Bioimpedance spectroscopy (BIS) effectively assesses for subclinical breast cancer–related lymphedema (BCRL) in patients at risk, and accurately assess patients for response to treatment, according to a study published in Frontiers in Oncology.1
Advances in breast cancer treatment have improved survival for patients; however, increased survival has also increased the prevalence of chronic sequelae of treatment such as lymphedema. Breast cancer–related lymphedema develops as a result of impaired drainage function of the lymphatic system after sentinel lymph node dissection (SNLD) or axillary lymph node dissection (ALND).
Lymphedema is progressive, costly, and often emotionally devasting for the patient. Traditional diagnostic methods (limb circumference measurements, water displacement, and patient self-report) are limited because they rely on lymphedema being clinically apparent, therefore, lacking sensitivity to detect small changes in extracellular fluid (ECF). These changes have been shown to occur in the early stages of lymphedema, and assessment of the ECF compartment could lead to early detection.
Bioimpedance spectroscopy assesses the ECF compartment, and is shown to detect lymphedema before swelling is visible. Therefore, researchers sought to evaluate the role of BIS in the early detection of breast cancer–related lymphedema and to assess treatment response using the L-Dex U400 unit (ImpediMed Limited, Australia). L-Dex is the score reported by the device that represents the ECF ratio of the at-risk limb to the unaffected limb. The score increases as fluid accumulates in the at-risk limb.
For the study, a retrospective review of 1133 patients (average age 56.2 years) was conducted. Patients were treated between November 2008 and July 2013 at 2 surgical practices, with mean follow-up of 21.7 months. Chart review identified 326 eligible patients who underwent L-Dex measurements before and after surgery. Subclinical lymphedema was defined as asymptomatic with an increase in L-Dex score of more than 10 U above baseline. Patients were stratified by lymph node dissection technique (SLNB vs ALND) and lymphedema treatment.
Of the eligible patients, 210 underwent SLNB and 116 underwent ALND. L-Dex diagnosed lymphedema in 40 patients (12.3%); 9 (4.3%) who had undergone SLNB and 31 (26.7%) who had undergone ALND. Of those patients with subclinical lymphedema diagnosis, 50% of patients experienced resolution with treatment, 27.5% did not experience resolution despite treatment, and 22.5% of patients experienced resolution without treatment. Prevalence of persistent, clinical lymphedema was 0.5% for patients who had undergone SLNB and 8.6% for patients who had undergone ALND.
The researchers conclude that L-Dex measurements are feasible, and implementing the method allows for early detection of breast cancer–related lymphedema and assessment of response to treatment.
1. Laidley A, Anglin B. The impact of L-Dex® measurements in assessing breast cancer-related lymphedema as part of routine clinical practice. Front Oncol. 2016 Sep 5. doi: 10.3389/fonc.2016.00192. [Epub ahead of print]