Does a Positive Axillary Lymph Node Needle Biopsy Result Predict the Need for an Axillary Lymph Node Dissection in Clinically Node-Negative Breast Cancer Patients in the ACOSOG Z0011 Era?

Abstract

American College of Surgeons Oncology Group (ACOSOG) Z0011 defined clinical node negativity by physical examination alone. Although axillary ultrasound with biopsy has a positive predictive value for lymph node (LN) metastases approaching 100%, it may not appropriately identify clinically node-negative women with ≥3 positive LNs who require axillary lymph node dissection (ALND). We sought to identify the total number of positive LNs in women presenting with cT1-2N0 breast carcinoma with a positive preoperative LN biopsy to evaluate the potential for overtreatment when ALND is performed on the basis of a positive needle biopsy in patients who otherwise meet ACOSOG Z0011 eligibility criteria. Patients with cT1-2N0 breast cancer by physical examination with a positive preoperative LN biopsy were identified from a prospective institutional database. Clinicopathologic characteristics and axillary imaging results were compared between women with 1 to 2 total positive LNs and ≥3 total positive LNs. Between May 2006 and December 2013, a total of 141 women with cT1-2N0 breast cancer had abnormal axillary imaging and a preoperative positive LN biopsy (median patient age 51years, median tumor size 2.4cm, 86% ductal histology, 79% estrogen receptor positive). Sixty-six women (47%) had 1 to 2 total positive LNs, and 75 (53%) had ≥3 total positive LNs. Women with ≥3 total positive LNs had larger tumors (2.4 vs. 2.2cm, p=0.03), fewer tumors with ductal histology (79 vs. 94%, p=0.01), more lymphovascular invasion (80 vs. 61%, p=0.01), and higher median body mass index (29.2 vs. 27.1kg/m(2), p=0.04). Having >1 abnormal LN on axillary imaging was significantly associated with having ≥3 total positive LNs at final pathology (68 vs. 43%, p=0.003). Axillary imaging with preoperative LN biopsy does not accurately discriminate low- versus high-volume nodal disease in clinically node-negative patients.