbers of lymph nodes detected through this technique vary widely in the literature demonstrating its inappropriateness. The use of fat clearance techniques however may contribute to the isolation of additional nodes, allowing for appropriate pathological staging of the disease.

Objective: To evaluate the impact of the use of fat clearance machinery and solutions in the dissection and identification of lymph nodes from axillary dissections of patients with breast cancer.

Materials and methods: Fat clearance techniques (cooker, electric spiral, modified Koren clearing solution and formaldehyde-acetic alcohol solution) were applied to 100 breast cancer axillary dissections from males and females with no age restriction over a period of two years (2009-2011).

Results: Through the use of fat clearance methods, additional 174 metastases in 564 lymph nodes were found, more than the classical method, from which 449 metastases in 1426 lymph nodes were identified. There was no statistical difference between the fat clearance methods; however the cooker method demonstrated greater efficiency than the modified Koren clearing solution method. Conclusion: The fat clearance methods described here have various advantages over the classical method. These methods are viable, rapid, practical, inexpensive and do not alter the quality of histological analysis or immunohistochemical reactions. The findings show that examination of a minimum of 20 isolated lymph nodes is necessary for optimal identification and diagnosis of lymph node metastases. The main outcome from this study were the immediate benefits generated by adopting new technical procedures resulting in a change in pathological staging classification in 14% of the patients.