Lymphedema can be accurately assessed through the use of Bioelectrical Impedance Analysis (BIA) ratios, according to a new study. Since the low-frequency electric current cannot travel through cell membranes, BIA provides a direct measure of lymph fluid outside the cells. This allows for a more accurate assessment of lymphedema using an index called the L-Dex ratio.
Lymphedema is viewed as one of the most feared outcomes of breast cancer treatments. It is a condition that affects the lymphatic system and causes psychosocial distress and physical challenges for patients. Doctors struggle to detect and diagnose it.
“To lessen breast cancer survivors’ worry about lymphedema development, the BIA may have a role in clinical practice by adding confidence in the detection of arm lymphedema among breast cancer survivors, even when pre-surgical BIA baseline measures are not available,” said Mei R. Fu, PhD, RN, ACNS-BC of the New York University College of Nursing in New York City. The study was published in Lymphology (2013;46).
The study sought to examine the reliability, sensitivity, and specificity of cross-sectional assessment of BIA in detecting lymphedema in a large metropolitan clinical setting.
Measuring lymphedema is challenging because most methods cannot distinguish bone and soft tissues from extracellular fluid. BIA is time-efficient, easy to operate and easy to interpret, making it ideal for clinical practice. Fu’s research collected data from 250 women, including healthy female adults, breast cancer survivors with lymphedema, and those at risk for lymphedema. The results demonstrated that survivors with lymphedema had significantly higher L-Dex ratios, which shows the possibility of using BIA to discriminate between those cohorts of women.
“Our study also demonstrated that using a more sensitive L-Dex cutoff point, this allowed for BIA to catch 34% of the usually missed lymphedema cases,” said Fu. “This allows for earlier treatment, which naturally leads to better outcomes for at-risk patients.”
The American Cancer society estimates that in 2013 approximately 232,340 new cases of breast cancer are detected, adding to the already 2.9 million breast cancer survivors, all with a lifetime risk of lymphedema.
“Giving that all the women who are treated for breast cancer are at a lifetime risk for lymphedema, using assessment methods that can accurately identify true lymphedema cases among at-risk breast cancer survivors is of the ultimate importance for clinical practice,” added Fu.