A Randomized Trial Evaluating Bioimpedance Spectroscopy Versus Tape Measurement for the Prevention of Lymphedema Following Treatment for Breast Cancer: Interim Analysis

Sheila H. Ridner, PhD, RN1, Mary S. Dietrich, PhD1,2, Michael S. Cowher, MD3, Bret Taback, MD4, Sarah McLaughlin, MD5, Nicolas Ajkay, MD6, John Boyages, MD, PhD7, Louise Koelmeyer, BAppSc(OT)7, Sarah M. DeSnyder, MD8, Jamie Wagner, DO9, Vandana Abramson, MD10, Andrew Moore, MD11, and Chirag Shah, MD12

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A Randomized Trial Evaluating Bioimpedance Spectroscopy Versus Tape Measurement for the Prevention of Lymphedema Following Treatment for Breast Cancer: Interim Analysis

Sheila H. Ridner, PhD, RN1, Mary S. Dietrich, PhD1,2, Michael S. Cowher, MD3, Bret Taback, MD4, Sarah McLaughlin, MD5, Nicolas Ajkay, MD6, John Boyages, MD, PhD7, Louise Koelmeyer, BAppSc(OT)7, Sarah M. DeSnyder, MD8, Jamie Wagner, DO9, Vandana Abramson, MD10, Andrew Moore, MD11, and Chirag Shah, MD12

Background. Breast cancer-related lymphedema (BCRL) represents a major source of morbidity among breast cancer survivors. Increasing data support early detection of subclinical BCRL followed by early intervention. A randomized controlled trial is being conducted comparing lymphedema progression rates using volume measurements calculated from the circumference using a tape measure (TM) or bioimpedance spectroscopy (BIS).

Methods. Patients were enrolled and randomized to either TM or BIS surveillance. Patients requiring early intervention were prescribed a compression sleeve and gauntlet for 4 weeks and then re-evaluated. The primary endpoint of the trial was the rate of progression to clinical lymphedema requiring complex decongestive physiotherapy (CDP), with progression defined as a TM volume change in the at-risk arm C 10% above the presurgical baseline. This prespecified interim analysis was performed when at least 500 trial participants had C 12 months of follow-up.

Results. A total of 508 patients were included in this analysis, with 109 (21.9%) patients triggering prethreshold interventions. Compared with TM, BIS had a lower rate of trigger (15.8% vs. 28.5%, p\0.001) and longer times to trigger (9.5 vs. 2.8 months, p=0.002). Twelve triggering patients progressed to CDP (10 in the TM group [14.7%] and 2 in the BIS group [4.9%]), representing a 67% relative reduction and a 9.8% absolute reduction (p=0.130).

Conclusions. Interim results demonstrated that post-treatment surveillance with BIS reduced the absolute rates of progression of BCRL requiring CDP by approximately 10%, a clinically meaningful improvement. These results support the concept of post-treatment surveillance with BIS to detect subclinical BCRL and initiate early intervention.

Main findings

  • The results of this interim analysis demonstrate that patients undergoing surveillance with BIS had reduced but non-statistically significant reductions in the rates of progression requiring complex decongestive therapy (CDP) compared with a tape measure (TM). These results are currently supportive of the need for subclinical detection and early intervention for patients with BCRL, with a 10% absolute reduction and 67% relative reduction in the complex decongestive therapy.
  • The interim results reflect a lower rate of triggers in the BIS arm compared with TM (28.5% TM vs. 15.8% BIS). Additionally, the median time to trigger was considerably earlier in the TM group compared with the BIS group (TM median approximately 3 months postsurgery; BIS median approximately 10 months postsurgery). Although the reason for this difference in the time to trigger is currently unknown, we do know that TM detects a change in the whole arm volume, while BIS only detects an extracellular fluid change. It is possible that at 3 months postsurgery there remains, in some patients, a generalized, whole arm inflammatory response that is identified by TM.