By Megan Brooks
NEW YORK (Reuters Health) - 8/5/2019
For triggering compression therapy to prevent progression of breast cancer-related lymphedema, bioimpedance spectroscopy (BIS) appears to be more effective than standard tape measure (TM) assessment of arm circumference, according to interim results of the PREVENT trial reported May 2 at the American Society of Breast Surgeons annual meeting.
Fewer women in the trial went on to develop clinical lymphedema when referred for therapy using BIS than traditional TM, suggesting that BIS is a "highly effective tool for pinpointing patients at risk," Dr. Sheila Ridner of Vanderbilt University in Nashville, Tennessee, said in a statement.
"Despite advances in breast-conserving surgery, improved radiation protocols, the advent of certain biopsies and chemotherapy regimens, breast cancer related-lymphedema remains a major source of morbidity and concern in this patient population," Dr. Ridner said during a media briefing.
The aim of the PREVENT trial is to determine whether subclinical detection of extracellular fluid accumulation using BIS and subsequent early intervention reduces the rate of lymphedema progression relative to rates seen using standard TM.
Participants in the PREVENT trial are women with stage I to III breast cancer or ductal carcinoma in situ having at least one of the following treatments: mastectomy, axillary treatment (axillary lymph node dissection, sentinel lymph node biopsy with greater than 6 nodes, axillary radiation) or taxane-based chemotherapy.
The interim analysis included 259 women randomized to BIS using the L-DEX device (ImpediMed) and 239 to standard TM. Beginning at 90 days after surgery, the women were regularly assessed and followed for a minimum of one year.
Women in the TM group who experienced an increase in arm circumference of 5% or more, indicating subclinical lymphedema, were treated with compression therapy. For women in the BIS group, an increase of 6.5 L-DEX units from baseline, also reflective of a subclinical lymphedema, triggered compression therapy. For both groups, clinical lymphedema was defined as a 10% increase in arm circumference with TM assessment.
Overall, 109 women (22%) met the threshold that triggered compression therapy, including 68 women (28.5%) in the TM group and 41 women in the BIS group (15.8%). Ten of the 68 women in the TM group (14.7%) later progressed to clinical lymphedema requiring decongestive therapy versus two of the 41 in the BIS group (4.9%), representing a 67% relative reduction and a 9.8% absolute reduction (P=0.130) using BIS.
"These findings mean that women could potentially avoid this debilitating condition if BIS screening were the norm," Dr. Ridner said in a statement.
Commenting on the results for Reuters Health, Dr. Hank Schmidt, breast cancer surgeon with the Mount Sinai Health System in New York, said, "The L-DEX device used in the study has been available for several years but I think the data are still evolving. This trial has been going on for a while and this is an interim analysis."
"The results are exciting," Dr. Schmidt said by phone, "because they show that it's feasible to do and it looks like it does a good job of detecting very early signs of lymphedema so that patients can be put into care pathways to try to prevent progression, which is the goal."
The PREVENT trial is funded by ImpediMed Inc. Dr. Ridner serves as principal investigator for studies funded by ImpediMed Inc.
American Society of Breast Surgeons Annual Meeting 2019.