A Prospective Validation Study of Bioimpedance with Volume Displacement in Early-Stage Breast Cancer Patients at Risk for Lymphedema
- 356 Downloads
Although volume displacement (VD) is considered the gold standard for diagnosing breast cancer-related lymphedema, it is inconvenient. We compared bioimpedance (L-Dex) and VD measurements in a prospective cohort of breast cancer patients at risk for lymphedema.
Between 2010 and 2014, a total of 223 breast cancer patients were enrolled. Following exclusions (n = 37), 186 received baseline VD and L-Dex; follow-up measurements were performed at 3–6 months intervals for 3 years. At each visit, patients fitted into one of three categories: normal (normal VD and L-Dex); abnormal L-Dex (L-Dex > 10 or increase in 10 from baseline and normal VD); or lymphedema (relative arm volume difference of >10 % by VD ± abnormal L-Dex). Change in L-Dex was plotted against change in VD; correlation was assessed using the Pearson correlation.
At a median follow-up of 18.2 months, 152 patients were normal, 25 had an abnormal L-Dex, and 9 developed lymphedema without a prior L-Dex abnormality. Of the 25 abnormal L-Dex patients, 4 progressed to lymphedema, for a total of 13 patients with lymphedema. Evaluating all time points, 186 patients had 829 follow-up measurements. Sensitivity and specificity of L-Dex compared with VD were 75 and 93 %, respectively. There was no correlation between change in VD and change in L-Dex at 3 months (r = 0.31) or 6 months (r = 0.21).
VD and bioimpedance demonstrated poor correlation with inconsistent overlap of measurements considered abnormal. Of patients with an abnormal L-Dex, few progressed to lymphedema; most patients with lymphedema did not have a prior L-Dex abnormality. Further studies are needed to understand the clinical significance of bioimpedance.
KeywordsPositive Predictive Value Sentinel Lymph Node Biopsy Negative Predictive Value Lymphedema Axillary Lymph Node Dissection
The authors thank Dr. Kimberly J. Van Zee and Dr. Hiram S. Cody III for their critical review of this manuscript.
This study was a podium presentation at the Society of Surgical Oncology 2015 Annual Cancer Symposium, and was supported by a grant from The Sharpe–Strumia Research Foundation at The Bryn Mawr Hospital, and in part by a National Institutes of Health/National Cancer Institute Cancer Center Support Grant (No. P30 CA008748).