Impact of Body Mass Index on Clinical Axillary Nodal Assessment in Breast Cancer Patients

Abstract

Background Over one-third of American adults are obese, and an elevated body mass index (BMI) has been postulated to reduce the sensitivity of the clinical evaluation of the axilla. Clinical nodal exam is important in allocating breast cancer patients to appropriate axillary management. We sought to determine whether BMI influences the rate of nodal positivity in women designated clinically node negative (cN0) by physical examination. Methods Breast cancer patients deemed cN0 who underwent sentinel lymph node biopsy (SLNB) from 2/2006–12/2011 were identified from a prospectively maintained database. Clinicopathologic features including BMI and axillary surgery results were recorded and compared among pathologically node-negative and node-positive patients. Results Overall, 5142 cN0 patients underwent 5262 SLNB procedures during the study period. Nearly one-third (28%) of patients were obese (BMI>30kg/m2). A positive SLN was identified in 25% of patients; 84% proceeded to axillary lymph node dissection. Predictors of SLN positivity included younger age, larger tumor size, high nuclear grade, multifocality, and lymphovascular invasion. An increased BMI did not correlate with a higher likelihood of SLN positivity (p=0.6). The likelihood of cN0 patients having a high burden of axillary metastases (>3 positive nodes) was 4% overall and, similarly, did not differ according to BMI (p=0.4). Conclusion Elevated BMI was not associated with a higher likelihood of SLN positivity or heavy nodal disease burden among women staged as cN0 by physical exam. These findings indicate that physical examination is appropriate and sufficient for preoperative axillary evaluation in women undergoing initial surgery regardless of patient BMI.

The Optimal Treatment Plan to Avoid Axillary Lymph Node Dissection in Early-Stage Breast Cancer Patients Differs by Surgical Strategy and Tumor Subtype

“…We have previously reported on a cohort of over 5000 patients with cT1-2N0 breast cancer undergoing SLNB with either BCS or mastectomy and found an overall nodal positivity rate of 25%, with only 6% having ≥3 positive SLNs. 26 In the current cohort of nearly 4000 BCS patients over a 5-year time period, the overall rate of nodal positivity is 17%, with ≤3% requiring ALND across all subtypes. This finding is clinically significant because many surgeons advocate for routine axillary imaging to identify non-palpable axillary metastases in order to triage all node-positive patients to NAC.…”

Axillary Nodal Management Following Neoadjuvant Chemotherapy

“…Although approximately 25% of cN0 patients harbor nodal metastases 34, 35 , fewer than 6% have metastases in ≥3 SLNs%. 51 …”

Overview of Breast Cancer Therapy

“…The axillary nodes are the initial site of metastases in the majority of breast cancer patients, and approximately 25% of those with a normal physical exam will have nodal metastases. 60 The mainstay of axillary staging for almost two decades has been the sentinel lymph node biopsy. With the exception of older patients and those with severe comorbid conditions where information on nodal status will not change therapy, all newly diagnosed invasive breast cancer patients who present with a clinically negative axilla should undergo axillary staging by sentinel lymph node biopsy.…”