Background: Axillary staging in women with breast cancer had changed drastically since the concept of sentinel lymph node was introduced. Sentinel lymph node biopsy caused significantly less morbidity than axillary lymph node dissection. The number of nodes removed are variable. However, removing more nodes results in a higher complication rate. If the lymph node with the highest radiologic count could be used to represent the entire group of sentinel nodes then we might be able to limit the number of nodes removed.

Objective: The present study was conducted to find the false negative rate of the sentinel lymph node with various radiologic count in early breast cancer patients.

Material and Method: Women with early stage breast cancer and clinically node negative who had undergone sentinel lymph node biopsy in the breast and endocrine surgery unit of Ramathibodi Hospital between July 1, 2014 and January 31, 2015 were recruited. Radiologic count of each sentinel nodes was documented and the false negative rate of the sentinel node with the highest radiologic count was calculated. False negative rate is defined as the rate of nodal metastasis in lymph nodes other than the node with the highest radiologic count.

Results: One hundred thirty sentinel lymph node biopsies were performed. Of this, 39 women had sentinel lymph node metastasis. The false negative rate of the node with the highest radiologic count is 17.9%. The false negative rate was reduced to 7.7% if we included the second and third highest nodes.

Conclusion: Removal of only the sentinel node with the highest radiologic count has an unacceptably high false negative rate. This can be improved by removing the second and third highest nodes.

Keywords: Sentinel lymph node, Sentinel lymph node biopsy, Early breast cancer, Highest radiologic count