Use of a bioimpedance spectroscopy (BIS) device for lymph fluid surveillance showed a non-significant advantage in reducing lymphedema following breast cancer surgery, early results of the randomized PREVENT trial found.
Among women in the study requiring intervention for subclinical lymphedema, 4.9% of those using BIS progressed to clinical lymphedema compared with 14.7% using standard tape measure assessment (P=0.130), reported Sheila Ridner, PhD, RN, of Vanderbilt-Ingram Cancer Center in Nashville, Tennessee.
“We believe that the 10% absolute reduction is clinically significant for this patient population,” Ridner said during a press briefing of the American Society of Breast Surgeons annual meeting. “We also believe that our interim results may support the concept of post-treatment surveillance using BIS for early detection of subclinical lymphedema coupled with early intervention.”
Of the 498 evaluable patients, 15.81% of those in the BIS group (41 of 259) and 28.5% of those in the tape measure group (68 of 239) had an event triggering the need for intervention.
Changes in arm volume ranging from 5% and up to 10% were the trigger for intervention in the tape measure arm of the PREVENT trial, which consisted of using a gauntlet and compression sleeve 12 hours per day for 4 weeks. In the BIS arm, a change of at least 6.5 points on the lymphedema index, or L-Dex, served as a trigger for intervention. Following the intervention, patients were returned to the trial if their measures returned to normal or were sent for lymphedema treatment if they developed lymphedema, defined as an arm circumference increase of 10% on tape measure assessment compared with baseline.
Mean time to these events were 9.5 and 2.8 months in the BIS and tape measure groups, respectively. In all, 12 patients progressed to clinical lymphedema — 10 in the tape measure group and two in the BIS group.
Ridner explained that breast cancer-related lymphedema remains a major source of morbidity and concern among breast cancer survivors who received surgical and other anti-cancer interventions.
“Because it is thought that earlier identification of swelling in the limbs, coupled with a compression intervention may reduce the risk of patients developing full-blown clinical lymphedema, clinicians are proposing to use a prospective surveillance model to follow breast cancer survivors post-surgery,” she said.
Sarah Cate, MD, an associate professor of breast surgery at Icahn School of Medicine at Mount Sinai in New York City, told MedPage Today that surgical interventions such as lymphovascular anastomosis — performed at her institution by plastic surgeons under a microscope — also have a better chance of success when lymphedema is detected early.
As for the study findings, Cate expressed doubt that it would move BIS devices into routine use. “There hasn’t been any major sort of trial showing that it’s of benefit, so I think it’s hard for major academic centers, like where I work, to take it on and say every patient should be using it,” she said.
“I don’t think it’s a practice-changing study,” Cate added, noting that the main findings failed to reach significance, but suggested that perhaps longer follow-up would reveal a benefit with use of the device.
The interim analysis of the PREVENT trial included 508 patients randomized to tape measure circumference or BIS and followed for a minimum of 12 months following surgery (median 17.8 months). The primary endpoint was rate of lymphedema progression that required complex decongestive physiotherapy. At the time of the analysis, 10 patients had already progressed to clinical lymphedema (six in the tape measure group and four in the BIS group). In all, 21.9% (or 109 of the 498 evaluable patients) had a triggering event for intervention.
Median age of patients in the study was 58.8, and 77% were white. Median BMI was 27.9. Eligibility criteria included stage I-III invasive breast cancer or ductal carcinoma in situ — the majority (56.7%) had stage I disease. Patients needed to have undergone at least one of the following interventions:
- Axillary lymph node dissection or sentinel lymph node biopsy with removal of more than 6 nodes
- Mastectomy
- Receipt of taxane-based chemotherapy
- Axillary radiation
Baseline characteristics were similar between the two arms of the study, outside of a statistically significant difference in history of digestive conditions. Post-surgery follow-ups will continue for up to 36 months.
The study was funded by ImpediMed, which manufactures the bioimpedance spectroscopy device used in the trial, and features in-kind donations of garments from medi. The REDCap data capture system was funded by the NIH.
Ridner is employed by Vanderbilt University and serves as principal investigator for studies funded by ImpediMed Inc. and Tactile Medical through contractual agreements between the companies and Vanderbilt University.
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Source: MedicalNewsToday.com
