Factors Affecting Lymph Node Yield in Patients Undergoing Axillary Node Dissection for Primary Breast Cancer: A Single-Institution Review

Abstract

A minimum of 10 level I/II axillary nodes is recommended for accurate breast cancer staging. The goal of this study was to assess the effect of neoadjuvant chemotherapy on lymph node yield at axillary lymph node dissection. A single-institution National Comprehensive Cancer Network (NCCN) breast cancer database was queried for cases with axillary node dissection from 2000 to 2008. All dissections were performed at the same institution. Demographic, chemotherapy, and clinicopathologic data were collected. Age and body mass index at diagnosis were calculated for subset analyses. Statistical analyses used Student's t-test or analysis of variance with Tukey multiple comparison and Fisher's exact test. Two hundred forty patients had axillary node dissection after neoadjuvant chemotherapy; an additional 903 women with primary lymph node dissection were identified as contemporaneous control subjects. There was a far lower nodal yield in patients undergoing axillary dissection after neoadjuvant chemotherapy than those undergoing primary surgery. Patients with pathologic stage II or III disease undergoing primary surgery had more lymph nodes at axillary dissection than stage I disease. Age, type of breast surgery, body mass index, and clinical stage have no effect on yield of lymph nodes at axillary lymph node dissection. Neoadjuvant chemotherapy, however, is associated with a far fewer nodes at axillary dissection, and alteration of the guidelines should be considered for this population of patients.